{{Tutorial

...

This tutorial describes the modeling process for a composite bridge composed of a concrete slab over steel girders that have with variable flange thickness.

On this page:

Modeling

...

steps

To obtain the variable flange thickness desired, users should assign non-prismatic girder sections to the bridge deck section to obtain the desired variation of flange thickness.

Create

...

a new model from template

• Select File > New Model

  ", select "

  > KN, m, C

  "

  units

  and

  > Quick Bridge 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

  "

  
  
  

  • rename

    Rename the default girder section

    "

    FSEC1

    "

    to

    "

    'GRD 50mm

    FLANGE"create copy of "GRD 50mm FLANGE"

    Flange'.

  • Copy the 'GRD 50mm Flange' section, change the thickness for the top and bottom flanges to 75mm

    and

    , change the section depth to 1.27m (

    to keep the

    maintaining consistency with previous web depth

    the same as for the previous section

    ), and then save the section as

    "

    'GRD 75mm

    FLANGE"create nonprismatic sections "GRD span1" and "GRD span2" (via "Add New Property" button, frame section property Other and nonprismatic section)

    Flange'.

  • Select Add New Property > Frame Section Property (other) > Non-prismatic Section to create non-prismatic sections 'GRD span1' and 'GRD span2' as follows: (1) for

    "

    'GRD span1

    "

    ', specify the

    "

    'GRD 50mm

    FLANGE"

    Flange' section for the first 20m of length

    of the section and "

    , and the 'GRD 75mm

    FLANGE"

    Flange' section for the next 10m of length

    of the section

    ; (2) for

    "

    'GRD span2

    "

    ', specify the

    "

    'GRD 75mm

    FLANGE"

    Flange' section for the first 10m of length

    of the section and "

    , and the 'GRD 50mm

    FLANGE"

    Flange' section for the next 20m

    length of the section

    of length. This process is shown in Figure 1:

Image Modified

...

Figure 1 - Section definition

Create bridge deck sections

• Use

  "

  the Bridge > 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

  Name these sections SPAN1 and SPAN2, and utilize the previously-defined

  nonprismatic

  non-prismatic girder sections

  "

  'GRD span1

  "

  ' and 'GRD span2

  "

  ', as shown

  below

  in Figure 2:

Image Modified

Assign Bridge Deck Sections to the Bridge Object

...

Figure 2 - Bridge section data

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 first and second spans of the bridge object

  spans 1 and 2

  , as shown in Figure 3:

Image Modified

Figure 3 - Span assignments

• Set OpenGL graphics

  via "

  using the Option > Graphics Mode > OpenGL

  "

  menu command

• Go to "

  Use View > Set Display Options > Show Extruded Shape

  "

  to display the extruded shape of the bridge

  (

  . Please note that there is a

  slight

  graphical

  display issue

  discontinuity,

  but

  though the frame elements are inserted such that

  the locations at the

  top-of

  the

  -web locations form a continuous line

  ; this can

  . This may be checked by reviewing the insertion point

  , which is

  (top center

  ,

  ) and offsets

  ):

...

• . The extruded view is shown in Figure 4:

Image Added

Figure 4 - Extruded view

See Also

• List of bridge modeler tutorials
• List of bridge tutorials

Attachments

• File | filename = Variable flange thickness steel girder bridge SAP2000 V14.0.0 file.zip | title = SAP2000 V14.0.0 model (Zipped SDB file)

...

• Multiple sections within a single span article

Metadata

• Name: Steel-girder bridge with variable flange thickness

• Description: Guidelines and tutorial for creating a steel-girder bridge with variable flange thickness.

• Program: SAP2000

• Program Version: 14.0.0

• Model ID: na