Bridge Object In-Span Cross-Diaphragm Assignments Form

A diaphragm assignment includes a diaphragm location, property and orientation. The diaphragms assigned here are in-span diaphragms. Diaphragms that occur at abutments, bents and hinges are assigned as part of the bridge object abutment, bent, and hinge assignments, respectively. Although any diaphragm property can be assigned within a span, a concrete diaphragm will be used by the program only if it occurs within a span with a concrete deck section, and similarly, a steel diaphragm will be used by the program only if it occurs within a span with a steel deck section.

Use the Bridge Object In-Span Cross Diaphragm Assignments form to add diaphragms to selected spans of the bridge.

Bridge Object Name display box. This display box identifies the bridge object to which the diaphragm definition applies.
Units drop-down list. Use the displayed units or select new units from the drop-down list.
In-Span Cross Diaphragm Definition. Use the options in this area of the form to specify the span, the diaphragm property, its distance from the beginning of the span, the bearing for the diaphragm, and if the diaphragm applies to all of a span or on a girder-by-girder basis.
- Span drop-down list. Select the Span to which the diaphragm is being added.
- Diaphragm Property drop-down list. Select the property definition for the diaphragm. Alternatively, click the plus symbol (+) above the Diaphragm Property drop-down list to access the Define Bridge Diaphragm Properties form and define a new diaphragm or modify or delete an existing diaphragm.
- Location drop-down list. Use this drop-down list to specify the transverse location of the diaphragms.
- Bearing edit box. Use this edit box to specify the bearing (orientation) for the diaphragm, which applies to All Spaces and Girder j or girder j+1 Locations, For All Spaces location, the specified bearing orientation will force a matching section cut and the meshing will be aligned with this section cut.
The following information only applies for steel U girder bridge sections: The Bearing edit box is not editable for All Girder Interiors and individual girder interior locations. For the former location, the U girder interior diaphragms will be created aligned with the existing section cut at that location; for the latter location, the U girder interior diaphragm will be created perpendicular to the girder line.
- Distance edit box. Specify the distance of the diaphragm in the current length units from the beginning of the span. The distance is measured either along the span layout line or the individual girder length depending on the assigned Location described above and the Ref Line described below.
- Ref Line drop-down list. Use this drop-down list to specify the reference line for measuring distance.

With selections and entries have been made in the preceding drop-down lists or edit boxes, click the Add button to add the diaphragm definition. Highlight a previously defined definition, make the necessary changes and then click the Modify button to update the definition. Highlight a previously defined definition and click the Delete button to remove the highlighted definition.

Access the Bridge Object In Span Cross Diaphragm Assignment form as follows:

At a minimum, create a Layout Line and define a Deck Section.
Click the Bridge > Bridge Objects > Expand arrow, or on the Bridge Wizard select the Bridge Object Definition item and click the Define/Show Bridge Object button, to display the Define Bridge Objects form.

Alternatively, bypass the Define Bridge Objects form by clicking the Bridge > Bridge Objects > New command and go directly to the Bridge Object Data form identified in the next step.

Click the Add New Bridge Object button, or highlight a previously defined bridge object definition and click the Add Copy of Bridge Object or the Modify/Show Bridge Object button, to display the Bridge Object Data form.
In the Modify/Show Assignments display list, highlight the In-Span Cross Diaphragms item and click the Modify/Show button to display the Bridge Object In Span Cross Diaphragm Assignment form.

Alternatively, on the Bridge Wizard select the Diaphragms item in the Bridge Object Assignments area and click the Assign/Show Diaphragms button to access the Bridge Object In Span Cross Diaphragms Assignments form.