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User Manual
D-Settlement
Embankment design and soil settlement prediction
D-SETTLEMENT
Embankment design and soil settlement prediction
User Manual
Version: 16.1
Revision: 00
9 February 2016
D-SETTLEMENT
, User Manual
Published and printed by:
Deltares
Boussinesqweg 1
2629 HV Delft
P.O. 177
2600 MH Delft
The Netherlands
telephone: +31 88 335 82 73
fax: +31 88 335 85 82
e-mail: info@deltares.nl
www: https://www.deltares.nl
For sales contact:
telephone: +31 88 335 81 88
fax: +31 88 335 81 11
e-mail: sales@deltaressystems.nl
www: http://www.deltaressystems.nl
For support contact:
telephone: +31 88 335 81 00
fax: +31 88 335 81 11
e-mail: support@deltaressystems.nl
www: http://www.deltaressystems.nl
Copyright © 2016 Deltares
All rights reserved. No part of this document may be reproduced in any form by print, photo
print, photo copy, microfilm or any other means, without written permission from the publisher:
Deltares.
Contents
Contents
1 General Information 1
1.1 Foreword ................................... 1
1.2 Features in standard module ......................... 1
1.2.1 Soil profile .............................. 2
1.2.2 Loads ................................ 2
1.2.3 Models ................................ 2
1.2.4 Results ................................ 3
1.3 Features in additional modules ........................ 3
1.3.1 Fits on settlement plate measurements . . . . . . . . . . . . . . . . 3
1.3.2 Reliability analysis .......................... 3
1.3.3 Horizontal displacements . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 History .................................... 4
1.5 Limitations .................................. 6
1.5.1 Darcy vs. Terzaghi .......................... 7
1.5.2 NEN-Koppejan vs. NEN-Bjerrum/Isotache . . . . . . . . . . . . . . 7
1.6 Minimum System Requirements . . . . . . . . . . . . . . . . . . . . . . . 8
1.7 Definitions and Symbols ........................... 8
1.8 Getting Help ................................. 10
1.9 Getting Support ................................ 10
1.10 Deltares ................................... 11
1.11 Deltares Systems ............................... 12
1.12 Acknowledgements .............................. 12
2 Getting Started 13
2.1 Starting D-Settlement ............................. 13
2.2 Main Window ................................. 13
2.2.1 The menu bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2.2 The icon bar ............................. 15
2.2.3 View Input window . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.4 Title panel .............................. 18
2.2.5 Status bar .............................. 18
2.3 Files ..................................... 19
2.4 Tips and Tricks ................................ 19
2.4.1 Keyboard shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.4.2 Exporting figures and reports . . . . . . . . . . . . . . . . . . . . . 19
2.4.3 Copying part of a table . . . . . . . . . . . . . . . . . . . . . . . . 20
2.4.4 Continuous display of the results in time or depth . . . . . . . . . . . 20
3 General 21
3.1 File menu ................................... 21
3.2 Tools menu .................................. 22
3.2.1 Program Options – View . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.2 Program Options – General . . . . . . . . . . . . . . . . . . . . . . 23
3.2.3 Program Options – Locations . . . . . . . . . . . . . . . . . . . . . 24
3.2.4 Program Options – Language . . . . . . . . . . . . . . . . . . . . . 24
3.2.5 Program Options – Modules . . . . . . . . . . . . . . . . . . . . . 25
3.3 Help menu .................................. 25
3.3.1 Error Messages ........................... 26
3.3.2 Manual ................................ 26
3.3.3 Deltares Systems Website . . . . . . . . . . . . . . . . . . . . . . 26
3.3.4 Support ................................ 26
3.3.5 About D-Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . 26
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4 Input 27
4.1 Project menu ................................. 27
4.1.1 Model ................................ 27
4.1.2 Probabilistic Defaults ......................... 28
4.1.3 Project Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.1.4 View Input File . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.2 Soil menu ................................... 34
4.2.1 Materials – Database ......................... 34
4.2.2 Materials – Parameters Terzaghi . . . . . . . . . . . . . . . . . . . 35
4.2.3 Materials – Parameters Darcy . . . . . . . . . . . . . . . . . . . . 37
4.2.4 Materials – Parameters Isotache . . . . . . . . . . . . . . . . . . . 38
4.2.5 Materials – Parameters NEN-Bjerrum . . . . . . . . . . . . . . . . . 39
4.2.6 Materials – Parameters NEN-Koppejan . . . . . . . . . . . . . . . . 41
4.2.7 Materials – Reliability Analysis . . . . . . . . . . . . . . . . . . . . 43
4.2.8 Materials – Horizontal Displacements . . . . . . . . . . . . . . . . . 44
4.3 Geometry menu ............................... 45
4.3.1 New ................................. 45
4.3.2 New Wizard ............................. 45
4.3.3 Import ................................ 49
4.3.4 Import from Database . . . . . . . . . . . . . . . . . . . . . . . . 50
4.3.5 Export ................................ 50
4.3.6 Export as Plaxis/DOS ......................... 50
4.3.7 Limits ................................. 51
4.3.8 Points ................................ 51
4.3.9 Import PL-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.3.10 PL-lines ............................... 52
4.3.11 Phreatic Line ............................. 53
4.3.12 Layers ................................ 53
4.3.13 PL-lines per Layer . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.3.14 Check Geometry ........................... 56
4.4 GeoObjects menu .............................. 56
4.4.1 Verticals ............................... 56
4.4.2 Vertical Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.5 Water menu .................................. 61
4.5.1 Water Properties ........................... 62
4.6 Loads menu ................................. 62
4.6.1 Non-Uniform Loads . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.6.2 Water Loads ............................. 65
4.6.3 Other Loads ............................. 66
4.6.3.1 Tank Loads ......................... 69
5 Calculations 73
5.1 Calculation Options .............................. 73
5.1.1 Calculation Options – 1D geometry . . . . . . . . . . . . . . . . . . 73
5.1.2 Calculation Options – 2D geometry . . . . . . . . . . . . . . . . . . 74
5.2 Calculation Times ............................... 77
5.3 Fit for Settlement Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
5.3.1 Fit for Settlement Plate – Measurements . . . . . . . . . . . . . . . 77
5.3.2 Fit for Settlement Plate – Materials . . . . . . . . . . . . . . . . . . 79
5.4 Start Calculation ............................... 82
5.4.1 Regular (deterministic) analysis . . . . . . . . . . . . . . . . . . . . 82
5.4.2 Reliability and sensitivity analysis . . . . . . . . . . . . . . . . . . . 83
5.4.3 Error Messages (before calculation) . . . . . . . . . . . . . . . . . 86
5.4.4 Warnings and Error Messages during calculation . . . . . . . . . . . 86
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5.5 Batch Calculation ............................... 86
6 View Results 89
6.1 Report Selection ............................... 89
6.2 Report .................................... 90
6.2.1 Stresses per vertical (Terzaghi) . . . . . . . . . . . . . . . . . . . . 91
6.2.2 Settlements per vertical (NEN-Koppejan with Terzaghi) . . . . . . . . 92
6.2.3 Stresses, heads and settlements per vertical (Darcy) . . . . . . . . . 93
6.2.4 Settlements .............................. 93
6.2.5 Residual Settlements ......................... 94
6.2.6 Maintain Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.2.7 Warnings and errors ......................... 95
6.3 Stresses in Geometry ............................. 96
6.4 Dissipations .................................. 96
6.5 Time-History ................................. 98
6.5.1 Time-History – Terzaghi . . . . . . . . . . . . . . . . . . . . . . . 98
6.5.2 Time-History – Darcy ......................... 99
6.6 Depth-History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
6.6.1 Depth-History – Terzaghi . . . . . . . . . . . . . . . . . . . . . . . 100
6.6.2 Depth-History – Darcy . . . . . . . . . . . . . . . . . . . . . . . . 102
6.7 Residual Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.8 Settled Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.9 Write Settled Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6.10 Write D-Geo Stability Input . . . . . . . . . . . . . . . . . . . . . . . . . . 105
6.11 Time-History (Reliability) . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
6.12 Influencing Factors (Reliability) . . . . . . . . . . . . . . . . . . . . . . . . 106
6.13 Residual Settlements (Reliability) . . . . . . . . . . . . . . . . . . . . . . . 107
7 Graphical Geometry Input 109
7.1 Geometrical objects ..............................109
7.1.1 Geometry elements . . . . . . . . . . . . . . . . . . . . . . . . . . 109
7.1.2 Construction elements . . . . . . . . . . . . . . . . . . . . . . . . 110
7.2 Assumptions and restrictions . . . . . . . . . . . . . . . . . . . . . . . . . 110
7.3 View Input Window ..............................110
7.3.1 General ................................110
7.3.2 Buttons ................................112
7.3.3 Legend ................................114
7.4 Geometry modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
7.4.1 Create a new geometry . . . . . . . . . . . . . . . . . . . . . . . . 116
7.4.2 Set limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
7.4.3 Draw layout ..............................117
7.4.4 Generate layers . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
7.4.5 Add piezometric level lines . . . . . . . . . . . . . . . . . . . . . . 119
7.5 Graphical manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
7.5.1 Selection of elements . . . . . . . . . . . . . . . . . . . . . . . . . 119
7.5.2 Deletion of elements . . . . . . . . . . . . . . . . . . . . . . . . . 121
7.5.3 Using the right-hand mouse button . . . . . . . . . . . . . . . . . . 121
7.5.4 Dragging elements . . . . . . . . . . . . . . . . . . . . . . . . . . 124
7.6 Working With 1D Geometries . . . . . . . . . . . . . . . . . . . . . . . . . 124
7.6.1 Creating a 1D Geometry . . . . . . . . . . . . . . . . . . . . . . . 124
7.6.2 Converting a 2D Geometry into a 1D Geometry . . . . . . . . . . . . 125
7.6.3 The 1D Geometry Input Window . . . . . . . . . . . . . . . . . . . 125
8 Tutorial 1: Building site preparation 127
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8.1 Introduction ..................................127
8.2 Project ....................................128
8.2.1 Create New Project . . . . . . . . . . . . . . . . . . . . . . . . . . 128
8.2.2 Project Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 129
8.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
8.3.1 Layer boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
8.3.2 Piezometric lines . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
8.3.3 Phreatic Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
8.3.4 PL-lines per Layer . . . . . . . . . . . . . . . . . . . . . . . . . . 132
8.4 Soil types and properties . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
8.5 Layers ....................................134
8.6 Loads .....................................135
8.7 Verticals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
8.8 Calculation ..................................137
8.8.1 Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . 137
8.8.2 Calculation Times . . . . . . . . . . . . . . . . . . . . . . . . . . 137
8.8.3 Start Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
8.9 Results basic analysis (Tutorial-1a) . . . . . . . . . . . . . . . . . . . . . . 138
8.9.1 Time-History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
8.9.2 Depth-History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
8.9.3 Residual Settlement . . . . . . . . . . . . . . . . . . . . . . . . . 141
8.10 Influence of submerging (Tutorial-1b) . . . . . . . . . . . . . . . . . . . . . 142
8.11 Comparison of consolidation models (Tutorial-1c and 1d) . . . . . . . . . . . 143
8.11.1 Terzaghi consolidation . . . . . . . . . . . . . . . . . . . . . . . . 143
8.11.2 Drained behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
8.12 Influence of initial overconsolidation . . . . . . . . . . . . . . . . . . . . . . 146
9 Tutorial 2: Embankment design with vertical drains 149
9.1 Introduction ..................................149
9.2 Project ....................................152
9.2.1 Importing an existing geometry . . . . . . . . . . . . . . . . . . . . 152
9.2.2 Importing material properties from an MGeobase database . . . . . . 153
9.3 Initial embankment design (Tutorial-2a) . . . . . . . . . . . . . . . . . . . . 154
9.3.1 Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
9.3.2 Verticals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
9.3.3 Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . 157
9.3.4 Time-History results . . . . . . . . . . . . . . . . . . . . . . . . . 157
9.4 Acceleration of the consolidation process by means of vertical drains (Tutorial-
2b) ......................................159
9.4.1 Vertical Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
9.4.2 Time-History results . . . . . . . . . . . . . . . . . . . . . . . . . 160
9.4.3 Stability analysis with D-Geo Stability . . . . . . . . . . . . . . . . . 161
9.4.4 Dissipations results . . . . . . . . . . . . . . . . . . . . . . . . . . 164
9.5 Staged loading (Tutorial-2c) . . . . . . . . . . . . . . . . . . . . . . . . . . 166
9.6 Temporary pre-loading by soil raise (Tutorial-2d) . . . . . . . . . . . . . . . 170
9.7 Additional enforced dewatering (Tutorial-2e) . . . . . . . . . . . . . . . . . . 171
9.8 Horizontal Displacements (Tutorial-2f) . . . . . . . . . . . . . . . . . . . . . 174
9.8.1 Principles of De Leeuw method . . . . . . . . . . . . . . . . . . . . 174
9.8.2 Evaluation of the elasticity modulus . . . . . . . . . . . . . . . . . . 174
9.8.3 Input for horizontal displacements . . . . . . . . . . . . . . . . . . 175
9.8.4 Calculated horizontal displacements . . . . . . . . . . . . . . . . . 176
9.9 Bandwidth Determination (Tutorial-2g) . . . . . . . . . . . . . . . . . . . . 177
9.10 Conclusion ..................................184
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10 Tutorial 3: Settlement plate fit 185
10.1 Actual loading steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
10.2 Initial prediction (Tutorial-3a) . . . . . . . . . . . . . . . . . . . . . . . . . 186
10.3 Settlement plate fit (Tutorial-3b) . . . . . . . . . . . . . . . . . . . . . . . . 190
10.4 Band width after settlement plate fit (Tutorial-3c) . . . . . . . . . . . . . . . 195
10.5 Conclusion ..................................197
11 Tutorial 4: Ground improvement 199
11.1 Introduction ..................................199
11.2 Project ....................................201
11.2.1 Soil and Consolidation Models . . . . . . . . . . . . . . . . . . . . 201
11.2.2 Project Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 202
11.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
11.3.1 Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
11.3.2 Points ................................202
11.3.3 PL-line / Phreatic line . . . . . . . . . . . . . . . . . . . . . . . . . 203
11.3.4 Layers ................................204
11.4 Method 1 for ground improvement . . . . . . . . . . . . . . . . . . . . . . . 205
11.4.1 Soil properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
11.4.2 Loads ................................206
11.4.3 Verticals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
11.4.4 Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . 210
11.4.5 Results of Method 1 . . . . . . . . . . . . . . . . . . . . . . . . . 210
11.5 Method 2 for ground improvement . . . . . . . . . . . . . . . . . . . . . . . 211
11.5.1 Defining the Sand layer . . . . . . . . . . . . . . . . . . . . . . . . 211
11.5.2 Modeling the soil improvement . . . . . . . . . . . . . . . . . . . . 212
11.5.3 Results of Method 2 . . . . . . . . . . . . . . . . . . . . . . . . . 213
11.6 Comparison of both ground improvement methods . . . . . . . . . . . . . . 214
11.7 Conclusion ..................................216
12 Tutorial 5: Enforced dewatering by sand screens (IFCO) 217
12.1 Introduction ..................................217
12.1.1 Excavation and loading stages . . . . . . . . . . . . . . . . . . . . 218
12.1.2 Subsoil characterization . . . . . . . . . . . . . . . . . . . . . . . 218
12.1.3 Drainage using sand screens and dewatering . . . . . . . . . . . . . 220
12.2 Project ....................................220
12.2.1 Importing an existing geometry . . . . . . . . . . . . . . . . . . . . 220
12.2.2 Model ................................221
12.3 Importing material properties from a database . . . . . . . . . . . . . . . . 221
12.4 Piezometric Levels ..............................223
12.4.1 Phreatic Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
12.4.2 PL-lines per Layer . . . . . . . . . . . . . . . . . . . . . . . . . . 223
12.5 Loads .....................................223
12.5.1 Modelling the soil improvement . . . . . . . . . . . . . . . . . . . . 224
12.5.2 Modelling the embankment construction . . . . . . . . . . . . . . . 225
12.6 Verticals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
12.7 Vertical Drains ................................226
12.8 Calculation Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
12.9 Results ....................................226
12.9.1 Settlements vs. time curve . . . . . . . . . . . . . . . . . . . . . . 227
12.9.2 Residual settlements vs. time curve . . . . . . . . . . . . . . . . . . 227
12.9.3 Excess hydraulic head vs. depth curve . . . . . . . . . . . . . . . . 227
12.9.4 Effect of the enforced air underpressure (Tutorial-5b) . . . . . . . . . 228
12.9.5 Effect of dewatering (Tutorial-5c) . . . . . . . . . . . . . . . . . . . 229
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12.10 Conclusion ..................................230
13 Loads 231
13.1 Non-uniform loads ..............................231
13.2 Trapeziform loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
13.3 Circular loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
13.4 Rectangular loads ..............................233
13.5 Uniform loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
13.6 Maintain profile ................................233
13.7 Submerging ..................................234
13.7.1 Submerging – Approximate method (Terzaghi or NEN-Koppejan) . . . 234
13.7.2 Submerging – Accurate method (Darcy + Isotache/NEN-Bjerrum) . . . 234
13.8 Water loads ..................................235
14 Distribution of stress by loading 237
14.1 General equations for stress distribution . . . . . . . . . . . . . . . . . . . . 237
14.1.1 Stress increments caused by a surface point force . . . . . . . . . . 237
14.1.2 Stress increments caused by a line load . . . . . . . . . . . . . . . 238
14.2 Stress distribution for a strip load . . . . . . . . . . . . . . . . . . . . . . . 238
14.3 Stress distribution for a circular load . . . . . . . . . . . . . . . . . . . . . . 239
14.4 Stress distribution for a rectangular load . . . . . . . . . . . . . . . . . . . . 240
14.5 Imaginary surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
15 Pore pressure 243
15.1 Hydraulic head distribution . . . . . . . . . . . . . . . . . . . . . . . . . . 243
15.1.1 Piezometric level lines . . . . . . . . . . . . . . . . . . . . . . . . 243
15.1.2 Phreatic line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
15.1.3 Stress by soil weight . . . . . . . . . . . . . . . . . . . . . . . . . 244
15.2 Terzaghi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
15.2.1 Terzaghi – General consolidation theory . . . . . . . . . . . . . . . 245
15.2.2 Terzaghi – Consolidation of multi-layered systems . . . . . . . . . . 246
15.2.3 Terzaghi – Drainage conditions . . . . . . . . . . . . . . . . . . . . 246
15.2.4 Terzaghi – Effective stress and pore pressure . . . . . . . . . . . . . 246
15.3 Darcy .....................................247
15.3.1 Darcy – Consolidation theory . . . . . . . . . . . . . . . . . . . . . 247
15.3.2 Darcy – Drainage conditions . . . . . . . . . . . . . . . . . . . . . 249
15.3.3 Darcy – Effective stress and pore pressure . . . . . . . . . . . . . . 249
15.3.4 Darcy – Numerical solution . . . . . . . . . . . . . . . . . . . . . . 249
15.4 Vertical drains ................................249
15.4.1 Modified storage equation . . . . . . . . . . . . . . . . . . . . . . 250
15.4.2 Line-shaped vertical drains (strip/column drains) . . . . . . . . . . . 251
15.4.3 Plane-shaped vertical drains (plane flow) . . . . . . . . . . . . . . . 252
15.5 Comparison of the consolidation models . . . . . . . . . . . . . . . . . . . 253
16 Soil and strain models 255
16.1 NEN-Bjerrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
16.1.1 NEN-Bjerrum – Idealized behavior . . . . . . . . . . . . . . . . . . 256
16.1.2 NEN-Bjerrum – Mathematical Formulation . . . . . . . . . . . . . . 257
16.2 Isotache a/b/c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
16.2.1 Isotache – Natural strain . . . . . . . . . . . . . . . . . . . . . . . 259
16.2.2 Isotache – Creep . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
16.3 NEN-Koppejan ................................262
16.3.1 NEN-Koppejan – Settlement . . . . . . . . . . . . . . . . . . . . . 262
16.3.2 NEN-Koppejan – Swelling . . . . . . . . . . . . . . . . . . . . . . 263
16.3.3 NEN-Koppejan – Natural strain . . . . . . . . . . . . . . . . . . . . 264
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17 Determining soil parameters 265
17.1 Oedometer tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
17.1.1 Description ..............................265
17.1.2 Simulating an oedometer test with D-settlement . . . . . . . . . . . . 265
17.2 Overconsolidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
17.3 NEN-Bjerrum parameter determination . . . . . . . . . . . . . . . . . . . . 266
17.4 Isotache parameters determination . . . . . . . . . . . . . . . . . . . . . . 268
17.5 NEN-Koppejan parameter determination . . . . . . . . . . . . . . . . . . . 270
17.5.1 Primary and secular compression coefficients . . . . . . . . . . . . 270
17.5.2 Primary and Secondary swelling coefficients . . . . . . . . . . . . . 271
17.6 NEN-Bjerrum parameters from Koppejan parameters . . . . . . . . . . . . . 271
17.6.1 For a single load . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
17.6.2 From oedometer test results . . . . . . . . . . . . . . . . . . . . . 271
17.7 Isotache a/b/c parameter conversion . . . . . . . . . . . . . . . . . . . . . 272
17.7.1 Linear NEN-Bjerrum parameters . . . . . . . . . . . . . . . . . . . 273
17.7.2 Linear NEN-Koppejan parameters . . . . . . . . . . . . . . . . . . 274
17.7.3 Natural and linear Cam-Clay-creep parameters . . . . . . . . . . . . 274
18 Special Calculations 277
18.1 Fit for settlement plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
18.2 Reliability analysis ..............................278
18.2.1 Stochastic distributions and parameters . . . . . . . . . . . . . . . . 278
18.2.2 Initial and updated parameter covariance . . . . . . . . . . . . . . . 280
18.2.3 Sensitivity analysis with influencing factors . . . . . . . . . . . . . . 281
18.2.4 Probabilistic methods . . . . . . . . . . . . . . . . . . . . . . . . . 281
18.3 Horizontal displacements . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
18.3.1 Principles of De Leeuw method . . . . . . . . . . . . . . . . . . . . 282
18.3.2 Limitations ..............................283
18.3.3 E-Modulus ..............................284
19 Benchmarks 285
Bibliography 287
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x Deltares
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List of Figures
1.1 Deltares Systems website (www.deltaressystems.com) . . . . . . . . . . . . 10
1.2 Support window, Problem Description tab ................... 11
1.3 Send Support E-Mail window ......................... 11
2.1 Modules window ............................... 13
2.2 D-Settlement main window . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3 D-Settlement menu bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4 D-Settlement icon bar ............................. 15
2.5 View Input window, Input tab . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.6 View Input window, Top View tab . . . . . . . . . . . . . . . . . . . . . . . 16
2.7 Selection of different parts of a table using the arrow cursor . . . . . . . . . . 20
3.1 New File window ............................... 21
3.2 Program Options window, View tab . . . . . . . . . . . . . . . . . . . . . . 22
3.3 Program Options window, General tab . . . . . . . . . . . . . . . . . . . . 23
3.4 Program Options window, Locations tab . . . . . . . . . . . . . . . . . . . . 24
3.5 Program Options window, Language tab ................... 24
3.6 Program Options window, Modules tab . . . . . . . . . . . . . . . . . . . . 25
3.7 Error Messages window ........................... 26
4.1 Model window ................................ 27
4.2 Probabilistic Defaults window, Consolidation and unit weight tab . . . . . . . 28
4.3 Probabilistic Defaults window, Compression tab . . . . . . . . . . . . . . . . 29
4.4 Project Properties window, Identification tab . . . . . . . . . . . . . . . . . 30
4.5 Project Properties window, View Input tab . . . . . . . . . . . . . . . . . . 31
4.6 Project Properties window, Stresses in Geometry tab . . . . . . . . . . . . . 32
4.7 Project Properties window, Settled Geometry tab . . . . . . . . . . . . . . . 33
4.8 Materials window, Database tab ....................... 35
4.9 Materials window, Consolidation and unit weight tab for Terzaghi model . . . . 36
4.10 Materials window, Consolidation and unit weight tab for Darcy model . . . . . 37
4.11 Materials window, Compression tab for Isotache model . . . . . . . . . . . . 38
4.12 Materials window, Compression tab for NEN-Bjerrum model (Input as ratio) . . 40
4.13 Materials window, Compression tab for NEN-Bjerrum model (Input as index) . 41
4.14 Materials window, Compression tab for NEN-Koppejan model . . . . . . . . . 42
4.15 Materials window, Compression tab for reliability analysis . . . . . . . . . . . 43
4.16 Materials window, Horizontal displacements tab . . . . . . . . . . . . . . . . 44
4.17 New Wizard window, Basic Layout . . . . . . . . . . . . . . . . . . . . . . 46
4.18 New Wizard window, Top Layer Shape screen . . . . . . . . . . . . . . . . 46
4.19 New Wizard window, Top Layer Specification screen . . . . . . . . . . . . . 47
4.20 New Wizard window, Material types screen . . . . . . . . . . . . . . . . . . 48
4.21 New Wizard window, Summary screen . . . . . . . . . . . . . . . . . . . . 49
4.22 Select geometry window ........................... 50
4.23 Geometry Limits window ........................... 51
4.24 Points window ................................ 51
4.25 Confirm window for deleting used points ................... 52
4.26 PL-Lines window ............................... 52
4.27 Phreatic Line window ............................. 53
4.28 Layers window, Boundaries tab . . . . . . . . . . . . . . . . . . . . . . . . 53
4.29 Layers window, Materials tab ......................... 54
4.30 PL-lines per Layer window .......................... 55
4.31 Information window on confirmation of a valid geometry . . . . . . . . . . . . 56
4.32 Verticals window ............................... 56
4.33 Vertical Drains window (Drain Type sub-window) . . . . . . . . . . . . . . . 57
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4.34 Vertical Drains window, Strip and Column drains (Positioning input) . . . . . . 57
4.35 Vertical Drains window, Strip and Column drains (Drainage Schedule input) . . 58
4.36 Vertical Drains window, Sand wall (Positioning input) . . . . . . . . . . . . . 60
4.37 Vertical Drains window, Sand wall (Drainage Schedule input) . . . . . . . . . 60
4.38 Water Properties window ........................... 62
4.39 Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.40 Import Gamma Wet/Dry from Database window . . . . . . . . . . . . . . . . 64
4.41 Generate Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . 64
4.42 Water Loads window ............................. 65
4.43 Other Loads window with Trapeziform load . . . . . . . . . . . . . . . . . . 66
4.44 Other Loads window with Circular load . . . . . . . . . . . . . . . . . . . . 67
4.45 Other Loads window with Rectangular load . . . . . . . . . . . . . . . . . . 68
4.46 Other Loads window with Uniform load . . . . . . . . . . . . . . . . . . . . 69
4.47 Other Loads window with Tank load . . . . . . . . . . . . . . . . . . . . . . 70
4.48 Generate Uniform Loads window . . . . . . . . . . . . . . . . . . . . . . . 71
5.1 Calculation Options window for 1D geometry . . . . . . . . . . . . . . . . . 73
5.2 Calculation Options window for 2D geometry . . . . . . . . . . . . . . . . . 75
5.3 Calculation Times window . . . . . . . . . . . . . . . . . . . . . . . . . . 77
5.4 Fit for Settlement Plate window, Measurements tab . . . . . . . . . . . . . . 78
5.5 Fit for Settlement Plate window, Materials tab . . . . . . . . . . . . . . . . . 79
5.6 Iteration stop criteria window . . . . . . . . . . . . . . . . . . . . . . . . . 80
5.7 Plate Test Calculation Progress window . . . . . . . . . . . . . . . . . . . . 81
5.8 Time-History (Fit) window ........................... 81
5.9 Available results after a fit ........................... 81
5.10 Start Calculation window for a regular analysis . . . . . . . . . . . . . . . . 83
5.11 Start Calculation window for a reliability and sensitivity analysis . . . . . . . . 84
5.12 Error Messages window ........................... 86
5.13 Start Calculation window, messages pane . . . . . . . . . . . . . . . . . . 86
5.14 Run window ................................. 86
5.15 Start Batch Calculation window . . . . . . . . . . . . . . . . . . . . . . . . 87
5.16 D-settlement Calculation window during batch calculation . . . . . . . . . . . 87
6.1 Report Selection window ........................... 90
6.2 Report window – Stresses per vertical (Terzaghi) . . . . . . . . . . . . . . . 91
6.3 Report window – Settlement per vertical (NEN-Koppejan with Terzaghi) . . . . 92
6.4 Report window, Results per Vertical section (Darcy) . . . . . . . . . . . . . 93
6.5 Report window – Settlements ......................... 94
6.6 Report window – Residual settlements . . . . . . . . . . . . . . . . . . . . 94
6.7 Report window – Maintain Profile Calculation Results . . . . . . . . . . . . . 95
6.8 Report window – Warnings and errors . . . . . . . . . . . . . . . . . . . . 95
6.9 Stresses in Geometry window . . . . . . . . . . . . . . . . . . . . . . . . 96
6.10 Dissipations window ............................. 97
6.11 Time-History window for Terzaghi consolidation . . . . . . . . . . . . . . . . 98
6.12 Time-History window for Darcy consolidation . . . . . . . . . . . . . . . . . 99
6.13 Depth-History window for Terzaghi consolidation model . . . . . . . . . . . . 101
6.14 Depth-History window for Darcy consolidation model . . . . . . . . . . . . . 102
6.15 Residual Settlement window . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.16 Settled Geometry window . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6.17 Write Settled Geometry window . . . . . . . . . . . . . . . . . . . . . . . . 104
6.18 Write D-Geo Stability Input File window . . . . . . . . . . . . . . . . . . . . 105
6.19 Confirm window for replacement of database values . . . . . . . . . . . . . 105
6.20 Time-History (Reliability) window . . . . . . . . . . . . . . . . . . . . . . . 106
6.21 Influencing Factors (Reliability) window . . . . . . . . . . . . . . . . . . . . 107
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6.22 Residual Settlement (Reliability) window . . . . . . . . . . . . . . . . . . . 107
7.1 View Input window, Geometry tab . . . . . . . . . . . . . . . . . . . . . . 111
7.2 View Input window, Geometry tab (legend displayed as Layer Numbers). . . 114
7.3 Legend, Context menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
7.4 View Input window, Geometry tab (legend displayed as Material Numbers). . 115
7.5 Legend, Context menu (for legend displayed as Materials). . . . . . . . . . 115
7.6 Color window .................................116
7.7 View Input window, Geometry tab . . . . . . . . . . . . . . . . . . . . . . 116
7.8 Right Limit window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
7.9 Representation of a polyline . . . . . . . . . . . . . . . . . . . . . . . . . . 117
7.10 Examples of configurations of (poly)lines . . . . . . . . . . . . . . . . . . . 118
7.11 Modification of the shape of a berm . . . . . . . . . . . . . . . . . . . . . . 118
7.12 Example of invalid point not connected to the left limit . . . . . . . . . . . . . 119
7.13 Selection accuracy as area around cursor . . . . . . . . . . . . . . . . . . . 120
7.14 Selection accuracy as area around cursor . . . . . . . . . . . . . . . . . . . 120
7.15 Selection accuracy as area around cursor . . . . . . . . . . . . . . . . . . . 120
7.16 Example of deletion of a point . . . . . . . . . . . . . . . . . . . . . . . . . 121
7.17 Example of deletion of a geometry point . . . . . . . . . . . . . . . . . . . 121
7.18 Example of deletion of a line . . . . . . . . . . . . . . . . . . . . . . . . . 121
7.19 Pop-up menu for right-hand mouse menu (Select mode) . . . . . . . . . . . 122
7.20 Layer window (Property editor of a layer) . . . . . . . . . . . . . . . . . . . 123
7.21 Point window (Property editor of a point) . . . . . . . . . . . . . . . . . . . 123
7.22 Boundary window (Property editor of a polyline) . . . . . . . . . . . . . . . 123
7.23 Boundary window (Property editor of a line) . . . . . . . . . . . . . . . . . . 123
7.24 PL-line window (Property editor of a PL-line) . . . . . . . . . . . . . . . . . 124
7.25 Example of dragging of a point . . . . . . . . . . . . . . . . . . . . . . . . 124
7.26 2D-1D Conversion Location window . . . . . . . . . . . . . . . . . . . . . . 125
7.27 1D Geometry window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
8.1 Layers and loading (Tutorial 1) . . . . . . . . . . . . . . . . . . . . . . . . 128
8.2 New File window ...............................128
8.3 View Input window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
8.4 Project Properties window, Identification tab . . . . . . . . . . . . . . . . . 130
8.5 Project Properties window, View Input tab . . . . . . . . . . . . . . . . . . 130
8.6 View Input window, after input of single lines and piezometric lines . . . . . . 131
8.7 Points window ................................132
8.8 Phreatic Line window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
8.9 PL-lines per Layer window ..........................132
8.10 Materials window, Consolidation and unit weight tab for Clay Sandy . . . . . 133
8.11 Materials window, Compression tab for Clay Sandy . . . . . . . . . . . . . . 133
8.12 Layers window, Materials tab . . . . . . . . . . . . . . . . . . . . . . . . . 134
8.13 Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . . . . . . 135
8.14 View Input window, Input tab . . . . . . . . . . . . . . . . . . . . . . . . . 136
8.15 Verticals window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
8.16 Calculation Options window . . . . . . . . . . . . . . . . . . . . . . . . . . 137
8.17 Calculation Times window . . . . . . . . . . . . . . . . . . . . . . . . . . 138
8.18 Start Calculation window . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
8.19 Time-History window, Effective stress and Settlement at surface level . . . . . 139
8.20 Chart Data window, Surface settlement versus Time . . . . . . . . . . . . . 139
8.21 Time-History window, Excess hydraulic head at depth 3.5 m . . . . . . . . . 140
8.22 Time-History window, Effective stress in the drained pleistocene sand, gradu-
ally decreasing by submerging of the top layer . . . . . . . . . . . . . . . . 140
8.23 Depth-History window, Excess head before and after unloading . . . . . . . . 141
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8.24 Residual Settlement window . . . . . . . . . . . . . . . . . . . . . . . . . 141
8.25 Calculation Options window . . . . . . . . . . . . . . . . . . . . . . . . . . 142
8.26 Time-History window, Surface settlement with submerging switched off (Tutorial-
1b) ......................................142
8.27 Model window ................................143
8.28 Time-History window, Surface settlement for Terzaghi model and no submerg-
ing (Tutorial-1c) ................................144
8.29 Chart Data window, Surface settlement versus Time (Tutorial-1c) . . . . . . . 144
8.30 Dissipations window, Degree of consolidation versus Time in Clay Organic
layer for Terzaghi model and no submerging (Tutorial-1c) . . . . . . . . . . . 145
8.31 Time-History window, Surface Settlements using Drained layers and no sub-
merging (Tutorial-1d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
8.32 Surface Settlements compared (no submerging) . . . . . . . . . . . . . . . 146
8.33 Materials window with reduced OCR (Tutorial-1e) . . . . . . . . . . . . . . . 147
8.34 Time-History window, Surface settlement with reduced OCR (Tutorial-1e) . . . 147
8.35 Surface Settlements compared (no submerging) . . . . . . . . . . . . . . . 148
8.36 Time-History window, Excess head (at depth 3.5 m) with reduced OCR (Tutorial-
1e) ......................................148
9.1 Embankment geometry (Tutorial 2) . . . . . . . . . . . . . . . . . . . . . . 150
9.2 New File window ...............................152
9.3 View Input window, Geometry tab after importing geometry . . . . . . . . . . 153
9.4 Program Options window, Locations tab . . . . . . . . . . . . . . . . . . . . 153
9.5 Materials window, Database tab . . . . . . . . . . . . . . . . . . . . . . . 154
9.6 Information window ..............................154
9.7 Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . . . . . . 155
9.8 Verticals window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
9.9 View Input window, Input tab showing the generated verticals (Tutorial-2a) . . 156
9.10 Calculation Options window . . . . . . . . . . . . . . . . . . . . . . . . . . 157
9.11 Time-History window, Natural consolidation: Settlement and Effective stress
vs. Time in vertical 4 (Tutorial-2a) . . . . . . . . . . . . . . . . . . . . . . . 158
9.12 Time-History window, Natural consolidation: Excess head vs. Time in vertical
4 at RL-4.875m (Tutorial-2a) . . . . . . . . . . . . . . . . . . . . . . . . . 158
9.13 Time-History window, placeCityGreenfield settlement in vertical 1 (Tutorial-2a) 159
9.14 Model window, Select Vertical drains option (Tutorial-2b) . . . . . . . . . . . 159
9.15 Vertical Drains window (Tutorial-2b) . . . . . . . . . . . . . . . . . . . . . . 160
9.16 View Input window, Input tab (Tutorial-2b) . . . . . . . . . . . . . . . . . . . 160
9.17 Time-History window, Consolidation with vertical drains: Settlement and Ef-
fective stress vs. Time in vertical 4 (Tutorial-2b) . . . . . . . . . . . . . . . . 161
9.18 Time-History window, Consolidation with vertical drains: Excess head vs.
Time in vertical 4 at RL -4.875 m (Tutorial-2b) . . . . . . . . . . . . . . . . . 161
9.19 Write D-Geo Stability Input File window (Tutorial-2b) . . . . . . . . . . . . . 162
9.20 D-Geo Stability View Input window (Tutorial-2b) . . . . . . . . . . . . . . . . 162
9.21 D-Geo Stability Slip Circle Definition window (Tutorial-2b) . . . . . . . . . . . 163
9.22 D-Geo Stability Degree of Consolidation window (Tutorial-2b) . . . . . . . . . 163
9.23 D-Geo Stability slip circle result (Tutorial-2b) . . . . . . . . . . . . . . . . . 164
9.24 Start Calculation window (Tutorial-2b) . . . . . . . . . . . . . . . . . . . . . 164
9.25 Dissipations window, Degree of consolidation vs. Time in Peat at vertical 4,
for grid distance 1 m (Tutorial-2b) . . . . . . . . . . . . . . . . . . . . . . . 165
9.26 Dissipations window, Degree of consolidation vs. Time in Peat at vertical 4,
for grid distance 2 m (Tutorial-2b) . . . . . . . . . . . . . . . . . . . . . . . 165
9.27 8-staged loading (Tutorial-2c) . . . . . . . . . . . . . . . . . . . . . . . . . 166
9.28 Generate Non-Uniform Loads window (Tutorial-2c) . . . . . . . . . . . . . . 166
9.29 Non-Uniform Loads window, Final load (Tutorial-2c) . . . . . . . . . . . . . . 167
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List of Figures
9.30 View Input window, Input tab (Tutorial-2c) . . . . . . . . . . . . . . . . . . . 167
9.31 Calculation Times window (Tutorial-2c) . . . . . . . . . . . . . . . . . . . . 168
9.32 Time-History window, Settlement and Effective stress vs. Time in vertical 4 for
drain distance 2 m (Tutorial-2c) . . . . . . . . . . . . . . . . . . . . . . . . 168
9.33 Time-History window, Excess head vs. Time in vertical 4 at RL-4.875 m for
drain distance 2 m (Tutorial-2c) . . . . . . . . . . . . . . . . . . . . . . . . 169
9.34 Residual Settlement window for drain distance 2 m (Tutorial-2c) . . . . . . . . 169
9.35 Chart Data window (Tutorial-2c) . . . . . . . . . . . . . . . . . . . . . . . . 170
9.36 Residual Settlement window for drain distance 1 m (Tutorial-2c) . . . . . . . . 170
9.37 Non-Uniform Loads window, Temporary preloading 1 m (Tutorial-2d) . . . . . 171
9.38 Residual Settlement window (Tutorial-2d) . . . . . . . . . . . . . . . . . . . 171
9.39 Installation Beau Drain system (Tutorial-2e) . . . . . . . . . . . . . . . . . . 172
9.40 Non-Uniform Loads window, Temporary preloading 0.5 m (Tutorial-2e) . . . . 172
9.41 Vertical Drains window, Drainage Schedule input (Tutorial-2e) . . . . . . . . . 173
9.42 Time-History window, Excess head vs. Time in vertical 4 at RL-4.875 m, with
enforced dewatering (Tutorial-2e) . . . . . . . . . . . . . . . . . . . . . . . 173
9.43 Time-History window, Effective stress vs. Time in vertical 4 at RL-4.875 m,
with enforced dewatering (Tutorial-2e) . . . . . . . . . . . . . . . . . . . . . 174
9.44 Model window (Tutorial-2f) ..........................175
9.45 Materials window (Tutorial-2f) . . . . . . . . . . . . . . . . . . . . . . . . . 176
9.46 Depth-History window, Horizontal Displacements at vertical 3 (Tutorial-2f) . . . 177
9.47 Model window (Tutorial-2g) ..........................178
9.48 Probabilistic Defaults window (Tutorial-2g) . . . . . . . . . . . . . . . . . . 179
9.49 Materials window for Clay (Tutorial-2g) . . . . . . . . . . . . . . . . . . . . 180
9.50 Materials window for Peat (Tutorial-2g) . . . . . . . . . . . . . . . . . . . . 181
9.51 Materials window for Sand (Pleistocene) (Tutorial-2g) . . . . . . . . . . . . . 182
9.52 Calculation Times window for Bandwidth determination (Tutorial-2g) . . . . . 183
9.53 Start Calculation window for Monte Carlo reliability analysis (Tutorial-2g) . . . 183
9.54 Time-History (Reliability) window, Total settlement vs. Time with Band width
for Monte Carlo method (Tutorial-2g) . . . . . . . . . . . . . . . . . . . . . 184
9.55 Residual Settlement (Reliability) window (Tutorial-2g) . . . . . . . . . . . . . 184
10.1 Actual loading stages for Tutorial 3 . . . . . . . . . . . . . . . . . . . . . . 186
10.2 Non-Uniform Loads window, First load . . . . . . . . . . . . . . . . . . . . 187
10.3 Non-Uniform Loads window, Last load . . . . . . . . . . . . . . . . . . . . 188
10.4 Vertical Drains window . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
10.5 Calculation Times window . . . . . . . . . . . . . . . . . . . . . . . . . . 189
10.6 Time-History window, Settlements and Effective stress at surface level vs.
Time for vertical 4 (Tutorial-3a) . . . . . . . . . . . . . . . . . . . . . . . . 189
10.7 Model window ................................190
10.8 Open window .................................190
10.9 Fit for Settlement Plate window, Measurements tab (Tutorial-3b) . . . . . . . 191
10.10 Fit for Settlement Plate window, Materials tab (Tutorial-3b) . . . . . . . . . . 192
10.11 Time-History (Fit) window, Initial prediction versus measurement, imperfection
0.19 m (Tutorial-3b) ..............................192
10.12 Fit for Settlement Plate window, Materials tab, Details of the Fit Results (Tutorial-
3b) ......................................193
10.13 Iteration stop criteria window (Tutorial-3b) . . . . . . . . . . . . . . . . . . . 193
10.14 Fit for Settlement Plate window, Materials tab, Fit factors after fit (Tutorial-3b) . 194
10.15 Time-History (Fit) window, Prediction vs. measurement after fit, imperfection
0.04 m (Tutorial-3b) ..............................194
10.16 Start Calculation window . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
10.17 Start Calculation window, Monte Carlo using fit parameters (Tutorial-3c) . . . . 196
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10.18 Time-History (Reliability) window, Total settlement vs. Time with Band width
for Monte Carlo method (Tutorial-3c) . . . . . . . . . . . . . . . . . . . . . 196
10.19 Residual Settlement (Reliability) window (Tutorial-3c) . . . . . . . . . . . . . 197
11.1 Ground improvement and embankment construction in three stages (Tutorial 4) 199
11.2 New File window ...............................201
11.3 Model window ................................201
11.4 Geometry Limits window . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
11.5 Points window ................................203
11.6 Pl-Lines window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
11.7 Phreatic line window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
11.8 Layers window, Boundaries tab . . . . . . . . . . . . . . . . . . . . . . . . 204
11.9 Layers window, Materials tab . . . . . . . . . . . . . . . . . . . . . . . . . 205
11.10 View Input window, Input tab . . . . . . . . . . . . . . . . . . . . . . . . . 205
11.11 Materials window, Compression tab for Peat . . . . . . . . . . . . . . . . . 206
11.12 Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . . . . . . 207
11.13 Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . . . . . . 208
11.14 Generate Non-Uniform Loads window . . . . . . . . . . . . . . . . . . . . . 208
11.15 View Input window, Input tab . . . . . . . . . . . . . . . . . . . . . . . . . 209
11.16 Verticals window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
11.17 Calculation Options window . . . . . . . . . . . . . . . . . . . . . . . . . . 210
11.18 Time-History window for vertical 1 (Tutorial-4a) . . . . . . . . . . . . . . . . 211
11.19 Non-Uniform Loads window (Tutorial-4b) . . . . . . . . . . . . . . . . . . . 212
11.20 Start Calculation window (Tutorial-4b) . . . . . . . . . . . . . . . . . . . . . 213
11.21 Time-History window for vertical 1 (Tutorial-4b) . . . . . . . . . . . . . . . . 213
11.22 Depth-History window (Tutorial-4b) after 10000 days . . . . . . . . . . . . . 214
11.23 Chart Data window (vertical 1 of Tutorial-4b) . . . . . . . . . . . . . . . . . 215
11.24 Settlement vs. Time – Comparison between methods 1 and 2 . . . . . . . . . 215
11.25 Effective stress vs. Time – Comparison between methods 1 and 2 . . . . . . 216
12.1 General view with pre-loading and sand walls (Tutorial 5) . . . . . . . . . . . 217
12.2 Geometry of the excavation and pre-loading phases (Tutorial 5) . . . . . . . . 218
12.3 Layers in the subsoil (Tutorial 5) . . . . . . . . . . . . . . . . . . . . . . . . 219
12.4 IFCO system (sand walls) . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
12.5 New File window ...............................220
12.6 View Input window, Geometry tab after importing geometry . . . . . . . . . . 221
12.7 Program Options window, Locations tab . . . . . . . . . . . . . . . . . . . . 222
12.8 Materials window, Database tab . . . . . . . . . . . . . . . . . . . . . . . 222
12.9 PL-lines per Layer window ..........................223
12.10 Non-Uniform Loads window, Initial state and Excavation loads . . . . . . . . 224
12.11 Non-Uniform Loads window, Fill and Embankment loads . . . . . . . . . . . 225
12.12 Vertical Drains window for Sand wall . . . . . . . . . . . . . . . . . . . . . 226
12.13 Calculation Times window . . . . . . . . . . . . . . . . . . . . . . . . . . 226
12.14 Time-History window, dewatering with underpressure (Tutorial-5a) . . . . . . 227
12.15 Residual Settlement window, dewatering with underpressure (Tutorial-5a) . . . 227
12.16 Depth-History window, excess head at 10000 days (Tutorial-5a) . . . . . . . . 228
12.17 Time-History window, dewatering without underpressure (Tutorial-5b) . . . . . 229
12.18 Time-History window, no dewatering (Tutorial-5c) . . . . . . . . . . . . . . . 229
12.19 Residual Settlements window, no enforced dewatering (Tutorial-5c) . . . . . . 230
12.20 Settlement results for different cases (Tutorial-5) . . . . . . . . . . . . . . . 230
13.1 Non-uniform load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
13.2 Trapeziform load subdivided into columns . . . . . . . . . . . . . . . . . . . 232
13.3 Trapeziform load with a negative height . . . . . . . . . . . . . . . . . . . . 232
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13.4 Circular load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
13.5 Rectangular load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
14.1 Stress distribution under a point load . . . . . . . . . . . . . . . . . . . . . 237
14.2 Stress distribution under a load column . . . . . . . . . . . . . . . . . . . . 238
14.3 Stress distribution under a circular load . . . . . . . . . . . . . . . . . . . . 239
14.4 Stress distribution under a rectangular load . . . . . . . . . . . . . . . . . . 240
14.5 Imaginary surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
15.1 Pore pressure as a result of piezometric level lines . . . . . . . . . . . . . . 243
15.2 Theoretical and average pressure distribution between two drains . . . . . . . 250
15.3 Pressure distribution along a line-shaped drain (radial flow) . . . . . . . . . . 251
15.4 Pressure distribution along a plane-shaped drain (plane flow) . . . . . . . . . 252
16.1 NEN-Bjerrum: Idealized primary and secondary settlement during time (drained
conditions) ..................................256
16.2 NEN-Bjerrum: Idealized primary settlement during loading (drained conditions) 256
16.3 NEN-Bjerrum: Creep rate depending on overconsolidation . . . . . . . . . . 258
16.4 Height related to linear and natural strain . . . . . . . . . . . . . . . . . . . 259
16.5 Compressed height compression as a function of effective stress . . . . . . . 260
16.6 Creep Isotache pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
16.7 Koppejan settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
17.1 Over-consolidation: POP and OCR . . . . . . . . . . . . . . . . . . . . . . 266
17.2 Determining the common coefficient of secondary compression . . . . . . . . 267
17.3 Determining the Isotache natural secondary compression index c. . . . . . . 269
17.4 Determining Koppejan’s secondary compression index . . . . . . . . . . . . 270
18.1 FORM method ................................282
18.2 Situations considered by De Leeuw method . . . . . . . . . . . . . . . . . . 283
18.3 Non-uniform load schematized as a uniform load . . . . . . . . . . . . . . . 283
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List of Tables
2.1 Keyboard shortcuts for D-Settlement . . . . . . . . . . . . . . . . . . . . . 19
4.1 Predefined materials in D-Settlement . . . . . . . . . . . . . . . . . . . . . 48
8.1 Soil type properties (Tutorial 1) . . . . . . . . . . . . . . . . . . . . . . . . 128
9.1 Sand properties (Tutorial 2) . . . . . . . . . . . . . . . . . . . . . . . . . . 151
9.2 Peat properties (Tutorial 2) . . . . . . . . . . . . . . . . . . . . . . . . . . 151
9.3 Clay properties (Tutorial 2) . . . . . . . . . . . . . . . . . . . . . . . . . . 151
10.1 Co-ordinates of the different loading stages (Tutorial 3) . . . . . . . . . . . . 186
11.1 Soil type properties (Tutorial 4) . . . . . . . . . . . . . . . . . . . . . . . . 200
12.1 Soil properties from K0-CRS test (Tutorial 5) . . . . . . . . . . . . . . . . . 219
15.1 Comparison of Terzaghi and Darcy models in D-SETTLEMENT . . . . . . . . 254
17.1 Rough Isotache parameter correlation for soft soil types . . . . . . . . . . . . 269
18.1 E-modulus vs. unit weight (De Leeuw & Timmermans) . . . . . . . . . . . . 284
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1 General Information
1.1 Foreword
This is the user manual for
D-SETTLEMENT
, which is being developed by Deltares Systems,
a Deltares company.
D-SETTLEMENT
is a dedicated tool for predicting soil settlements by ex-
ternal loading.
D-SETTLEMENT
accurately and quickly determines the direct settlement, con-
solidation and creep along verticals in two-dimensional geometry. Deltares has been devel-
oping
D-SETTLEMENT
since 1992. Sponsorship from the Dutch Ministry of Transport, Pub-
lic Works and Water Management (Rijkswaterstaat) and Senter/EZ (the latter through Delft
Cluster projects and the GeoSafe project) has been vital for most model development and
validation.
Easy and efficient
D-SETTLEMENT
has proved itself to be a powerful tool in the everyday engineering practice of
making settlement calculations.
D-SETTLEMENT
s graphical user interface allows both frequent
and infrequent
D-SETTLEMENT
users to analyze regular settlement problems extremely quickly.
Complete functionality
D-SETTLEMENT
provides a complete functionality for determining settlements for regular two-
dimensional problems. Well-established and advanced models can be used to calculate
primary settlement/swelling, consolidation and secondary creep, with possible influence of
vertical drains. Different kinds of external loads can be applied: non-uniform, trapezoidal,
circular, rectangular, uniform and water loads. Vertical drains (strips and planes) with option-
ally enforced consolidation by temporary dewatering or vacuum consolidation can be mod-
eled.
D-SETTLEMENT
creates a comprehensive tabular and graphical output with settlements,
stresses and pore pressures at the verticals that have to be defined. An automatic fit on
measured settlements can be applied, in order to determine improved estimates of the final
settlement. Finally, the bandwidth and parameter sensitivity for total and residual settlements
can be determined, including the effect of measurements.
Product integration
D-SETTLEMENT
is an integrated component of the Deltares Tools. Therefore,
D-SETTLEMENT
s
soil parameters can be directly determined from test results by using MCompress. Fur-
thermore relevant data can be exchanged with MGeobase (central project database) and
D-GEO STABILITY
(stability analysis) formerly known as MStab. MGeobase is used to cre-
ate and maintain a central project database, containing data on the measurements, geom-
etry and soil properties of several cross-sections. MGeobase can also be used to exe-
cute series of
D-SETTLEMENT
analyses along a location line. Besides the exchange of in-
put data,
D-SETTLEMENT
can also export the settled geometry and excess pore pressures to
D-GEO STABILITY
for stability analysis.
1.2 Features in standard module
D-SETTLEMENT
was developed especially for geotechnical engineers.
D-SETTLEMENT
s graph-
ical interactive interface requires just a short training period for novice users. This means
that you can focus your skills directly on the input of sound geotechnical data and on the
subsequent settlement calculation.
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1.2.1 Soil profile
Multiple layers
The two-dimensional soil structure can be composed of several soil layers with an arbitrary
shape and orientation. Each layer is connected to a particular soil type.
Verticals
By placing verticals in the geometry, you can define the co-ordinates for which output re-
sults will be shown. The position of the z co-ordinate is only relevant for circular or rectan-
gular loads.
Soil properties
The well-established constitutive models are based on common soil parameters for virgin
compression, unloading/reloading and secondary creep. Parameters of the different mod-
els can also be determined directly from the results of oedometer tests, using the MCom-
press program. Consolidation is either modeled by means of a consolidation coefficient or
by means of permeability per layer.
1.2.2 Loads
Subsequent loads at different times can be applied. Initial loads will not cause consolidation
or secondary creep. Stress distribution is taken into account, also in the soil weight loads.
Soil weight loads
Soil weight loads with uniform, trapezoidal and non-uniform shape of the soil cross-section
can be applied.
D-SETTLEMENT
can include an additional, deformation dependent load.
This load is equal to the soil that must be added to maintain the defined top surface po-
sition.
D-SETTLEMENT
can take account of the settlement-dependent weight reduction by
submerging. Embankment construction loading can be generated from simplified input, or
from imported measured surface positions.
Distributed loads
Distributed loads with a circular or rectangular base can be applied.
Water loads
Changes in pore pressure distributions at different times can be defined.
1.2.3 Models
There are three constitutive models available in
D-SETTLEMENT
: NEN-Bjerrum, NEN-Koppejan
and Isotache.
NEN-Bjerrum Cr/Cc/Ca
The NEN-Bjerrum model supports today’s international de-facto standard for settlement
predictions, as contained for example in the Dutch standard NEN 6744-1:1991 (NEN,
1991b). The model uses common linear strain soil parameters (Cc,Cr,Cα). Lin-
ear strains are referred to the undeformed state, presuming that strains are sufficiently
small. The theoretical basis of the underlying creep rate description is the isotache
model, and often associated with the name Bjerrum (1972).
Isotache a/b/c
The Isotache a/b/c model by Den Haan (1994) enhances the NEN-Bjerrum model by
using a so-called natural strain, which is referred to the deformed state. Usage of natural
strain is expected to yield more realistic settlement curves in cases with large strains.
The special natural strain parameters are furthermore more objective with respect to
the stress and strain level.
NEN-Koppejan
Compared to the NEN-Bjerrum model, the traditional NEN-Koppejan model assumes
an instantaneous contribution by primary settlement and is not capable of describing
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General Information
unloading/reloading behavior. Furthermore, NEN-Koppejan uses different parameter
definitions and assumes that secondary settlement is stress-dependent. The user can
opt for a linear or natural strain assumption.
All three constitutive models can be combined with the Terzaghi or Darcy consolidation model.
Both consolidation models are suited for all modern drainage systems. They support different
types of vertical drains (strips, columns and screens), with optional enforced dewatering. For
both models the influence of consolidation can be combined with user-defined piezometric
levels defining the hydraulic field, optionally layer by layer and time-dependent.
Darcy
Darcy’s general storage equation can be used for accurate determination of the in-
fluence of excess pore pressures on settlements of combined soil layers. The Darcy
method calculates the excess pore pressure distributions at different time points and
derives the deformation during consolidation from the development of the true effec-
tive stress. The Darcy model in combination with the isotache models also allows for
modelling the gradual decrease of effective weight during submerging of loading and
layers.
Terzaghi
Terzaghi’s one-dimensional theoretical solution for consolidation of elastic soil can be
used to modify the drained settlement solution, in order to approximate the influence
of excess pore pressure generation (Terzaghi and Peck,1967). The combination with
vertical drains can be considered as an extension to the Terzaghi-Barron-Carillo method
(Barron,1948;Carillo,1942).
1.2.4 Results
Following the analysis,
D-SETTLEMENT
can display results in tabular and graphical form.
The tabular report contains an echo of the input data and both settlements and stresses
per vertical.
Settlements and stress components can be viewed graphically in time and along depth.
A dissipation design graph can be viewed, showing the degree of consolidation by uni-
form loading for each layer.
The settled geometry can be viewed or written to a geometry file.
Finally, the settled geometry and excess pore pressures for a stability analysis with the
D-GEO STABILITY
program can also be written.
1.3 Features in additional modules
1.3.1 Fits on settlement plate measurements
Measured settlements can be imported and used by
D-SETTLEMENT
to perform fits by auto-
matic scaling of material parameters. This feature enables a more accurate estimate of the
final and residual settlement.
1.3.2 Reliability analysis
A reliability analysis is available to determine the bandwidth and parameter sensitivity for total
and residual settlements, including the increased reliability after a preliminary settlement plate
fit.
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1.3.3 Horizontal displacements
Horizontal displacements can be calculated according to De Leeuw tables (De Leeuw,1963)
1.4 History
D-SETTLEMENT
(formerly known as MSettle until version 8.2) has been developed by Deltares/
GeoDelft. Version 1.0 was first released in 1992 under the name of MZet. A simplified NEN-
Bjerrum calculation method with limited applicability was added in 1993. Some new features,
such as the option to save a settled geometry, were added in 1994. In 1995, the Koppejan
method was adapted to allow loads to be added at different points in time. Version 4.0 (1998)
was the first Windows version of MZet. Its name was then changed to MSettle. In 1999 a first
version of the a/b/c Isotache model was incorporated into MSettle Version 5.0.
Version 6.0 (2001) included an enhanced module for geometrical modelling, and improved
versions of the user manual and on-line Help have been released.
Version 6.7 (2002) was the first modular release of MSettle, meaning that different modules
can be purchased separately. The 6.7 version included separate 1D and 2D modules, sim-
plified input of embankment construction by load generation, several improvements to the
isotache model and its documentation, a choice between the Terzaghi and Darcy consolida-
tion models, vertical drains (only for the Darcy model), and user-controlled variation of soil
parameters in order to fit settlement plate curves.
Version 6.8 (2003) included a completely new formulation of the NEN-Bjerrum model and an
enhanced report format. The new NEN-Bjerrum model still uses the common soil parameters
Cc,Cr,Cα, but is now based on the same isotache formulation as the a/b/c/ model. The new
formulation is therefore also suited for loading stages and un-/reloading sequences, which
were not possible with the old formulation.
Version 7.1 (2004) featured the new combination of vertical drains with the Terzaghi consol-
idation model, coupled stability analysis with MStab and a new design graph for the degree
of consolidation. Furthermore the chart data behind all graphs had been made available, for
usage in spread sheets et cetera.
Version 7.3 (2006) offers an automatic settlement plate fit. It also includes the new reliability
module. Furthermore, input of temporary loading has been simplified, the plot of transient
settlements has been extended with a plot of the loading and the Material window has been
redesigned.
The settlement plate fit is now part of the Calculation menu (section 5.3). The usage of
the manual fit has been simplified, and a robust automatic fit has been added. The Use Fit
parameters option (section 5.4) is available to generate modified results from a complete
settlement analysis. Reading of measurement data is now also supported from files with
tab delimited format (TXT), or comma (;) delimited format (CSV).
An evaluation version of the Reliability module has been added (section 5.4.2). This mod-
ule offers different methods to determine the bandwidth of the predicted settlements.
A graph of loading versus time has been attached to the graph of settlement versus time
(section 6.5,section 6.5.2).
Input of temporary loading has been simplified by the introduction of an end time for non-
uniform loading (section 4.6.1).
A graph of residual settlements versus different start times has been made available (sec-
tion 6.7).
The Material window (section 4.2) was redesigned, in order to separate the parameters
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General Information
for the soil model from the parameters for the consolidation model. An equivalent age
indication of over-consolidation was added to the NEN-Bjerrum and Isotache models.
Version 8.2 was released in 2009. This version includes the following improvements and new
features:
The Darcy consolidation model has been strongly improved and is now the default consol-
idation model:
It is more accurate than the Terzaghi model;
It uses the same input as the Terzaghi model. This means that Darcy is now based on
excess pore pressures instead of total pore pressures, and that direct input of the consoli-
dation coefficient is allowed.
It consumes considerable less computation time than in the previous version, and features
a significantly increased robustness. The latter means that previous numerical problems
by spatial oscillations and by negative effective stresses are practically vanished.
Deformation of drained layers is now included.
Submerging modelling has been improved in combination with the Isotache and NEN-
Bjerrum models: the effective weight of both non-uniform loads and soil layers changes
gradually during submerging, by taken into account the actual settlement instead of the
final settlement. See section 1.5.1 for a comparison between the new Darcy model and the
Terzaghi model.
Optional direct input of the Preconsolidation pressure in the Material window is available
for the Isotache and NEN-Bjerrum models (section 4.2.4,section 4.2.5), in order to model
special cases where a definition via POP or OCR is not sufficient.
Vertical drains can be limited to a certain horizontal range. Furthermore the input has been
simplified, both by introducing dedicated input for different drain types (strips, columns,
sand screens) and dewatering methods and by supplying common defaults for applicable
input parameters (section 4.4.2).
The system for error messages and warnings has been improved, as well as the messages
themselves (section 6.2.7).
Output of report and plots are now available in the English, French and Dutch languages
(section 3.2.4).
Result graphs have been extended. With the Darcy model, MSettle gives results for dif-
ferent stress components in time and along the depth. With the Terzaghi model, the
settlement-depth curve has been added (section 6.5,section 6.6).
The Reliability module (section 18.2) is upgraded from evaluation version to product ver-
sion, including full verification.
The Horizontal Displacement module (section 18.3) based on De Leeuw tables (De Leeuw,
1963) has been added.
Version 9.1 was released in 2011. The name of the program is changed to
D-SETTLEMENT
.
Version 9.3 was released in 2012. This version includes the following improvements and new
features:
Know issues are solved.
Calculated horizontal displacements can be found in the report.
For other calculations than NEN-Koppejan, the given pre-consolidation stress is taken into
account too.
When using Other Loads it is possible to add a storage tank (section 4.6.3).
Version 14.1 (July 2014). This version implements only the improvements on the changes in
the new licensing scheme.
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Version 15.1 (April 2015). This version implements some improvements in the calculation:
The combination Water Loads and Submerging didn’t worked properly when the maxi-
mum iteration steps for submerging was more than 1. This is now fixed.
The combination Koppejan-Darcy could lead to an error (“Error occurred during compu-
tation of excess head”). This is now fixed.
In the report for combination Koppejan-Terzaghi, the primary and secondary settle-
ments per layer were not always calculated if the number of layers differed from the
number of materials. This is now fixed.
For Koppejan model, the pre-consolidation stress σpwas used only when this parame-
ter was set for the Isotache model. This is now fixed.
This version also implements some improvements in the user interface:
In the Vertical Drains window, the sub-window Enforced Dewatering is renamed into
Drainage schedule
A toggle button is implemented in the View Input (Figure 2.5), to switch between same
scale for X and Y-axis and not same scale for X and Y-axis.
The Help file is no more available; clicking on the Help button will open the User Manual
in which a search by specific word can be performed.
Version 16.1 (January 2016). With this version, license(s) can be borrowed for a certain
period allowing working without connection to the licence server (see section 3.2.5 for more
information). This version also contains solved issues (for a complete list, download the Re-
lease Notes from the Download Portal of Deltares).
1.5 Limitations
When working with
D-SETTLEMENT
, the following limitations apply.
During vertical displacements calculation,
D-SETTLEMENT
assumes that horizontal dis-
placements are zero. The horizontal displacements from the corresponding module will
therefore not influence the vertical displacements calculation.
For Terzaghi, the submerged weight is determined on the basis of final settlements.
Furthermore, only the weight of non-uniform loads is reduced, e.g. not the weight of
uniform loads or soil layers.
For Darcy, the gradually changing submerged weight during the calculation is only cal-
culated for non-uniform loads and soil layers, but not for uniform loads.
The consolidation models do not explicitly describe horizontal flow. The horizontal flow
to drains is modelled by a leakage term.
The Terzaghi model does not calculate the actual effective pressures during consolida-
tion, but is based on an approximate adjustment of settlements from a drained solution,
see section 1.5.1.
Both options Fit for Settlement Plate and Submerging do not work in combination, for
the none-accurate Submerging method (section 1.5.1). When a plate fit is performed,
the Submerging option is not taken into account. When a normal calculation is done
using fit parameters in combination with the Submerging option, the results differ from
those displayed in the Fit for Settlement Plate chart. This limitation applies only for the
none-accurate submerging method. For the accurate method (i.e Darcy+Isotache and
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General Information
Darcy+Bjerrum), Submerging is taken into account during the Fit for Settlement Plate
calculation.
1.5.1 Darcy vs. Terzaghi
The Darcy model uses a step-wise accurate numerical solution of effective stress and pore
pressure at different points in time and space. The Terzaghi model uses a time-dependent
"degree of consolidation" according to the Terzaghi theory (Terzaghi and Peck,1967), to adjust
the drained settlement solution approximately for the effect of consolidation.
The Terzaghi model has a number of limitations, compared to the Darcy model.
The settlement after completed consolidation with the Terzaghi model will always be
equal to the settlement from a drained solution, even if unloading took place shortly
after preceding loading.
For the same reason, the updated pre-consolidation stress during reloading will be
overestimated with Terzaghi if unloading took place before consolidation was finished.
The combination of layers with different consolidation coefficients and the combination
with vertical drains are also described more accurately with Darcy.
The period of consolidation with Terzaghi will be equal during loading and un/reloading,
while Darcy will show faster consolidation during un/reloading.
The influence of vertical drains and dewatering is averaged along a full layer in com-
bination with Terzaghi. This limitation is especially important for the layer in which the
vertical drain ends.
The Terzaghi model describes submerging by an initial load reduction (i.e. non–accurate
method), while the Darcy model in combination with the NEN-Bjerrum or Isotache model
takes into account the gradual character of it (i.e. accurate method).
Compared to the previous Darcy model, the Darcy model in version 8.2 consumes consider-
able less computation time than in the previous version, supports the same input as the Terza-
ghi model, features improved submerging modelling and a significantly increased robustness.
A choice for the Darcy model is since release 8.2 recommended under most circumstances,
as it combines the advantages of the Terzaghi model (fast, robust, convenient input) with
improved accuracy.
1.5.2 NEN-Koppejan vs. NEN-Bjerrum/Isotache
The NEN-Koppejan model has been the traditional choice in the Netherlands for many years.
The applicability of the Koppejan model is however limited, as it has not been designed
to predict unloading/reloading. The Dutch geotechnical design codes currently prescribe a
Cc/Cr/Cαmethod, just as other countries do.
D-SETTLEMENT
s isotache models with Cc/Cr/Cα
or a/b/c parameters are capable of modelling both incremental loading and unloading/reloading.
The other difference is that Koppejan assumes a stress dependent slope of the creep tail af-
ter virgin loading whereas the Cc/Cr/Cαmodel assumes that the slope after virgin loading is
stress independent.
Key concept of both isotache models is a direct relationship between overconsolidation, creep
rate and equivalent age. The only difference between these models is the usage of linear
strain for the Cc/Cr/Cαmodel and natural strain for the a/b/c model.
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1.6 Minimum System Requirements
The following minimum system requirements are needed in order to run and install the Deltares
software, either from CD or by downloading from the Deltares Systems website via MS Inter-
net Explorer.
Operating systems:
Windows 2003,
Windows Vista,
Windows 7 – 32 bits
Windows 7 – 64 bits
Windows 8
Hardware specifications:
1 GHz Intel Pentium processor or equivalent
512 MB of RAM
400 MB free hard disk space
SVGA video card, 1024 ×768 pixels, High colors (16 bits)
CD-ROM drive
Microsoft Internet Explorer version 6.0 or newer (download from www.microsoft.com)
1.7 Definitions and Symbols
nPorosity
e0Initial void ratio:
e0=n0
1n0
cvVertical coefficient of consolidation, one-dimensional
σ0Effective vertical soil pressure
σpPreconsolidation pressure (maximum vertical effective pressure experienced
in the past)
σ0Initial vertical effective soil pressure
POP Pre-overburden pressure: P OP =σpσ0
0
OCR Overconsolidation ratio:
OCR =σp
σ0
0
tTime in days
H0Vertical height of layer or oedometer sample at the start of (un)loading
htVertical height of layer or oedometer sample at time t after (un)loading
HVertical settlement of layer or sample at time t:H=htH0
εCEngineering vertical strain (Cauchy):
εc=h
h0
εHNatural vertical strain (Hencky):
εH=ln h0h
h0=ln (1 εc)
˙εStrain rate:
˙ε=
dt
Csw Primary swelling index (unloading):
Csw = (1 + e0)
dlog σ0with σ0< σp
CcPrimary compression index (virgin loading):
Cc= (1 + e0)
dlog σ0with σ0> σp
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General Information
CαCoefficient of secondary compression (strain based):
Cα=
dlog t
a(Isotache) Modified natural swelling index:
a=Csw|εH
(1 + e0) ln 10
b(Isotache) Modified natural compression index:
b=Cc|εH
(1 + e0) ln 10
c(Isotache) Modified natural secondary compression constant:
c=Cα|εH
ln 10
tage Initial equivalent age:
Isotache: tage =τ0×OCR
ba
c
NEN-Bjerrum: tage =τ0×OCR
CR RR
Cα
τ0Creep rate reference time
Cr(NEN-Bjerrum) Reloading/Swelling index:
Cr=Csw|εC
CR (NEN-Bjerrum) Compression ratio:
CR =Cc|εC
1 + e0
RR (NEN-Bjerrum) Reloading/Swelling ratio:
RR =Cr|εC
1 + e0
Cp(NEN-Koppejan) Primary compression coefficient below pre-consolidation:
Cp(1 + e0) ln 10
Csw
with σ0< σp
Cp (NEN-Koppejan) Primary compression coefficient above pre-consolidation:
C0
p(1 + e0) ln 10
Cc
with σ0> σp
Cs(NEN-Koppejan) Secular compression coefficient below pre-consolidation:
Secular compression coefficient (Cs)
Cs= ln σ0
σ0d log t
dεwith σ0< σp
Cs (NEN-Koppejan) Secular compression coefficient above pre-consolidation:
C0
s= ln σ0
σpd log t
dεwith σ0> σp
Ap(NEN-Koppejan) Primary swelling coefficient:
Ap=(1 + e0) ln 10
Csw
with σ0< σ0
0
As(NEN-Koppejan) Secondary swelling coefficient:
As= ln σ0
σ0
0dlog t
with σ0< σ0
0
γUnit weight
ϕWater head
kh,kvDarcy permeability in horizontal and vertical direction
CkThe constant for strain dependent permeability
KwBulk modulus of water
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1.8 Getting Help
From the Help menu, choose the Manual option to open the User Manual of
D-SETTLEMENT
in PDF format. Here help on a specific topic can be found by entering a specific word in the
Find field of the PDF reader.
1.9 Getting Support
Deltares Systems tools are supported by Deltares. A group of 70 people in software develop-
ment ensures continuous research and development. Support is provided by the developers
and if necessary by the appropriate Deltares experts. These experts can provide consultancy
backup as well.
If problems are encountered, the first step should be to consult the online Help at
www.deltaressystems.com menu ‘Software’. Different information about the program can be
found on the left-hand side of the window (Figure 1.1):
In ‘Support - Frequently asked questions’ are listed the most frequently asked technical
questions and their answers.
In ‘Support - Known issues’ are listed the bugs of the program.
In ‘Release notes’ are listed the differences between an old and a new version.
Figure 1.1: Deltares Systems website (www.deltaressystems.com)
If the solution cannot be found there, then the problem description can be e-mailed (preferred)
or faxed to the Deltares Systems Support team. When sending a problem description, please
add a full description of the working environment. To do this conveniently:
Open the program.
If possible, open a project that can illustrate the question.
Choose the Support option in the Help menu. The System Info tab contains all relevant
information about the system and the Deltares Systems geo-software. The Problem De-
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General Information
scription tab enables a description of the problem encountered to be added.
Figure 1.2: Support window, Problem Description tab
After clicking on the Send button, the Send Support E-Mail window opens, allowing sending
current file as an attachment. Marked or not the Attach current file to mail checkbox and
click OK to send it.
Figure 1.3: Send Support E-Mail window
The problem report can either be saved to a file or sent to a printer or PC fax. The document
can be emailed to support@deltaressystems.nl or alternatively faxed to +31(0)88 335 81 11.
1.10 Deltares
Since its foundation in 1934, GeoDelft has been one of the first and most renowned geotech-
nical engineering institutes of the world. On January 1st 2008, GeoDelft has merged with WL
|Delft Hydraulics and some parts of Rijkswaterstaat and TNO into the new Deltares Institute on
delta technology. Part of Deltares’s role is still to obtain, generate and disseminate geotechni-
cal know-how. For more information on Deltares, visit the Deltares website: www.deltares.nl.
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1.11 Deltares Systems
Deltares Systems is a Deltares company. The company’s objective is to convert Deltares’s
knowledge into practical geo-engineering services and software. Deltares Systems has de-
veloped a suite of software for geotechnical engineering. Besides software, Deltares Systems
is involved in providing services such as hosting online monitoring platforms, hosting on-line
delivery of site investigation, laboratory test results, etc. As part of this process Delft GeoSys-
tems is progressively connecting these services to their software. This allows for more stan-
dardized use of information, and the interpretation and comparison of results. Most software
is used as design software, following design standards. This however, does not guarantee
a design that can be executed successfully in practice, so automated back-analyses using
monitoring information are an important aspect in improving geotechnical engineering results.
Deltares Systems makes use of Deltares’s intensive engagement in R&D for GeoBrain. Geo-
Brain’s objective is to combine experience, expertise and numerical results into one forecast,
using Artificial Intelligence, Neural Networks and Bayesian Belief Networks. For more infor-
mation about Deltares GeoSystems’ geotechnical software, including download options, visit
www.deltaressystems.com or choose the Deltares Systems Website option from the Help
menu of
D-SETTLEMENT
.
1.12 Acknowledgements
The former Road and Hydraulic Engineering Division (Rijkswaterstaat/DWW) of the Dutch
Ministry of Transport, Public Works and Water Management has sponsored the first develop-
ment of
D-SETTLEMENT
.
The contribution from the EZ/Senter project GeoSafe on the reliability framework and the
many contributions from the research program Delft Cluster are also gratefully acknowledged.
These contributions were crucial for developing and evaluating the present set of well-established
models.
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2 Getting Started
This Getting Started chapter aims to familiarize the user with the structure and user inter-
face of
D-SETTLEMENT
. The Tutorial section which follows uses a selection of case studies to
introduce the program’s functions.
2.1 Starting D-Settlement
To start
D-SETTLEMENT
, click Start on the Windows taskbar or double-click a
D-SETTLEMENT
input file that was generated during a previous session.
For a
D-SETTLEMENT
installation based on floating licenses, the ModulesModules window may
appear at start-up (Figure 2.1). Check that the correct modules are selected and click OK.
Figure 2.1: Modules window
When
D-SETTLEMENT
is started from the Windows taskbar, the last project that was worked
on will open automatically (unless the program has been configured otherwise in the Pro-
gram Options window, reached from the Tools menu) and
D-SETTLEMENT
will display the main
window (section 2.2).
2.2 Main Window
When
D-SETTLEMENT
is started, the main window is displayed (Figure 2.2). This window
contains a menu bar (section 2.2.1), an icon bar (section 2.2.2), a View Input window (sec-
tion 2.2.3) that displays the pre-selected or most recently accessed project, a title panel (sec-
tion 2.2.4) and a status bar (section 2.2.5). The caption of the main window of
D-SETTLEMENT
displays the program name, followed by the calculation model, the consolidation model and
the strain type. When a new file is created, the default calculation model is NEN-Bjerrum
(Linear strain), the default consolidation model is Darcy and the project name is Project1.
The first time after installation of
D-SETTLEMENT
, the View Input window will be closed. Main
window
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Figure 2.2: D-Settlement main window
2.2.1 The menu bar
To access the
D-SETTLEMENT
menus, click the names on the menu bar.
Figure 2.3: D-Settlement menu bar
The menus contain the following functions:
File Standard Windows options for opening, saving and sending files as well
as several
D-SETTLEMENT
options for exporting and printing active win-
dows and reports (section 3.1).
Project Options for selecting the model types, defining project properties and
viewing the input file (section 4.1).
Soil Options for defining the soil type properties (section 4.2).
Geometry Options for defining layers boundaries, soil types and piezometric lines
(section 4.3).
GeoObjects Options for defining the verticals (X co-ordinates) for which results will
be shown, the vertical drains and the pore pressure meters (section 4.4).
Water Input of water parameters (section 4.5).
Loads Input of external loads (section 4.6).
Calculation A wide range of calculation options to determine the settlements and
stresses along the verticals (chapter 5).
Results Options for displaying graphical or tabular output of the settlements and
stresses per vertical (chapter 6).
Tools Options for editing
D-SETTLEMENT
program defaults (section 3.2).
Window Default Windows options for arranging the
D-SETTLEMENT
windows and
choosing the active window.
Help Online Help (section 2.1).
14 of 290 Deltares
Getting Started
2.2.2 The icon bar
Use the buttons on the icon bar to quickly access frequently used functions (see below).
Figure 2.4: D-Settlement icon bar
Click on the following buttons to activate the corresponding functions:
Start a new
D-SETTLEMENT
project.
Open the input file of an existing project.
Save the input file of the current project.
Print the contents of the active window.
Display a print preview.
Open the Project Properties window. Here you can enter the project title and
other identification data, and determine the View Layout and Graph Settings for
your project.
Start the calculation.
Display the contents of online Help.
2.2.3 View Input window
The View Input window displays the geometry and additional
D-SETTLEMENT
input of the cur-
rent project. The window has the following three tabs:
Geometry
In this view it is possible to define, inspect and modify the positions and soil types
of different layers. For more information about these general options for geometrical
modelling, see the description of the Geometry menu (section 4.3) or see section 7.4.
Input
In this view it is possible to define, inspect and modify the additional
D-SETTLEMENT
spe-
cific input. For more information on the available options, see below in this paragraph.
Top View
This tab shows the lateral and the top view of the inputted project.
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Figure 2.5: View Input window, Input tab
Figure 2.6: View Input window, Top View tab
The panel on the left of the view contains buttons for entering data and controlling the graph-
ical view. Click on the following buttons in the Edit,Tools or Stage panel to activate the
corresponding functions:
Select and Edit mode
In this mode, the left-hand mouse button can be used to graphically select a previ-
ously defined grid, load, geotextile or forbidden line. Items can then be deleted or
modified by dragging or resizing, or by clicking the right-hand mouse button and
choosing an option from the menu displayed. Pressing the Escape key will return
the user to this Select and Edit mode.
Add point(s) to boundary / PL-line
Click this button to add points to all types of lines (lines, polylines, boundary lines,
PL-lines). By adding a point to a line, the existing line is split into two new lines.
This provides more freedom when modifying the geometry.
16 of 290 Deltares
Getting Started
Add single line(s)
Click this button to add single lines. When this button is selected, the first left-hand
mouse click will add the info bar of the new line and a “rubber band” is displayed
when the mouse is moved. The second left-hand mouse click defines the end
point (and thus the final position) of the line. It is now possible to either go on
clicking start and end points to define lines, or stop adding lines by selecting one
of the other tool buttons, or by clicking the right-hand mouse button, or by pressing
the Escape key.
Add polyline(s)
Click this button to add polylines. When this button is selected, the first left-hand
mouse click adds the starting point of the new line and a “rubber band” is displayed
when the mouse is moved. A second left-hand mouse click defines the end point
(and thus the final position) of the first line in the polyline and activates the “rubber
band” for the second line in the polyline. Every subsequent left-hand mouse click
again defines a new end point of the next line in the polyline. It is possible to end
a polyline by selecting one of the other tool buttons, or by clicking the right-hand
mouse button, or by pressing the Escape key.
Add PL-line(s)
Click this button to add a piezometric level line (PL-line). Each PL-line must start
at the left limit and end at the right limit. Furthermore, each consecutive point must
have a strictly increasing X co-ordinate. Therefore, a PL-line must be defined from
left to right, starting at the left limit and ending at the right limit. To enforce this,
the program will always relocate the first point clicked (left-hand mouse button) to
the left limit by moving it horizontally to this limit. If trying to define a point to the
left of the previous point, the rubber band icon indicates that this is not possible.
Subsequently clicking on the left side of the previous point, the new point will be
added at the end of the rubber band icon instead of the position clicked.
Pan
Click this button to change the visible part of the drawing by clicking and dragging
the mouse.
Zoom in
Click this button to enlarge the drawing, and then click the part of the drawing
which is to be at the centre of the new image. Repeat if necessary.
Zoom out
Click this button, and then click on the drawing to reduce the drawing size. Repeat
if necessary.
Zoom rectangle
Click this button then click and drag a rectangle over the area to be enlarged. The
selected area will be enlarged to fit the window. Repeat if necessary.
Add vertical
Click this button to graphically define the position of a vertical.
Add non-uniform load
Click this button to display a window in which it is possible to add, modify or delete
non-uniform loads per unit of area.
Add other load
Click this button to display a window in which it is possible to add, modify or delete
trapezoidal, circular, rectangular or uniform loads.
Convert geometry to 1D
Click this button to convert geometry to 1D.
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Measure the distance and slope between two points
Click this button, then click the first point on the View Input window and place the
cross on the second point. The distance and the slope between the two points
can be read beside the second point. To turn this option off, click the escape key.
Undo zoom
Click this button to undo the zoom. If necessary, click several times to retrace
each consecutive zoom-in step that was made.
Zoom limits
Click this button to display the complete drawing.
Same scale for X and Y axis
Click this button to use the same scale for the horizontal and vertical directions.
Automatic regeneration of geometry on/off
When selected, the program will automatically try to generate a new valid geom-
etry whenever geometry modifications require this. During generation, (poly)lines
(solid blue) are converted to boundaries (solid black), with interjacent layers. New
layers receive a default material type. Existing layers keep the materials that were
assigned to them. Invalid geometry parts are converted to construction elements.
Automatic regeneration may slow down progress during input of complex geome-
try, because validity will be checked continuously.
Redo
Click this button to redo the previous Undo action
Undo
Click this button to undo the last change(s) made to the geometry
Delete
Click this button to delete a selected element.
NOTE: This button is only available when an element is selected.
Previous stage
Click this button to view the previous stage in the sequence of loading.
Next stage
Click this button to view the next stage in the sequence of loading.
2.2.4 Title panel
This panel situated at the bottom of the View Input window displays the project titles, as
entered on the Identification tab in the Project Properties window (section 4.1.3).
2.2.5 Status bar
This bar situated at the bottom of the main window displays a description of the selected icon
of the icon bar (section 2.2.2).
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Getting Started
2.3 Files
*.sli Input file (ASCII):
Contains all specific input for
D-SETTLEMENT
. After interactive generation, this file
can be reused in subsequent
D-SETTLEMENT
analyses.
*.sls Setting file (ASCII):
Working file with settings data. This file doesn’t contain any information that is
relevant for the calculation, but only settings that apply to the representation of
the data, such as the grid size.
*.geo Input file (ASCII):
Contains the (deformed) geometry data that can be shared with other Deltares
Geo-programs.
*.sti Output file (ASCII):
File used by
D-SETTLEMENT
for a coupled stability analysis, with deformed geom-
etry and excess pore pressures.
*.sld Dump file (ASCII):
Contains calculation results used for graphical and report output.
*.slo Obsolete file (ASCII):
Contains echo of input and tabular results.
*.err Error file (ASCII):
If there are any errors in the input, they are described in this file.
*.gef Geotechnical Exchange Format file (ASCII):
Contains measurements data. GEF file
*.slm SLM file (ASCII):
Input of settlement and surface measurements.SLM file
2.4 Tips and Tricks
2.4.1 Keyboard shortcuts
Use the keyboard shortcuts given in Table 2.1 to directly opening a window without selecting
the option from the bar menu.
Table 2.1: Keyboard shortcuts for D-Settlement
Keyboard shortcut Opened window
Ctrl + N New
Ctrl + S Save
Ctrl + O Open
F12 Save As
Ctrl + C Copy Active Window to Clipboard
Ctrl + P Print Report
Ctrl + M Model
Ctrl + T Materials
Ctrl + E Verticals
F9 Start Calculation
Ctrl + R Report
2.4.2 Exporting figures and reports
All figures in
D-SETTLEMENT
such as geometry and graphical output can be exported in WMF
(Windows Meta Files) format. In the File menu, select the option Export Active Window to
save the figures in a file. This file can be later imported in a Word document for example
or added as annex in a report. The option Copy Active Window to Clipboard from the File
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menu can also be used to copy directly the figure in a Word document. The report can be
entirely exported as PDF (Portable Document Format) or RTF (Rich Text Format) file. To look
at a PDF file Adobe Reader can be used. A RTF file can be opened and edited with word
processors like MS Word. Before exporting the report, a selection of the relevant parts can be
done with the option Report Selection (section 6.1).
2.4.3 Copying part of a table
It is possible to copy part of a table in another document, an Excel sheet for example. If the
cursor is placed on the left-hand side of a cell of the table, the cursor changes in an arrow
which points from bottom left to top right. Select a specific area by using the mouse (see
Figure 2.7a). Then, using the copy button (or ctrl+C) this area can be copied.
a) b)
c) d)
Figure 2.7: Selection of different parts of a table using the arrow cursor
To select a row, click on the cell before the row number (see Figure 2.7b). To select a column,
click on the top cell of the column (see Figure 2.7c). To select the complete table, click on the
top left cell (see Figure 2.7d).
In some tables the option Copy is also present at the left hand pane.
2.4.4 Continuous display of the results in time or depth
In the Time-History and/or Depth-History windows, by selecting the first Time or Depth step
respectively at the top of the window and using the scroll button of the mouse, graphical results
are displayed in a continuous way in time (from initial to final time) or in depth (from ground
surface to the base).
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3 General
This part of the manual contains a detailed description of the available menu options for input,
calculation and viewing results.
The examples in the tutorial section provide a convenient starting point for familiarization with
the program.
3.1 File menu
Besides the familiar Windows options for opening and saving files, the File menu contains a
number of options specific to
D-SETTLEMENT
.
New
Select this option to display the New File window (Figure 3.1). Three choices are available
to create a new geometry:
Select New geometry to display the View Input window, showing only the geometry
limits (with their defaults values) of the geometry;
Select New geometry wizard to create a new geometry faster and easier using the
wizard option (involving a step-by-step process for creating a geometry, see sec-
tion 4.3.2);
Select Import geometry to use an existing geometry.
Figure 3.1: New File window
Copy Active Window to Clipboard
Use this option to copy the contents of the active window to the Windows clipboard so
that they can be pasted into another application. The contents will be pasted in either text
format or Windows Meta File format.
Export Active Window
Use this option to export the contents of the active window as a Windows Meta File (*.wmf),
a Drawing Exchange File (*.dxf) or a text file (*.txt). After clicking the Save button in the
Export to window, the Export complete window opens displaying three choices:
Open to open the file containing the exported window;
Open Folder to open the folder where the file was saved;
Close to close the Export complete window.
Export Report
This option allows the report to be exported in a different format, such as pdf or rtf.
Page Setup
This option allows definition of the way
D-SETTLEMENT
plots and reports are to be printed.
The printer, paper size, orientation and margins can be defined as well as whether and
where axes are required for plots. Click Autofit to get
D-SETTLEMENT
to choose the best fit
for the page.
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Print Preview Active Window
This option will display a print preview of the current contents of theView Input or Results
window.
Print Active Window
This option prints the current contents of the View Input or Results window.
Print Preview Report
This option will display a print preview of the calculation report.
Print Report
This option prints the calculation report.
3.2 Tools menu
On the menu bar, click Tools and then choose Program Options to open the corresponding
input window. In this window, the user can optionally define their own preferences for some of
the program’s default values through the following tabs:
section 3.2.1 View tab
section 3.2.2 General tab
section 3.2.3 Locations tab
section 3.2.4 Language tab
section 3.2.5 Modules tab
3.2.1 Program Options – View
Figure 3.2: Program Options window, View tab
Toolbar Mark this checkbox to display the icon bar (section 2.2.2) each time
D-SETTLEMENT
is started.
Status bar Mark this checkbox to display the status bar (section 2.2.5) each time
D-SETTLEMENT
is started.
Title panel Mark the checkbox to display the project titles, as entered on the Identifi-
cation tab in the Project Properties window, in a panel at the bottom of the
View Input window.
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General
3.2.2 Program Options – General
Figure 3.3: Program Options window, General tab
Start-up with Click one of these toggle buttons to determine whether a project should
be opened or initiated when the program is started.
No project: Each time
D-SETTLEMENT
is started, the buttons in the tool-
bar or the options in the File menu must be used to open an existing
project or to start a new one.
Last used project: Each time
D-SETTLEMENT
is started, the last project
that has been worked on is opened automatically.
New project: A new project is created. The user is offered three options
at the start up of
D-SETTLEMENT
:New geometry,New geometry wizard
and Import geometry.
NOTE: The Start-up with option is ignored when
D-SETTLEMENT
is
started by double-clicking on an input file.
Save on
Calculation
The toggle buttons determine how input data is saved prior to calcula-
tion. The input data can either be saved automatically, using the same
file name each time, or a file name can be specified each time the data
is saved.
Halt on
Warnings
Unmark this checkbox to prevent pausing the calculation in case of
warnings.
Use Enter key
to
Use the toggle buttons to determine the way the Enter key is used
in the program: either as an equivalent of pressing the default button
(Windows-style) or to shift the focus to the next item in a window (for
users accustomed to the DOS version(s) of the program).
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3.2.3 Program Options – Locations
Figure 3.4: Program Options window, Locations tab
Working
directory
D-SETTLEMENT
will start up with a working directory for selection and
saving of files. Either choose to use the last used directory, or specify a
fixed path.
MGeobase
database
Here it is possible to assign a database location. This database (*.gdb or
*.mdb) can be accessed with several options in
D-SETTLEMENT
to retrieve
D-SETTLEMENT
specific data from this file location.
3.2.4 Program Options – Language
Figure 3.5: Program Options window, Language tab
Select the language to be used in the
D-SETTLEMENT
windows and on printouts.
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General
Interface
language
Currently, the only available interface language is English.
Output
language
Three output languages are supported: English, French and Dutch. The
selected output language will be used in all exported reports and graphs.
3.2.5 Program Options – Modules
For a
D-SETTLEMENT
installation based on floating licenses, the Modules tab can be used to
claim a license for the particular modules that are to be used. If the Show at start of program
checkbox is marked then this window will always be shown at start-up.
For a
D-SETTLEMENT
installation based on a license dongle, the Modules tab will just show the
modules that may be used.
The Vertical Drains module is only available in combination with the 2D Geometry module.
Figure 3.6: Program Options window, Modules tab
Click this button to see which modules are (at this moment) in used and
who (within the company) is using them.
Click this button to borrow the selected modules for a certain period. The
modules will be taken from the server pool and will be available on this
computer even if no connection to the license server is available. Set the
date and time for the expiration of the borrowing and press OK.
Click this button to end the borrow immediately.
3.3 Help menu
The Help menu allows access to different options.
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3.3.1 Error Messages
If errors are found in the input, no calculation can be performed. Those errors must be cor-
rected before performing a new calculation. To display details about those error messages,
select the Error Messages option from the Help menu. They are also written in the *.err file.
They will be overwritten the next time a calculation is started.
Figure 3.7: Error Messages window
3.3.2 Manual
Select the Manual option from the Help menu to view the manual.
3.3.3 Deltares Systems Website
Select Deltares Systems Website option from the Help menu to visit the Deltares Systems
website (www.deltaressystems.com) for the latest news.
3.3.4 Support
Use the Support option from the Help menu to open the Support window in which program
errors can be registered. Refer to section 1.9 for a detailed description of this window.
3.3.5 About D-Settlement
Use the About option from the Help menu to display the About
D-SETTLEMENT
window which
provides software information (for example the version of the software).
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4 Input
Before the analysis can be started, the data for layers, soil properties and loads need to be
inputted.
4.1 Project menu
The Project menu can be used to set the model settings. The project preferences can be set,
the default values of the probabilistic parameters can be entered and it is possible to view the
input file.
4.1.1 Model
On the menu bar, click Project and then choose Model to open the input window. The available
options will depend on the available modules (section 3.2.5). For an overview of different
model limitations see section 1.5.
Figure 4.1: Model window
Dimension the effect of different load types on multiple verticals in a two-
dimensional geometry can be analyzed. With the reduced capabilities
of 1D geometry the effect of uniform loading along one vertical can be
analyzed.
Calculation
model
NEN-Bjerrum (section 16.1) uses the common parameters Cr,Ccand
Cαand represents today’s international de-facto standard. The model
uses a linear strain assumption.
Isotache (section 16.2) is similar to the NEN-Bjerrum model, but uses
the natural strain parameters a, b, c. Natural strain can be advantageous
if large strains are expected. It makes parameters stress-objective and
prevents prediction of unphysical large deformations.
The traditional Dutch NEN-Koppejan model (section 16.3) might be a
logical choice if the model matches available historical parameters and
user experience. Koppejan parameters are traditionally determined on
a linear strain basis. The optional combination with natural strain theo-
retically requires that the parameters were also determined on the same
basis.
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Consolidation
model
section 15.3 describes the influence of excess pore pressures on settle-
ments most accurately. The approximate Terzaghi model (section 15.2)
is applicable in cases where the influence of consolidation is limited, for
instance by application of vertical drains.
Vertical drains Selection of this option enables additional modelling of vertical drains,
with optionally enforced dewatering (section 15.4).
Reliability
Analysis
Selection of this option enables the determination of bandwidth in total
and residual settlement, together with the determination of parameter
sensitivity (section 18.2).
Fit for settle-
ment plate
Selection of this option enables the possibility to perform automatic fits
on measured settlements by parameter scaling (section 5.3). Success-
ful fits require a realistic prediction of the shape of the complete settle-
ment curve. Combination with the Isotache and Darcy models is for this
purpose most suited.
Horizontal
displacements
Selection of this option enables the calculation of horizontal displace-
ments according to De Leeuw tables (De Leeuw,1963).
4.1.2 Probabilistic Defaults
Input of probabilistic defaults is only required if Reliability Analysis has been selected in the
Model window (section 4.1.1). On the menu bar, click Project and then choose Probabilistic
Defaults, in order to modify the default settings for the uncertainty in soil parameters and in
the layer boundary.
Figure 4.2: Probabilistic Defaults window, Consolidation and unit weight tab
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Input
Figure 4.3: Probabilistic Defaults window, Compression tab
Click this button to reset all values to the factory defaults.
Materials
Coefficient of
variation
the mean value determines the default values for the standard deviation
of stochastic soil parameters. Click the Consolidation and unit weight
tab and the Compression tab to see all the available stochastic parame-
ters for the selected material models.
NOTE: The default values of the standard deviation for each material
can be overruled in the Materials window (section 4.2).
Distribution The Lognormal distribution will prevent values below zero. Choosing
None means that
D-SETTLEMENT
will assume that this parameter is de-
terministic instead of stochastic.
Correlation co-
efficient with . . .
The correlation coefficient between the primary compression coefficient
and the other compression parameters. A zero value indicates com-
plete independency. Using a large nonzero value can cause numerical
problems in combination with the probabilistic solution methods.
Layer boundary
Standard devia-
tion
The standard deviation of the boundaries between the different layers, if
a stochastic distribution is used.
Distribution The Lognormal distribution will prevent values below zero. Choosing
None means that
D-SETTLEMENT
will assume that this parameter is de-
terministic instead of stochastic.
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4.1.3 Project Properties
On the menu bar, click Project and then choose Properties to open the input window. The
Project Properties window contains four tabs which allow the settings for the current project
to be changed. Project properties
Project Properties – Identification
Use the Identification tab to specify the project identification data.
Figure 4.4: Project Properties window, Identification tab
Titles Use Title 1 to give the calculation a unique, easily recognisable name.
Title 2 and Title 3 can be added to indicate specific characteristics of
the calculation. The three titles will be included on printed output.
Date The date entered here will be used on printouts and graphic plots for this
project. Either mark the Use current date checkbox on each printout or
enter a specific date.
Drawn by Enter the name of the user performing the calculation or generating the
printout.
Project ID Enter your project identification number.
Annex ID Specify the annex number of the printout.
Mark the checkbox Save as default to use the current settings every time
D-SETTLEMENT
is
started or a new project is created.
Project Properties – View Input
Use the View Input tab to specify the availability of components and the layout settings of the
View Input window (section 2.2.3).
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Input
Figure 4.5: Project Properties window, View Input tab
Display
Info bar Enable this checkbox to display the information bar at the bottom of the
View Input window.
Legend Enable this checkbox to display the legend.
Rulers Enable this checkbox to display the rulers.
Layer colors Enable this checkbox to display the layers in different colors.
Same scale for
x and y axis
Enable this checkbox to display the x and y axis with the same scale in
the top view.
Same scale for
x and z axis
Enable this checkbox to display the x and z (i.e. vertical) axis with the
same scale.
Origin Enable this checkbox to draw a circle at the origin.
Large cursor Enable this checkbox to use the large cursor instead of the small one.
Points Enable this checkbox to display the points.
Loads Enable this checkbox to display the loads.
Verticals Enable this checkbox to display the verticals.
Labels
Points Enable this checkbox to display the point labels.
Loads Enable this checkbox to display the load labels.
Verticals Enable this checkbox to display the vertical labels.
Layers Enable this checkbox to display the layer labels.
Layers
This option can only be used if the checkbox Layers has been marked. Choose how the layers
are indicated: by number, by material number or by material name. This choice determines
the layer coloring as well. If As material numbers or As material names is selected, all layers
with the same material are drawn with the same color.
Grid
Show Grid Enable this checkbox to display the grid points.
Snap to Grid Enable this checkbox to ensure that objects align to the grid automati-
cally when they are moved or positioned in a graph.
Grid Distance Enter the distance between two grid points.
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Selection
Accuracy Mouse selection accuracy, define a large value for a large selection area.
Project Properties – Stresses in Geometry
Use the Stresses in Geometry tab to define the appearance of the Stresses in Geometry
results window (section 6.3).
Figure 4.6: Project Properties window, Stresses in Geometry tab
Display
Info bar Enable this checkbox to display the information bar at the bottom of the
View Input window.
Legend Enable this checkbox to display the legend.
Rulers Enable this checkbox to display the rulers.
Layer colors Enable this checkbox to display the layers in different colors.
Same scale for
x and y axis
Enable this checkbox to display the x and y axis with the same scale.
Origin Enable this checkbox to draw a circle at the origin.
Large cursor Enable this checkbox to use the large cursor instead of the small one.
Points Enable this checkbox to display the points.
Verticals Enable this checkbox to display the verticals.
Labels
Points Enable this checkbox to display the point labels.
Verticals Enable this checkbox to display the vertical labels.
Layers Enable this checkbox to display the layer labels.
Layers
This option can only be used if the checkbox Layers has been marked. Choose how the layers
are indicated: by number, by material number or by material name. This choice determines
the layer coloring as well. If As material numbers or As material names is selected, all layers
with the same material are drawn with the same color.
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Input
Grid
Show grid Enable this checkbox to display the grid points.
Grid distance Enter the distance between two grid points.
Project Properties – Settled Geometry
Use the Settled Geometry tab to set the appearance of the Settled Geometry window (sec-
tion 6.8).
Figure 4.7: Project Properties window, Settled Geometry tab
Display
Infobar Enable this checkbox to display the information bar at the bottom of the
View Input window.
Legend Enable this checkbox to display the legend.
Layer colors Enable this checkbox to display the layers in different colors.
Rulers Enable this checkbox to display the rulers.
Same scale for
x and z axis
Enable this checkbox to display the x and z axis with the same scale.
Origin Enable this checkbox to draw a circle at the origin.
Large cursor Enable this checkbox to use the large cursor instead of the small one.
Points Enable this checkbox to display the points.
Labels
Points Enable this checkbox to display the point labels.
Layers Enable this checkbox to display the layer labels.
Layers
When the option Layers is checked, choose how the layer are indicated: by number, by ma-
terial number or by material name. This choice determines the layer coloring as well. If you
select As material numbers or As material names, all layers with the same material are drawn
with the same color.
Grid
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Show grid Enable this checkbox to display the grid points.
Grid distance Enter the distance between two grid points.
Settled geometry
Enlarged Enable this checkbox to use the enlarge factor.
Enlarge factor Enter a factor to enlarge the drawing of the settled geometry.
4.1.4 View Input File
On the menu bar, click Project and then choose View Input File to open the Input File
window where an overview of the input data is displayed. Click on the Print Active Window
icon to print this file.
4.2 Soil menu
On the menu bar, click Soil and then select Materials to open an input window in which the
soil type properties can be defined. The properties can either be imported directly from an
MGeobase database (Database tab), or be inputted manually (Parameters tab):
Import from database (section 4.2.1);
Manual input of Terzaghi parameters (section 4.2.2);
Manual input of Darcy parameters (section 4.2.3);
Manual input of Isotache parameters (section 4.2.4);
Manual input of NEN-Bjerrum parameters (section 4.2.5);
Manual input of NEN-Koppejan parameters (section 4.2.6);
Additional input for reliability analysis (section 4.2.7);
Additional input for horizontal displacement calculation (section 4.2.8);
4.2.1 Materials – Database
The Database tab in the Materials window is only available if a location of an MGeobase
database was specified in the Locations tab of the Program Options window (section 3.2.3).
Select the Database tab in the Materials window to see the available soil types. Select a
soil type, and use the Import button to import properties the soil type with associated proper-
ties.
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Input
Figure 4.8: Materials window, Database tab
4.2.2 Materials – Parameters Terzaghi
If the Terzaghi consolidation model was selected in the Model window (section 4.1.1), then the
Terzaghi parameters can be specified in the Consolidation and unit weight tab of the Materials
window (Figure 4.9).
The Terzaghi model determines the approximate influence of consolidation, by modification
of the theoretical drained settlements using a so-called coefficient of consolidation cv. See
section 1.5.1 for a comparison with the Darcy model, and see section 15.2 for background
information.
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Figure 4.9: Materials window, Consolidation and unit weight tab for Terzaghi model
Drained Mark this checkbox to specify that the layer acts as a drained
boundary for clusters of consolidation layers.
Total unit weight
above phreatic level
The unit weight of the unsaturated soil above the user-defined
phreatic line.
Total unit weight
below phreatic level
The unit weight of the saturated soil below the user-defined
phreatic line.
Vertical consolidation
coefficient
Terzaghi’s well-known consolidation coefficient for flow in vertical
direction.
Ratio hor./vert.
consolidation coef.
Only for vertical drainage (section 4.1.1): the ratio between the
horizontal and vertical consolidation coefficients.
Note: In the previous versions of the program (version 7.3 and earlier), it was possible to
define three types of soil for Terzaghi model: Creeping,Permeable or Impervious.Creep-
ing corresponds now with a standard input. Permeable is now changed into Drained and
Impervious does not exist anymore. Impervious layers can be modelled using a very small
consolidation coefficent.
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Input
4.2.3 Materials – Parameters Darcy
If the Darcy consolidation model was selected in the Model window (section 4.1.1), the Terza-
ghi parameters can be specified in the Consolidation and unit weight tab of the Materials
window (Figure 4.10).
The improved and accurate Darcy model is the preferred consolidation model since release
8.2. Darcy solves numerically the transient development of excess heads along verticals and
allows for a gradually developing effect of submerging on effective loading. The Darcy model
is able to use the same input parameters as the Terzaghi model.
Figure 4.10: Materials window, Consolidation and unit weight tab for Darcy model
Drained Mark this checkbox to specify that the layer acts as a drained
boundary for clusters of consolidation layers.
Total unit weight
above phreatic level
The unit weight of the unsaturated soil above the user-defined
phreatic line.
Total unit weight below
phreatic level
The unit weight of the saturated soil below the user-defined
phreatic line.
Storage There are three ways to define the vertical permeability kv(see
the Darcy storage Equation 15.6):
-Vertical consolidation coefficient:
D-SETTLEMENT
will deduct a
strain dependent kvat each location from the vertical consolida-
tion coefficient for virgin loading, using Equation 15.8.
-Constant permeability: direct input of kv.
-Strain dependent permeability:kvis a strain dependent perme-
ability according to Equation 15.7.
Vertical consolidation
coefficient Cv
The coefficient of consolidation cvfor flow in vertical direction.
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Permeability strain
modulus
The permeability strain modulus is the ratio Ck/(1 + e0)where
Ckis the permeability strain factor and e0the initial void ratio.
The permeability strain modulus proves to be equal to the NEN-
Bjerrum primary consolidation parameter CR
Vertical permeability The initial value of the vertical permeability at undeformed state.
Ratio horizon-
tal/vertical perme-
ability
The ratio between the horizontal and vertical permeabilities, used
by
D-SETTLEMENT
for vertical drainage modelling (section 4.1.1).
Ratio hor./vert. con-
solidation coef.
The ratio between the horizontal and vertical consolidation co-
efficient, used by
D-SETTLEMENT
for vertical drainage modelling
(section 4.1.1).
4.2.4 Materials – Parameters Isotache
If the Isotache calculation model was selected in the Model window (section 4.1.1), then
the Isotache parameters can be specified in the Compression tab of the Materials window
(Figure 4.11).
D-SETTLEMENT
s a/b/c Isotache model (section 16.2) is based on natural strain, and uses a
rate type formulation. This means that all inelastic compression is assumed to result from
visco-plastic creep. The model is superior in cases with large strains and is able to describe
not only virgin loading but also unloading and reloading. The objective natural parameters
can be derived simply from common oedometer tests (section 17.4), or from compression
parameters for other models (section 17.7).
Figure 4.11: Materials window, Compression tab for Isotache model
Preconsolidation
pressure (σp)
Preconsolidation pressure in the middle of a layer. The preconsoli-
dation pressure is the highest vertical stress experienced in the past.
D-SETTLEMENT
will use a vertical gradient equal to the initial stress
gradient.
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Input
Pre-overburden
pressure (POP)
The Pre-Overburden Pressure (POP) is defined as the preconsolida-
tion pressure minus the initial in-situ vertical effective stress.
Overconsolidation
ratio (OCR)
The Overconsolidation Ratio (OCR) is defined as the ratio of precon-
solidation pressure and in-situ vertical effective stress. The corre-
sponding equivalent age (according to Equation 16.18 page 311) is
shown in grey in the Equivalent age field. This enables to check if
the combination of the OCR value with the compression parameters
a, b, and c is realistic.
Equivalent age The equivalent age is an alternative input option for the overconsoli-
dation ratio. It expresses the required time after virgin loading, if the
overconsolidation would have been caused by ageing only. The cor-
responding OCR (according to Equation 16.18 page 311) is shown
in grey in the Overconsolidation ratio field.
Reloading/swelling
constant (a)
The Isotache reloading/swelling constant arelates natural strain dur-
ing recompression or swell to the change of vertical effective stress.
Primary compres-
sion constant (b)
The Isotache primary compression constant brelates natural strain
during virgin loading to the change of vertical effective stress.
Secondary
compres-
sion constant (c)
The Isotache secondary compression constant relates natural strain
to the change of time. A zero value indicates non-creeping soil.
Note: OCR, POP or Equivalent age, together with the compression parameters a,band c,
determine the initial creep rate. See section 17.2 for background information.
4.2.5 Materials – Parameters NEN-Bjerrum
If the NEN-Bjerrum calculation model was selected in the Model window (section 4.1.1), the
NEN-Bjerrum parameters can be specified in the Compression tab of the Materials window
(Figure 4.12).
The NEN-Bjerrum model (section 16.1) is based on linear strain, and uses the same rate type
formulation as the a/b/c Isotache model. The common NEN-Bjerrum soil parameters Cc,Cr
and Cαcan be derived simply from oedometer tests (section 17.3). Applicability of linear
strain requires that parameters are determined at the appropriate stress level.
The NEN-Bjerrum compression parameters can either be inputted as ratios (Figure 4.12) or
as indices (Figure 4.13).
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Figure 4.12: Materials window, Compression tab for NEN-Bjerrum model (Input as ratio)
Preconsolidation
pressure (σp)
Preconsolidation pressure in the middle of a layer. The stress gra-
dient is equal to the initial stress gradient (section 5.1.2). The pre-
consolidation pressure is the highest vertical stress experienced
in the past.
Pre-overburden
pressure (POP)
The Pre-Overburden Pressure (POP) is defined as the preconsol-
idation pressure minus the initial in-situ vertical effective stress.
Overconsolidation
ratio (OCR)
The Overconsolidation Ratio (OCR) is defined as the ratio of pre-
consolidation pressure and in-situ vertical effective stress. Press-
ing the TAB key will show the corresponding equivalent age, ac-
cording to Equation 16.18 of page 311. This enables you to check
if the combination of the OCR value with the compression param-
eters is realistic.
Equivalent age The equivalent age is an alternative input option for the overcon-
solidation ratio. It expresses the required time after virgin loading,
if the overconsolidation would have been caused by ageing only.
Pressing the TAB key will show the corresponding OCR, accord-
ing to Equation 16.18 of page 311.
Reloading/Swelling
ratio (RR)
The reloading/swelling ratio is used to calculate the primary set-
tlement below preconsolidation stress. The parameter relates the
linear strain to the logarithm of stress during un-reloading.
Compression ratio
(CR)
The compression ratio is used to calculate the primary settlement
above preconsolidation stress. The parameter relates the linear
strain to the logarithm of stress during virgin loading.
Coefficient of
secondary
compression (Ca)
The secondary compression coefficient is used to calculate the
secondary (time dependent) settlement. The parameter relates
the linear strain to the logarithm of time after virgin loading. A
zero value indicates non-creeping soil.
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Input
Figure 4.13: Materials window, Compression tab for NEN-Bjerrum model (Input as index)
Note: OCR, POP or Equivalent age together with the compression parameters determine
the initial creep rate. See section 17.2 for background information.
Reloading/Swelling
index (Cr)
The reloading/swelling index is used to calculate the primary settle-
ment below preconsolidation stress. The parameter relates the void
ratio to the logarithm of stress during un-reloading.
Compression
index (Cc)
The compression index is used to calculate the primary settlement
above preconsolidation stress. The parameter relates the void ratio
to the logarithm of stress during virgin loading.
Coefficient of
secondary
compression (Ca)
The secondary compression coefficient is used to calculate the sec-
ondary (time dependent) settlement. The parameter relates the lin-
ear strain to the logarithm of time after virgin loading. A zero value
indicates non-creeping soil.
Initial void ratio
(e0)
The initial void ratio is used by
D-SETTLEMENT
to convert the com-
pression indices into the compression ratios.
4.2.6 Materials – Parameters NEN-Koppejan
If the NEN-Koppejan calculation model was selected in the Model window (section 4.1.1), the
NEN-Koppejan parameters can be specified in the Compression tab of the Materials window
(Figure 4.14).
NEN-Koppejan’s model (section 16.3) is based on separate primary (instantaneous) and sec-
ondary (creep) contributions to the settlement. The model should be used prudently in case of
load removal, because of its limitations. Another major difference with the NEN-Bjerrum model
is the assumed stress-dependency of secondary settlements. The classic NEN-Koppejan
model is based on linear strain.
D-SETTLEMENT
offers an optional extension to natural strain
(section 16.3.3).
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Figure 4.14: Materials window, Compression tab for NEN-Koppejan model
Preconsolidation
pressure (σp)
Preconsolidation pressure in the middle of a layer. The pre-
consolidation pressure is the highest vertical stress expe-
rienced in the past. By default the stress gradient is equal
to the initial stress gradient, however the NEN-Koppejan
model allows to defined other types of distribution and up-
date of the preconsolidation stress via the Calculation Op-
tions window (section 5.1.2): constant or parallel to the ef-
fective stress and constant or update at each load-step.
Overconsolidation ratio
(OCR)
The ratio between preconsolidation pressure and initial ver-
tical stress
Pre-overburden
pressure (POP)
The Pre-Overburden Pressure (POP) is defined as the pre-
consolidation pressure minus the initial in-situ vertical ef-
fective stress.
Primary compression coeffi-
cient below preconsolidation
pressure (Cp)
The primary compression coefficient is used to calculate
the primary settlement.
Primary compression coeffi-
cient above preconsolidation
pressure (Cp’)
The primary compression coefficient is used to calculate
the primary settlement.
Secular compression coeffi-
cient below preconsolidation
pressure (Cs)
The secular compression coefficient is used to calculate
the secondary (time dependent) settlement.
Secular compression coeffi-
cient above preconsolidation
pressure (Cs’)
The secular compression coefficient is used to calculate
the secondary (time dependent) settlement.
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Input
Ap and As approximation us-
ing Cp end Cs’
Mark this checkbox to approximate the swelling constants
Apand Asto Cpand s’ respectively. This approximation
is reasonable if the unloading step happens when stresses
are above the preconsolidation pressure.
Primary swelling constant
(Ap)
The primary swelling constant for unloading.
Secondary swelling constant
(As)
The secondary swelling constant for unloading. A large
value of Asimplies that there will be no effect of load re-
moval on creep. A large value is therefore only valid for
cases with initial unloading.
4.2.7 Materials – Reliability Analysis
The input of reliability analysis parameters in the Materials window is only available if the
Reliability analysis checkbox in the Model window (section 4.1.1) was marked.
Unmark the Use probabilistic defaults checkbox to overrule the default values for the standard
deviation, the stochastic distribution and the correlation between soil parameters in a certain
layer as defined in the Probabilistic Defaults window (section 4.1.2). See section 18.2 for
background on reliability and sensitivity analysis.
Figure 4.15: Materials window, Compression tab for reliability analysis
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4.2.8 Materials – Horizontal Displacements
The Horizontal displacements tab in the Materials window (Figure 4.16) is only available if the
Horizontal displacements checkbox in the Model window (section 4.1.1) was marked. The
calculation of horizontal displacements is based on De Leeuw theory (De Leeuw,1963). For
background information, see section 18.3.
Figure 4.16: Materials window, Horizontal displacements tab
Layer behaviour The behaviour (Stiff,Elastic or Foundation) of the layer must be spec-
ified. De Leeuw theory assumes an elastic incompressible cluster of
layers based on foundation layer(s) and eventually covered with stiff
layer(s). Therefore, only the system of layers presented in the figure
below is allowed where:
Elastic and foundation layer should be present at least one time;
Stiff layer (if present) should not be positioned below elastic or foun-
dation layer
Other systems will lead to fatal error during calculation.
Elasticity (E) Enter the elastic modulus of the elastic soil layer. Mark the Use de-
fault elasticity option to use the elasticity automatically calculated by
D-SETTLEMENT
according to De Leeuw and Timmermans (based on
the dry unit weight).
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Input
4.3 Geometry menu
On the menu bar, click Geometry to display the menu options. These options are explained
in the following sections.
New (section 4.3.1). Start creating a new geometry manually.
New Wizard (section 4.3.2). Create a new geometry using a wizard.
Import (section 4.3.3). Import a (settled) geometry file in the Deltares exchange format.
Import from database (section 4.3.4). Import a geometry from an MGeobase database.
Export (section 4.3.5). Save a geometry file for exchange with other Deltares Systems
Geo-programs.
Export as Plaxis/Dos (section 4.3.6). Save a geometry file in a different format.
Limits (section 4.3.7). Set the range of the horizontal co-ordinates.
Points (section 4.3.8). Add or manipulate points.
Import PL-line (section 4.3.9). Import piezometric level lines from an existing MPL file.
PL-lines (section 4.3.10). Add or manipulate piezometric level lines.
Phreatic line (section 4.3.11). Define phreatic level lines.
Layers (section 4.3.12). Define or modify layer boundaries and corresponding soil
types.
PL-lines per layer (section 4.3.13). Select the piezometric level line at the bottom and
top of each layer.
Check geometry (section 4.3.14). Check the validity of the geometry.
4.3.1 New
Select this option to display the View Input window (Geometry tab), showing only the geom-
etry limits (with their default values) of the geometry. It is possible to now start modelling the
geometry.
However, it is possible to create a new geometry faster and easier using the Geometry Wizard.
This wizard involves a step-by-step process for creating a geometry.
4.3.2 New Wizard
To use the geometry wizard, open the Geometry menu and choose New Wizard. This option
will guide the user step-by-step through the process of creating a geometry. Using this wiz-
ard significantly reduces time and effort required to enter data. The wizard uses predefined
shapes and soil types. If more flexibility is required, the View Input window (Geometry tab)
can also be used (section 7.3) in a more general way.
New Wizard – Basic Layout
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Figure 4.17: New Wizard window, Basic Layout
In the first screen (Basic Layout) of the New Wizard window, the basic framework of the project
can be entered. The graphic at the top of the window explains the required input. When satisfy
with the input, just click the Next button to display the next input screen.
New Wizard – Shape Selection
Figure 4.18: New Wizard window, Top Layer Shape screen
In the second screen (Top Layer Shape) of the New Wizard window, one of nine default top-
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Input
layer shapes can be selected. A red frame indicates the selected shape. Click the Previous
button to return to the Basic Layout screen, or the Next button to display the next input screen
with shape-specific input data.
New Wizard – Shape Definition
Figure 4.19: New Wizard window, Top Layer Specification screen
In the third screen (Top Layer Specification) of the New Wizard window, the sizes for the
selected top layer shape can be specified.
New Wizard – Material types
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Figure 4.20: New Wizard window, Material types screen
In the fourth screen (Material Types) of the New Wizard window, the materials used for the
layers in the project can be specified. The number of layers was defined in the first screen
(Basic Layout). The materials that can be chosen from are predefined and given in Table 4.1.
Table 4.1: Predefined materials in D-Settlement
Material type Unsaturated weight
[kN/m3]
Saturated weight
[kN/m3]
Muck 11 11
Peat 12 12
Soft Clay 14 14
Medium Clay 17 17
Stiff Clay 19 19
Loose Sand 17 19
Dense Sand 19 21
Sand 18 20
Gravel 18 20
Loam 20 20
The materials for each layer can be selected individually (using the selection boxes at the
left-hand side of the screen) or one material for each layer can be selected at once (using the
selection box at the top right of the screen). The parameters of each material can also be
reviewed.
New Wizard – Summary
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Input
Figure 4.21: New Wizard window, Summary screen
The last screen (Summary) of the New Wizard window displays an overview of the data
entered in the previous wizard screens. If necessary, click Previous to go back to any screen
and change the data as required. Click Finish to confirm the input and display the geometry
in the View Input Geometry window. In this window, the geometry can be edited or completed
graphically as described in section 7.3. Of course, the Geometry menu options can also be
used for this purpose (section 4.3).
If the input contains errors, the Error Report window opens (when clicking the Finish button)
showing the list of encountered errors and giving for each of them a solution. Click Close to
close the Error Report window and use the Previous button of the New Wizard window to
change the data as required.
4.3.3 Import
This option displays a standard file dialog for selecting an existing geometry stored in a ge-
ometry file, or in an existing input file for
D-SETTLEMENT
,
D-GEO STABILITY
(formerly known as
MStab),
D-GEO PIPELINE
(formerly known as MDrill) or MSeep. For a full description of these
programs and how to obtain them, visit www.deltaressystems.com.
When selecting the geometry, it is imported into the current project, replacing the current
geometry. The imported geometry is displayed in the View Input window (Geometry tab). It
is also possible to use this option to analyze the settled geometry at different stages, as all
other input is retained.
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4.3.4 Import from Database
This option displays the Select geometry dialog for importing a geometry from an existing
MGeobase database.
Figure 4.22: Select geometry window
Again, the imported geometry will replace the current one and will be displayed in the View
Input window (Geometry tab).
Note: This option is only available when the correct database directory has been speci-
fied using the Locations tab in the Program Options window (see section 3.2.3). For more
information on MGeobase, visit www.deltaressystems.com.
4.3.5 Export
This option displays a standard Save As dialog that enables to choose a directory and a
filename in which to save the current geometry. The file will be saved in the standard geometry
format for the Deltares tools. Files in this format can be used in a multitude of Deltares geo-
programs, such as
D-GEO STABILITY
(formerly known as MStab),
D-SETTLEMENT
, MSeep and
D-GEO PIPELINE
(formerly known as MDrill). For a full description of these programs and how
to obtain them, visit www.deltaressystems.com.
4.3.6 Export as Plaxis/DOS
This option displays the Save As Plaxis/DOS dialog that enables to choose a directory and a
filename in which to save the current geometry. The file will be saved using the old DOS-style
geometry format for the Deltares Systems Geo-programs. Files in this format can be used
by the finite element program Plaxis and in old DOS-based versions of Deltares Systems
Geo-programs such as
D-GEO STABILITY
(DOS) and MZet (DOS).
Saving files of this type will only succeed, however, if the stringent demands imposed by the
old DOS style are satisfied:
number of layers 20
number of PL-lines 20
number of lines per boundary <50
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Input
total number of points 500
To be able to differentiate between an old DOS-style file and a normal geometry file, the file
dialog that prompts for a new file name for the old DOS-style geometry file provides a default
file name, prefixing the current name with a ‘D’.
4.3.7 Limits
Use this option to edit the geometry limits.
Figure 4.23: Geometry Limits window
A limit is a vertical boundary defining the ‘end’ at either the left or right side of the geometry.
It is defined by an X co-ordinate only.
Note: A limit is the only type of element that cannot be deleted. The values entered here are
ignored if they resulted in an invalid geometry.
4.3.8 Points
Use this option to add or edit points that can be used as part of layer boundaries or PL-lines.
Figure 4.24: Points window
A point is a basic geometry element defined by its co-ordinates. Since the geometry is re-
stricted to two dimensions, it allows defining an X and Y co-ordinate only.
Note: When a point is to be deleted,
D-SETTLEMENT
will check whether the point is used as
part of a PL-line or layer boundary. If so, a message will be displayed.
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Figure 4.25: Confirm window for deleting used points
When Yes is clicked, all layer boundaries and/or PL-lines using the point will also be deleted.
Every change made using this window (Figure 4.24) will only be displayed in the underlying
View Input window (Geometry tab) after closing this window using the OK button. When
this button is clicked, a validity check is performed on the geometry. Any errors encountered
during this check are displayed in a separate window. These errors must be corrected before
you can close this window using the OK button. Of course, it is always possible to close the
window using the Cancel button, but this will discard all changes.
4.3.9 Import PL-line
Use this option to display the Import PL-line dialog for importing a Piezometric Level (PL) line
from an existing MPL file. Such file is made using the WATEX program of Deltares: in tab
Head-Location Plot, click on the button “Export... and fill in a file name in the “Export Water
Pressure Line” window.
4.3.10 PL-lines
Use this option to add or edit Piezometric Level lines (PL-lines) to be used in the geometry.
A PL-line represents the pore pressures in the soil. A project can contain several PL-lines as
different soil layers can have different piezometric levels. In section 4.3.13 it is described how
different PL-lines are assigned to different layers.
Figure 4.26: PL-Lines window
In the lower left part of the window, it is possible to use the buttons to Add,Insert and Delete
PL-lines. The selection box can be used to navigate between PL-lines that have already been
defined.Use the table to add/edit the points identifying the PL-lines. It is only possible to select
points that are not attached to layer boundaries (section 4.3.12).
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Input
Note: It is only possible to manipulate the Point number column – that is, the co-ordinate
columns are purely for informative purposes. To manipulate the co-ordinates of the points,
select the Points option from the Geometry menu (see section 4.3.8).
Every change made using this window will only be displayed in the underlying View Input
window (Geometry tab) after closing this window using the OK button. When clicking this
button, a validity check is performed on the geometry. Any errors encountered during this
check are displayed in a separate window. These errors must be corrected before this window
can be closed using the OK button. Of course, it is always possible to close the window using
the Cancel button, but this will discard all changes.
4.3.11 Phreatic Line
Use this option to select the PL-line that acts as a phreatic line. The phreatic line (or ground-
water level) is used to mark the border between dry and wet soil.
Figure 4.27: Phreatic Line window
Select the appropriate line number from the drop-down list and click the OK button. At least
one PL-line must be defined to be able to pick a Phreatic Line here.
4.3.12 Layers
This option enables to add or edit layers to be used in the geometry. A layer is defined by
its boundaries and its material. Use the Boundaries (seen here in Figure 4.28) to define the
boundaries for all layers by choosing the points that identify each boundary.
Figure 4.28: Layers window, Boundaries tab
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On the left-hand side of the window, it is possible to add, insert, delete or select a boundary.
In the table on the right, it is possible to modify or add the points that identify the selected
boundary.
Note: It is only possible to select points that are not attached to PL-lines (section 4.3.10).
Note: It is only possible to manipulate the Point number column, because the co-ordinate
columns are purely for informative purposes. To manipulate the co-ordinates of the points,
select the Points option in the Geometry menu (see section 4.3.8).
Note: When inserting or adding a boundary, all points of the previous boundary (if this exists)
are automatically copied. By default, the material of a new layer is set equal to the material of
the existing layer just beneath it.
The Materials to layers tab enables to assign materials to the layers.
Figure 4.29: Layers window, Materials tab
On the left of the screen, a list containing all defined materials (see the Materials option in
the Soil menu (section 4.2]) is displayed. On the right, a list of all defined layers together with
their assigned materials (if available) is displayed.The layers are listed from top to bottom as
displayed in the View Input window (Geometry tab).
To assign a material to a layer, first select that layer on the right of the window. Then select
the required material on the left of the window. Finally, click the Assign button.
Every change made using this window will only be displayed in the underlying View Input
window (Geometry tab) after this window is closed using the OK button. When clicking this
button, a validity check is performed on the geometry. If errors are encountered, a dialog
window asks if auto-correction should be tried. Remaining errors are reported and can be
corrected manually. The error correction is confirmed by clicking the OK button and discarded
by clicking the Cancel button.
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Input
4.3.13 PL-lines per Layer
Use this option to define the top and bottom PL-lines for the defined layers. The PL-lines
represent the hydrostatic heads at the boundaries of soil layers. For each soil layer, two PL-
line number can be entered – one that corresponds to the top of the soil layer, and one that
corresponds to the bottom. Therefore, different PL-lines can be defined for the top and the
bottom of each soil layer. To do this, select the appropriate PL-line at top / PL-line at bottom
field and enter the appropriate number.
D-SETTLEMENT
has reserved two numbers for special
cases: 0 and 99.
Figure 4.30: PL-lines per Layer window
The PL-lines represent the pore pressure in a soil layer. For every soil layer (except the bottom
layer), two PL-line numbers can be entered – one that corresponds to the top of the soil layer,
and one that corresponds to the bottom. For the bottom soil layer, no second PL-line number
is required. For this layer a hydrostatic increase of the pore pressure is automatically assumed
from the pore pressure at the top of the layer downwards.
The following values can be used as PL-line numbers (N):
0<N<99 The number corresponds to one of the PL-lines defined during the geom-
etry input. Capillary water pressures are not used – that is, if a negative
water pressure is calculated for a point above the phreatic line, the water
pressure in that point is defined as 0.
N = 0 Each point within the layer has a water pressure equal to 0 (Define 0 for
PL-line at top of layer).
N = 99 It is possible to have a number of overlying soil layers with a non-hydrostatic
pore pressure (for example, a number of layers consisting of cohesive soil).
In this case, a large number of PL-lines would have to be calculated, one or
two for each layer. To avoid this, Deltares Geo-software is able to interpolate
across layer boundaries. For layers with a non-hydrostatic pore pressure,
99 can be entered as the PL-line number. For this layer, the interpolation
will take place between the PL-line belonging to the first soil layer above
with a real PL-line number, and the PL-line belonging to the first soil layer
below with a real PL-line number. The first and the last soil layer must
therefore always have a real PL number.
NOTE: A real PL-line number is not equal to 99.
Water pressures above the phreatic line are set to zero.
When clicking the OK button, a validity check is performed on the geometry. Any errors
encountered during this check are reported. A dialog window enables to disregard or correct
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the errors. The error correction is confirmed by clicking the OK button and discarded by
clicking the Cancel button.
4.3.14 Check Geometry
Select this option to verify the validity of the geometry. All requirements are checked. If the
geometry complies with all the requirements, a message will confirm this.
Figure 4.31: Information window on confirmation of a valid geometry
If any errors are encountered during this check, they are displayed in a separate window.
4.4 GeoObjects menu
On the menu bar, click GeoObjects to display a menu containing:
Verticals (section 4.4.1)
Vertical drains (section 4.4.2)
4.4.1 Verticals
In the Verticals input window, the (horizontal) X co-ordinate for each vertical must be defined
or generated.
D-SETTLEMENT
will calculate settlements along each of these verticals. At least
one vertical is necessary to make a calculation. The position of the (out-of-plane) Z co-
ordinate is only relevant for circular or rectangular loads. It is possible to get
D-SETTLEMENT
to automatically generate verticals in all nodes of the geometry and non-uniform loads. At
these points, verticals are required to view the settled geometry after calculation or to write
the settled geometry to a file. In addition, it is possible to generate a range of verticals with an
interval.
Figure 4.32: Verticals window
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Input
X co-ordinate Defines the places in geometry in x direction where the settlement
will be calculated.
Z co-ordinate Defines the place in geometry in z direction where the settlement will
be calculated. This is only relevant for circular or rectangular loads.
The z co-ordinate is equal for all verticals.
Discretisation (Only available for Darcy consolidation model, see section 4.1.1).
The total number of elements per layer (section 15.3.4).
Automatic gen-
eration of X co-
ordinates
Use the toggle buttons to specify whether
D-SETTLEMENT
must gen-
erate verticals in every geometry node or with an interval.
First The start of the range for which verticals must be generated.
Last The end of the range for which verticals must be generated.
Interval The distance between two generated verticals.
Click on the Generate button to execute the automatic generation of
verticals.
4.4.2 Vertical Drains
The Vertical Drains window is only available if the corresponding option has been marked in
the Model window (section 4.1.1).
At the top left of the input window, select a strip, column or sand wall drain type (Figure 4.33).
Figure 4.33: Vertical Drains window (Drain Type sub-window)
D-SETTLEMENT
extends the one-dimensional solution of the pore pressure distribution with a
so-called leakage term. Enforced consolidation by dewatering (BeauDrain, IFCO method,
PTD) or vacuum consolidation can also be modeled. For background, see section 15.4.
Vertical Drains – Line shaped drains (Strip and Column)
Figure 4.34: Vertical Drains window, Strip and Column drains (Positioning input)
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Horizontal Range Enter the left (From) and right (To) limits of the drained area. This
area is represented by a blue arrow in the View Input window (Input
tab) (section 2.2.3).
Bottom position The (vertical) Y co-ordinate of the bottom end of the vertical drain.
The Bottom Position is represented by a blue arrow in the View Input
window (Input tab) (section 2.2.3).
Center to center
distance
The actual spacing between the drains.
Diameter The diameter of the Column drain.
Width The actual width of the Strip drain.
Thickness The actual thickness of the Strip drain.
Grid In the drop down menu, select the geometry of grid: Undetermined,
Rectangular or Triangular.
Figure 4.35: Vertical Drains window, Strip and Column drains (Drainage Schedule input)
Drainage Schedule with strips or columns: Off
Start of drainage The time t at which the drain becomes active.
D-SETTLEMENT
as-
sumes that the water head in the drain equals the phreatic level (sec-
tion 4.3.11).
Phreatic level in
drain
The water head in the drain during drainage.
Drainage Schedule with strips or columns: Simple Input
Start of drainage The time at which the drain becomes active.
Begin time The time at which dewatering (i.e. a certain water level and air pres-
sure) starts.
End time The time at which dewatering stops. Before and after enforced de-
watering,
D-SETTLEMENT
assumes that the water head in the drain
equals the phreatic level (section 4.3.11).
Underpressure The enforced underpressure pair during dewatering. Usual values for
enforced dewatering methods vary between 35 and 50 kPa (CUR).
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Input
Water head during
dewatering
The vertical level where the negative pore pressure equals the en-
forced underpressure during dewatering. In case of enforced dewa-
tering on top, this level is equal to the top level of the drain. In case
of vacuum consolidation, the level is equal to the impermeable cover
of the drainage layer, measured at the location where the underpres-
sure is applied.
NOTE: The input value is the position where the water pressure
equals the applied underpressure, and therefore not the position
where the water level equals the atmospheric pressure.
Start of drainage The time t at which the drain becomes active.
D-SETTLEMENT
as-
sumes that the water head in the drain equals the phreatic level (sec-
tion 4.3.11).
Phreatic level in
drain
The water head in the drain during drainage.
Drainage Schedule with strips or columns: Detailed Input
Time The time at which dewatering (i.e. a certain water level and air pres-
sure) is active.
Underpressure This value is zero for vertical drains without enforced underpressure.
In case of enforced dewatering or vacuum consolidation on top, it rep-
resents the enforced underpressure pair at time t. Usual values for
enforced dewatering methods vary between 35 and 50 kPa (CUR).
Water head The vertical level where the negative pore pressure equals the en-
forced underpressure during dewatering. In case of enforced dewa-
tering on top, the level is equal to the top level of the drain. In case
of vacuum consolidation, the level is equal to the impermeable cover
of the drainage layer, measured at the location where the underpres-
sure is applied.
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Vertical Drains – Sand wall
Figure 4.36: Vertical Drains window, Sand wall (Positioning input)
Horizontal Range Enter the left (From) and right (To) limits of the drained area. This
area is represented by a blue arrow in the View Input window (Input
tab) (section 2.2.3).
Bottom position The vertical co-ordinate of the bottom end of the granular wall.
Center to center
distance
The centre to centre distance between the granular walls.
Width The width of the granular wall.
Position of the
drain pipe
Only for enforced dewatering: The vertical co-ordinate of the
drainage tube at the bottom of the vertical drain zpipe.
Figure 4.37: Vertical Drains window, Sand wall (Drainage Schedule input)
Drainage Schedule with sand walls: Off
Start of drainage The time t at which the drain becomes active.
Phreatic level in
drain
The water head in the drain during drainage.
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Input
Drainage Schedule with sand walls: Simple Input
Start of drainage The time at which the drain becomes active.
Phreatic level in
drain
The water head in the drain during drainage.
Begin time The time at which dewatering (i.e. a certain tube pressure and air
pressure) starts.
End time The time at which dewatering stops. Before and after enforced de-
watering,
D-SETTLEMENT
assumes that the water head in the drain
equals the phreatic level (section 4.3.11).
Underpressure The enforced underpressure pair during dewatering. This value can
vary between 0 and 30 kPa, if an impermeable cover is applied on
top (CUR).
Tube pressure
during dewatering
The water pressure ppipe in the drainage tube during dewatering. A
common input value during enforced dewatering is 10 kPa (CUR).
Drainage Schedule with sand walls: Detailed Input
Time The time at which dewatering (i.e. a certain water level and air pres-
sure) is active.
Underpressure The enforced underpressure pair at time t. This value can vary be-
tween 0 and 30 kPa, if an impermeable cover is applied on top (CUR).
Tube pressure The water pressure ppipe in the drainage tube at time t. A common
input value during enforced dewatering is 10 kPa (CUR). Without en-
forced dewatering, you must determine this pressure from the as-
sumed position of the free phreatic level in the granular wall.
4.5 Water menu
On the menu bar, click Water and choose Properties to open the Water Properties window
(section 4.5.1).
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4.5.1 Water Properties
In this window, the unit weight of water can be specified.
Figure 4.38: Water Properties window
Unit weight Unit weight of water. The default is 9.81 kN/m3.
4.6 Loads menu
On the menu bar, click Loads to display the following menu options:
Non-Uniform Loads (section 4.6.1), to input non-uniform loads;
Water Loads (section 4.6.2), to input hydraulic pore pressure changes excluding the
excess component;
Other Loads (section 4.6.3), to input loads with:
trapeziform cross-section
circular base
rectangular base
uniform cross-section
tank
4.6.1 Non-Uniform Loads
Choose the Non-Uniform Loads option in the Loads menu to open an input window in which
non-uniform loads can be defined. Use the panel on the left to add loads and enter the
required parameters for each load.
D-SETTLEMENT
assumes that a non-uniform load is caused
by soil self weight. Therefore, the top surface of that load must be defined. The sequence of
loading also must be defined.
D-SETTLEMENT
assumes that the base of a non-uniform load
is equal to the top surface of the previous non-uniform load, in case of load increase. See
section 13.1 for background information, and see section 5.1 for related important options,
such as maintain profile, load submerging and stress distribution in loads.
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Input
Figure 4.39: Non-Uniform Loads window
Initial load Enable this box if the load affects only the initial stresses and if the
load does not cause any creep or consolidation.
D-SETTLEMENT
sets
the time of application at -1.
Time The number of days before the load will be applied. The time must
correspond to the sequence of loading. For initial loads, the time is
set to -1.
Sequence of load-
ing
The sequence of loading must match the time at which the loads will
be applied. To change the sequence of loading, change the order of
the loads in the list by moving them up or down.
End time The time at which a temporary load is removed.
Total unit weight
above the phreatic
level
The unit weight of the unsaturated soil above the phreatic line. Use
negative values in case of unloading.
Total unit weight
below the phreatic
level
The unit weight of the saturated soil below the phreatic line. Use
negative values in case of unloading.
X co-ordinate X co-ordinate (horizontal) of points that define the surface of the load.
The X co-ordinates must be ascending. The first and last co-ordinate
must be located on the surface of the last defined load.
Y co-ordinate Y co-ordinate (vertical) of points that define the surface of the load.
The first and last co-ordinate must be located on the surface of the
last defined load.
The Input from Database button allows connecting material properties from a soil type to a
load. This button can only be clicked if a location of an MGeobase database was specified
in the Program Options window (section 3.2.3).
D-SETTLEMENT
will derive the saturated and
unsaturated unit weight from the selected soil type.
D-SETTLEMENT
will also derive the strength
properties from the database, when writing a
D-GEO STABILITY
input file for a stability analysis
(section 6.10).
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Figure 4.40: Import Gamma Wet/Dry from Database window
After selecting a material from the database,
D-SETTLEMENT
changes the name of the selected
uniform load into the material name. If a uniform load with this name already exists, the
name is extended with a number between parentheses (see example of Figure 4.39 where
the material Sand, clean, stiff was selected twice).The uniform load can be renamed after
importing it from the database. However, if done,
D-GEO STABILITY
will not recognize the
material from an input file that was generated by
D-SETTLEMENT
.
Click the Generate button to generate stepwise loading from input of the final surface position
and the position of the top at the end of each load step. The final surface position is inputted
in the Envelope Points tab and the vertical levels of the top of each intermediate load steps
are inputted in the Top of loads steps tab (see Figure 4.41).
Figure 4.41: Generate Non-Uniform Loads window
X co-ordinate X co-ordinate (horizontal) of points that define the final load surface.
The X co-ordinates must be ascending. The first and last co-ordinate
must be located either on the initial ground surface, or on the surface
of the last defined load.
Y co-ordinate Y co-ordinate (vertical) of points that define the surface of the load.
The first and last co-ordinate must be located on either on the initial
ground surface, or on the surface of the last defined load.
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Input
Top of load steps The vertical levels of the top of the added soil, during subsequent
load steps.
4.6.2 Water Loads
Choose the Water Loads option in the Loads menu to open an input window in which changes
in pore pressure during time can be defined. Use the panel on the left to add water loads,
and select the active PL-lines at top and bottom of each layer. For background information on
the PL-lines, see section 15.1.1.
D-SETTLEMENT
assumes that the initial PL-lines are defined
during geometry creation (section 4.3.10,section 4.3.11,section 4.3.13).
Figure 4.42: Water Loads window
Time The number of days before the load will be applied. During one time
interval, only one water load can be specified.
Phreatic line In this field, select which PL-line will function as the phreatic line.
The phreatic line (or groundwater level) marks the border between
dry and wet soil.
NOTE: This new phreatic line will apply only on the materials, not on
the Non-Uniform Loads.
Layer
D-SETTLEMENT
automatically enters the names of the layers.
PL-line at top The PL-line that corresponds with the top of the layer (see sec-
tion 4.3.10). Use number 99 to get
D-SETTLEMENT
to perform an inter-
polation between adjacent layers, and use number 0 for unsaturated
soil.
PL-line at bottom The PL-line that corresponds with the bottom of the layer.
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4.6.3 Other Loads
Choose the Other Loads option in the Loads menu to open an input window in which prede-
fined shapes of soil loads can be selected. Use the panel on the left to add loads, and enter
the required parameters for each load. The following shapes are available:
trapeziform cross-section;
circular base;
rectangular base;
uniform cross-section;
tank.
Trapeziform Loads
D-SETTLEMENT
assumes that trapeziform loads are caused by soil self weight. See sec-
tion 13.2 for background information.
Figure 4.43: Other Loads window with Trapeziform load
Initial load Enable this box if the load affects only the initial stresses and if the
load should not cause any creep or consolidation.
D-SETTLEMENT
sets the time of application at -1.
Time The number of days before the load will be applied. For initial loads,
the time is set to -1.
Unit weight The weight of the load per m3. For unloading, a negative value can
be entered. Zero is not allowed.
Height Height of the load. For an inverted trapezium, enter a negative
height.
xlLength of the left part of the load.
xmLength of the middle part of the load.
xrLength of the right part of the load. The total length of the (three)
parts must be greater than zero.
XpX co-ordinate of the starting point (left side) of the load.
YpY co-ordinate of the starting point (left side) of the load.
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Input
Circular Loads
Loads with circular base may act on or in the geometry. See section 13.3 for background
information.
Figure 4.44: Other Loads window with Circular load
Initial load Enable this box if the load affects only the initial stresses and if the
load should not cause any creep or consolidation.
D-SETTLEMENT
sets the time of application at -1.
Time The number of days before the load will be applied. For initial loads,
the time is set to -1.
Magnitude The magnitude of the load. For unloading, a negative value can be
entered. Zero is not allowed.
Contact shape fac-
tor
The shape factor αis used to specify the shape of the contact pres-
sure. If α= 1, the contact pressure is constant (represents flexible
footing). If α= 0, a parabolic distribution is used with 0 kN/m2in the
centre, and twice the magnitude at the edge (represents rigid foot-
ing). For more information, refer to Equation 13.1.
Xcp X co-ordinate of the middle point of the circle.
Ycp Y co-ordinate of the middle point of the circle.
Zcp Z co-ordinate of the middle point of the circle.
Radius The radius of the circle.
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Rectangular Loads
loads with rectangular base may act on or in the geometry. See section 13.4 for background
information.
Figure 4.45: Other Loads window with Rectangular load
Initial load Enable this box if the load affects only the initial stresses and if the
load should not cause any creep or consolidation.
D-SETTLEMENT
sets the time of application at -1.
Time The number of days before the load will be applied. For initial loads,
time is set to -1.
Magnitude The magnitude of the load. For unloading, a negative value can be
entered. Zero is not allowed.
Contact shape fac-
tor
The shape factor αis used to specify the shape of the contact pres-
sure. If α= 1, the contact pressure is constant (represents flexible
footing). If α= 0, a parabolic distribution is used with 0 kN/m2in the
centre, and three times the magnitude at the edge (represents rigid
footing).
Xcp X co-ordinate of the middle point of the rectangle.
Ycp Y co-ordinate of the middle point of the rectangle.
Zcp Z co-ordinate of the middle point of the rectangle.
xwidth The dimension of the rectangle in x direction. It must be greater than
zero.
zwidth The dimension of the rectangle in z direction. It must be greater than
zero.
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Input
Uniform Loads
D-SETTLEMENT
assumes that uniform loads are caused by soil self weight. See section 13.5
for background information. The input can be done manually or by automatic generation from
measured surface positions.
Figure 4.46: Other Loads window with Uniform load
Initial load Enable this box if the load affects only the initial stresses and if the
load should not cause any creep or consolidation.
D-SETTLEMENT
sets the time of application at -1.
Time The number of days before the load will be applied. For initial loads,
the time is set to -1.
Unit weight The weight of the load per m3. For unloading, a negative value can
be entered. Zero is not allowed.
Height (H) Height of the load, relative to Yapplication.
Yapplication Y co-ordinate of the level of application.
4.6.3.1 Tank Loads
Storage tank with circular base can be inputted in
D-SETTLEMENT
.
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Figure 4.47: Other Loads window with Tank load
Initial load Enable this box if the load affects only the initial stresses and if the
load should not cause any creep or consolidation.
D-SETTLEMENT
sets the time of application at -1.
Time The number of days before the load will be applied. For initial loads,
the time is set to -1.
Wall load The magnitude of the load induced by the weight of the material in
which the tank is made.
Contact shape fac-
tor
The shape factor αis used to specify the shape of the contact pres-
sure. If α= 1, the contact pressure is constant (represents flexible
footing). If α= 0, a parabolic distribution is used with 0 kN/m2in the
centre, and twice the magnitude at the edge (represents rigid foot-
ing).
Xcp X co-ordinate of the middle point of the circle.
Ycp Y co-ordinate of the middle point of the circle.
Zcp Z co-ordinate of the middle point of the circle.
Internal Radius The internal radius of the tank.
Wall Thickness The wall thickness of the tank.
Internal load The magnitude of the load induced by the weight of the material
stored in the tank.
Click the Generate button uniform to generate uniform loads from imported (SLM or GEF file)
or manually specified surface positions. See Figure 4.48.
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Input
Figure 4.48: Generate Uniform Loads window
Start Yapplication Vertical co-ordinate of the level of application of the first load.
Browse Select a file with measured surface positions (GEF or SLM) to gen-
erate the loading table automatically.
Time The number of days before the load will be applied.
Top New surface position.
Unit weight The weight of the load per m3.
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5 Calculations
On the menu bar, click Calculation to display the following menu options:
Options (section 5.1), to define various general options.
Times (section 5.2) to define time points for tabular output of remaining settlements.
Fit for Settlement Plate (section 5.3), to perform a fit on measured settlements.
Start (section 5.4), to start a regular or a reliability analysis.
Batch Calculation (section 10.5), successive calculations for different input files.
5.1 Calculation Options
In this window, a wide range of specific calculation options can be modified depending on the
geometry dimension and the calculation model:
Input fields for 1D geometry (section 5.1.1).
Input fields for 2D geometry (section 5.1.2).
5.1.1 Calculation Options – 1D geometry
If a 1D dimension option was selected in the Model window (section 5.1.2), the Calculation
Options window contained only few input fields which depend on the calculation model.
Figure 5.1: Calculation Options window for 1D geometry
Dispersion condi-
tions layer bound-
aries
(This parameter is required only for Terzaghi consolidation model).
Use this option to influence the drainage length of the soil layers.
Drainage can be introduced by selecting a drained bottom or top
layer boundary. The selected drainage method will be summarised in
the tabular report. For background information on Terzaghi drainage
conditions, see section 15.2.3.
Stress distribution
Soil
Distribution of the stresses in the underground can be calculated ac-
cording to Buisman or Boussinesq. Boussinesq can be applied only
for the trapeziform and non-uniform loads. For other kind of loads,
Buisman will be used. For background information, see section 14.1.
End of settlement
calculation
Enter the number of days after which the transient settlement is ex-
pected to have ended.
NOTE: Consolidation is only included in the time-settlement curves
and not in the individually reported final settlements.
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Creep rate
reference time
The value of the reference time τ0for the creep part. In practice, this
value can be interpreted as the ratio between 1 day and the unit of
time in the calculation. This means that a large value should be used
when simulating short term settlements, with time steps smaller than
1 day, like in oedometer tests.
NOTE: A value other than 1 day requires consistent input of all other
time-dependent values (section 17.1.2).
Preconsolidation
pressure within a
layer
This parameter is required only for the NEN-Koppejan model.
Choose between a Constant and a Variable preconsolidation pres-
sure in the layers.
When variable (default), the input value is applied to the middle of
the layer. Within the layer, the gradient of the preconsolidation pres-
sure is equal to the gradient of the initial vertical effective stress. In
this case, the Pre Overburden Pressure equals the difference be-
tween the preconsolidation pressure and the vertical effective stress
at middle of the layer (section 17.2).
There are two additional options a