Contents Problem 1 030

Problem 1-030 Problem 1-030

User Manual: Problem 1-030

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Software Verification
PROGRAM NAME:
SAP2000
REVISION NO.:
10
EXAMPLE 1-030
FRAME – MOVING LOADS
IMPORTANT NOTE
This example applies to CSiBridge only. Starting with Sap2000 version 15.00
the example does not apply to Sap2000 because it uses features that are not
supported in Sap2000.
EXAMPLE DESCRIPTION
This example uses a 40-foot-long simple span bridge (beam) to test moving load
load cases. Moving load cases use defined vehicle loads and defined lanes (rather
than the load cases that are used by other analysis types) to calculate the most
severe response resulting from vehicle live loads moving along lanes on the
structure.
A single 12-foot-wide lane with a maximum discretization length of 2 feet is
defined along the center line of the bridge structure. An H20-44 truck load
vehicle and an H20-44L lane load vehicle are created and a vehicle class
containing both the H20-44 and H20-44L vehicles is defined. The moving load
analysis considers both vehicles separately and reports the worst-case response.
In addition to the moving load case, this example also includes a multi-step static
analysis for the H20-44 vehicle. This analysis simulates the truck moving across
the bridge.
For each of the load cases the maximum moment and maximum reaction are
compared with independent results that are either presented in Appendix A of
AASHTO 1990 or hand calculated.
Output stations along the frame element modeling the bridge are specified to be
at a maximum spacing of 2 feet.
TECHNICAL FEATURES OF SAP2000 TESTED
Moving load case
Multi-step static load case for vehicles
EXAMPLE 1-030 - 1
Software Verification
PROGRAM NAME:
SAP2000
REVISION NO.:
10
GEOMETRY, PROPERTIES AND LOADING
Z
X
40'
Material Properties
E = 518,400 k/ft2
ν=0.2
Section Properties
b = 12 ft
d = 1.5 ft
C
CSection C-C
1.5'
12'
Analysis Cases
MOVEINF:Moving load analysis case; each vehicle
is run forward (from joint 1 to 2) and
backward along the lane
MOVEMS:Multi-step static analysis case; H20-44
vehicle is run forward along the lane
1 2
Bridge structure
and lane Lane
14'
8k 32k
H20-44
Truck Load
∞
18k for
moment
only
H20-44 Lane Load
26k for all
response
except
moment
0.640 k/ft
RESULTS COMPARISON
The independent results for all items, except the maximum reaction for the
MOVEMS load case, are taken from tables in Appendix A of AASHTO 1990.
The independent results for the MOVEMS load case are hand calculated.
Load Case Output
Parameter SAP2000 Independent Percent
Difference
MOVEINF
Moving load
case
Max Moment
k-ft 345.6 346.0 -0.1%
Max Reaction
kips 38.789 38.8 0%
MOVEMS
Multi-step static
load case
Max Moment
k-ft 345.5 346.0 -0.1%
Max Reaction
kips 37.192 37.2 0%
The maximum moment in the MOVEINF load case is controlled by the
H20-44 truck load. It is the same as the maximum moment in the MOVEMS load
case, which considers only the truck load.
EXAMPLE 1-030 - 2
Software Verification
PROGRAM NAME:
SAP2000
REVISION NO.:
10
The maximum reaction in the MOVEINF load case is controlled by the
H20-44L lane load. It is larger than the maximum reaction in the MOVEMS load
case, which considers only the truck load.
COMPUTER FILES: Example 1-030
CONCLUSION
The SAP2000 results show an acceptable match with the independent results.
EXAMPLE 1-030 - 3
Software Verification
PROGRAM NAME:
SAP2000
REVISION NO.:
10
HAND CALCULATION
EXAMPLE 1-030 - 4

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