Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

{{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:

...

Info

While this tutorial was developed for the SAP2000 bridge modeler, the concept also applies to CSiBridge.

On this page:

Table of Contents

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.

...

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.

Image Removed

The width of .

These specifications may be defined as shown in Figure 1:

Image Added

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

...

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

    .

Image Modified

"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.

Image Modified

See Also

...

Figure 3 - Variable girder spacing for one-sided flare

Attachments

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