Content Comparison

Lanes can be defined using one of the following two approaches:

* from frame elements
* from [layout lines|layout line]

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h1. Lanes defined from frames

For lanes defined from frame elements, the moving load is applied directly to the frame elements that were used to define the lane. This true for zero-width lanes as well as nonzero-width lanes. If the lane was defined with an eccentricity relative to the frame element, the program accounts for this eccentricity by applying torsional moment that is equal to the moving load times the eccentricity, as described in more detail in the following section.

h2. Eccentric load applied to lanes defined from frames

When an eccentric vertical load is applied to a lane defined from frame elements, SAP2000 will apply this eccentric load directly to the frame element that was used to defined the lane using the vertical load and torsional moment (to account for the eccentricity) as follows:

* The vertical load is applied at the centerline of the frame element at the location that corresponds to the intersection of the frame centerline and a line perpendicular to this centerline and passing through the location of the eccentric load.
* Torsional moment is calculated as a product of the vertical load magnitude and its transverse eccentricity from the centerline of the frame. This torsional load is applied at the same location as the vertical load described above.

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Related incidents and emails:

* {incident:no=30603|comment=Applying eccentric loads to lanes defined from frames}
* {email:date=12/27/2010|from=ok|to=me|subject=Applying eccentric loads to lanes defined from frames|comment=Description of the procedure|id=6357715}
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h1. Lanes defined from layout lines

For lanes defined from layout lines, the program uses the concept of [lane loading points|Lane-load point] and [structural connections|kb:Lane loading point structuralLane-to-object connection] as follows: Based on the lane discretization, the program creates lane loading points along the width and length of each lane in the model. Then it places unit load in gravity direction at each lane loading point to determine the deflected shape. The unit load applied to the lane loading point is proportionally distributed to the tributary joints in the model. Using "Display > Show Lanes > Show Structural Connection For Selected Point" you can display the connections between the lane loading point and the joints in the model. Lanes defined from layout lines were available up to SAP2000 V14 and required the bridge license. They are no longer available in SAP2000 V15, because they were "moved" to the CSiBridge program, which is essentially the successor of the bridge modeler in SAP2000.