{{Tutorial
name = Variable girder spacing for bridge object |
description = Step by step procedure for developing model with variable girder spacing |
keyword = bridge; bridge modeler |
program = SAP2000 |
version = V14.1.0 |
status = in progress |
type = tutorial |
id = ondrej/test problems/bridge - parametric definition of bridge girder spacing}} |
As of V14.1.0 of the program, it is possible to assign parametric variation to girder spacing and to offsets from reference point to the insertion points.
Key modeling steps
The key modeling steps involve:
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While this tutorial was developed for the SAP2000 bridge modeler, the concept also applies to CSiBridge. |
On this page:
| Table of Contents |
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Key modeling steps
Create a parametric variation through the Bridge > Parametric Variations option.
Assign the parametric variation through the Bridge > Bridge Objects > Modify/Show Bridge Object > Spans > Modify/Show > Modify/Show Section Variation Along Selected Span
"option.
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Example
Consider a 2two-span bridge with two 15m long spans. The deck superstructure consists of 4 four steel girders supporting a cast-in-place slab. The total Total superstructure width is 12m, the girder spacing of the girders is 3m, and the overhangs overhang on each side are is 1.5m long.
The width of .
These specifications may be defined as shown in Figure 1:
Figure 1 - Bridge deck section definition
For the second span, the width linearly increases from 12m to 15m. Let's consider the following two cases: uniform Uniform flare and " one-sided " flare will be considered.
Uniform
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flare
The girder Girder spacing increases from 3m to 4m, while the . The structure is symmetric about the layout line. This can may be modeled as follows:
- Assign
For all girders in the second span, assign linear parametric variation (from 0m to 1m) to girder spacing
for all girders in.
For the second span
.Assign, assign linear parametric variation (from 0m to 3m) to the total deck width
for second span.
"One-Sided" Flare
The girder
Figure 2 - Variable girder spacing for uniform flare
One-sided flare
Girder spacing increases from 3m to 4m, while for both spans, but the right edge of the bridge for both spans is a straight line. This can may be modeled by assigning the following parametric variation , in addition to the parametric variations assigned for uniform flare, the following:
- Assign linear
Linear parametric variation (from 0m to 1.5m) to X offset from the reference point to the insertion point.
See Also
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Figure 3 - Variable girder spacing for one-sided flare
Attachments
SAP2000 V14.1.0 models (zipped .SDB files)
Metadata
Name: Variable girder spacing
Description: Procedure for developing a model with variable girder spacing.
Program: SAP2000
Program Version: 14.1.0
Model ID: na