Define the general layout of the bridge.

Item	Description
Bridge Line Offset	Enter the offset from the alignment to the bridge line.
Girder Family	Select a general type of girder from the drop down list
Girder Type	Select a specific type of girder. Check the box below the list if this girder type is to be used for the entire bridge.
Number of Girders	Use the up/down arrows to select the number of girders. Check the box below if this number of girders is to be used in all spans.
Location of Girder Working Points	Specify the vertical location along the CL girder where girder spacing is to be measured; aka, the working point location. The default working point location is at the top CL of girder. However, many girder types allow girder spacing to be measured at the bottom CL girder.
Spacing Type	Select the spacing type to be used
Girder Spacing	Enter the girder spacing, locate the girders transversely, and select the measurement datum. See Bridge Modeling in the User Guide and Girder Spacing in the Technical Guide for additional details.
Joint Spacing	Enter the joint width between adjacent girders, locate the girders transversly, and select the measurement datum. See Bridge Modeling in the User Guide and Girder Spacing in the Technical Guide for additional details.
Top Width	Select a top width type and enter the top width dimensions. Top width types are Symmetric (the top flange is symmetric about the centerline of the girder), Centered CG (the length of the top flange on the left and right side of the girder centerline are automatically computed such that the center of gravity of the girder is coincident with the girder centerline), and Asymmetric (the top flange is asymmetric and defined by unique left and right overhangs measured from the girder centerline).
Girder Connectivity	For adjacent girders, select the transverse connectivity. The girder connectivity influences the live load distribution factor calculations.
Girder Orientation	Select the girder orientation datum for all girders in the bridge. Orientation can be set plumb; oriented such that top flanges are parallel the roadway surface at the start, middle, or end of spans; or the orientations can be balanced to minimize the haunch depth at both ends of each girder.
Deck Type	Select the type of deck to be used

A description of the bridge, along with the assumed cross section type for live load distribution factor calculations, is given.

Bridge Line

The Bridge Line is an arbitrary line that parallels the alignment. This line can represent anything, though it is most commonly used for the centerline of the bridge. Many of the bridge geometry parameters, such as transverse location of girders and the edge of deck, can be located by an offset from the Alignment or the Bridge Line.

Deck Type

The list of deck types depends of the girder family and spacing type.

Deck Type	Description
Composite Cast-In-Place Deck	The deck is a composite, cast in place concrete deck. The plan view deck geometry is defined by a sequence of station and offset parameters on the Deck Geometry and Materials tab.
Composite Stay-In-Place Deck Panels	The deck is constructed of partial depth stay in place concrete deck panels and a cast in place topping. This deck system is composite with the girder. The plan view deck geometry is defined by a sequence of station and offset parameters on the Deck Geometry and Materials tab.
Composite Cast-In-Place Overlay	This deck type is a composite, cast in place concrete deck used with adjacent girders. The plan view deck geometry is defined by the overall perimeter of the girders.
Nonstructural Overlay	This deck type is a cast in place concrete overlay used with adjacent girders. The plan view deck geometry is defined by the overall perimeter of the girders. This deck type serves as a wearing surface and contributes dead load to the structure, however it is nonstructural so it does not contribute to the capacity of the structure.
No Deck	Use this option when roadway surface is integral with the girder elements. Examples of this include adjacent voided slabs, box beams, and deck bulb tee girders.

More Information

The general layout of the bridge defined in this window is for a simple, uniform bridge with the same type of girder in all spans and the same girder spacing in all spans. More complex bridges can be defined. Each girder can be a different type, though all girders must be in the same family. That is, for example, you can use several different types of slab girders in a span, but you cannot mix slab girders with other girder types. Each span can also have a unique number of girders and unique girder spacing. See the following for additional information:

User Guide - Bridge Modeling