{{Tutorial

This tutorial describes how to model a composite bridge, with This tutorial describes the modeling process for a composite bridge composed of a concrete slab over steel girders for which the girder height varies between the with variable height between pier sections and midspan sections.

On this page:

Modeling Steps

...

Modeling steps

To obtain the girder-height variation desired, users should assign non-prismatic girders to the bridge deck section to obtain the desired variation.

Create

...

new model from

...

template

• Use "

  Select File > New Model

  ", select "

  > KN, m, C

  "

  units

  and

  > Quick BrIM template.

• Set span lengths to

  "

  '30; 30

  "

  ', and select Steel Girder as the bridge deck-section type

  "Steel Girder"

Define Nonprismatic Steel Girder Sections

• "

  .

Define non-prismatic steel girder sections

• Select Define > Section Properties > Frame Sections

  "

  
  
  

  Use "
  • rename

    Rename the default girder section

    "

    FSEC1

    "

    to

    "

    'GRD 1.22m

    "create copy of "

    '.
    
    

  • Copy the 'GRD 1.22m

    "

    ' section, change the overall height to 2.22m, and save the section as

    "

    'GRD 2.22m

    "

    '.
    
    

  • Select Add New Property > Frame Section Property (other) > Nonprismatic Section to create nonprismatic sections

    "

    'GRD span1

    "

    ' and

    "GRD span2" (via "Add New Property" button, frame section property Other and nonprismatic section) to specify 1.22m deep girder

    'GRD span2'.
    
    

  • Use the previously defined sections 'GRD 1.22m' and 'GRD 2.22m' to specify a 1.22m girder depth for the first 15m of

    the

    length, and a variation from 1.22m

    deep girder

    to 2.22

    deep girder

    for the remaining 15m of the girder length

    using the previously defined sections "GRD 1.22m" and "GRD 2.22m". For "GRD span1" section, the depth will increase, while for "GRD span2 section, the depth will decrease:

Image Removed

Create Bridge Deck Sections

• • . Depth increases for the 'GRD span1' section, and decrease for the 'GRD span2'. This procedure is shown in Figure 1:

Image Added

Figure 1 - Haunched steel-girder bridge

Create bridge deck sections

• Use the BrIM > Deck Section > Add Copy of Section

  " menu

  command to create bridge sections to be assigned to the first and the second spans of the bridge object.

  These sections will be named "SPAN1" and "SPAN2" and will utilize the previously defined nonprismatic girder sections "GRD span1" and GRD span2" as shown below:

Image Removed

Assign Bridge Deck Sections to the Bridge Object

• Use "BrIM

  Name these sections SPAN1 and SPAN2. Specify the previously-defined non-prismatic girder sections 'GRD span1' and 'GRD span2', as shown in Figure 2:

Image Added

Figure 2 - Deck section definition

Assign bridge deck sections to the bridge object

• Use the Bridge > Bridge Objects > Modify/Show Bridge Object > Modify/Show Assignments, Spans

  " menu

  command to assign the previously-defined bridge deck sections

  "

  SPAN1

  "

  and

  "

  SPAN2

  "

  to the bridge object spans 1 and 2, as shown in Figure 3:

Image Modified

...

Figure 3 - Deck section assignment

• Select the View > Set Display Options > Show Extruded Shape

  "

  option to display the extruded shape of the bridge, as shown in Figure 4:

Image Modified

Figure 4 - Steel girder bridge

See Also

• List of bridge modeler tutorials
• List of bridge tutorials

Attachments

• File | filename = Haunched steel girder bridge SAP2000 V12.0.2 file.zip | title = SAP2000 V12.0.2 model (Zipped SDB file)

  Steel-girder bridge with variable flange thickness tutorial

• Multiple sections within a single span article

Metadata

• Name: Haunched steel-girder bridge

• Description: Guidelines and tutorial for modeling haunched steel-girder bridges.

• Program: SAP2000

• Program Version: 12.0.2

• Model ID: na