Analysis Case Data - Moving Load Form

Access the Analysis Case Data - Moving Load form as follows:

Note: To analyze for vehicle live load, first define a layout line, a lane(s), a vehicle(s), vehicle class(es), a bridge load(s) and set the type of bridge response.

Click the Define menu > Analysis Cases command, or on the Bridge Wizard highlight the Analysis Cases item and click the Define/Show Cases button to display the Analysis Cases form.
Click the Add New Case button or highlight a previously defined analysis case and click the Add Copy of Case or the Modify/Show Case button to display the Analysis Case Data form.
Select Moving Load from the Analysis Case Type drop-down list to display the Analysis Case Data - Moving Load form.

After the bridge loads have been defined, define one or more moving-load analysis cases that assign the vehicles classes to the traffic lanes. The Analysis Case Data - Moving Load form is used to view and change the definition of a moving load analysis case.

Stiffness to Use Choose to solve for the response using the stiffness of the unstressed structure (i.e., the Zero Initial Conditions - Unstressed State option), or at the end of a nonlinear static or nonlinear direct-integration time-history analysis case (i.e., the Stiffness at End of Nonlinear Case option and drop-down list). See Stiffness to Use for more information. If you don't know what to do, choose the Zero Initial Conditions - Unstressed State option.
Load Applied Apply loads by specifying one or more lanes in which a vehicle class may operate. Every permutation of vehicle classes operating in traffic lanes that is permitted by the entries in this table will be considered in the analysis.

Assign Number display box. As loads are defined, the program enters an assignment number in this display box.
Vehicle Class drop-down list. Choose the vehicle class name, which was defined using the Vehicle Class Data form.
Scale Factor edit box. Enter a scale factor that multiplies the load for all vehicles in the class.
Min Loaded Lanes edit box. Enter the minimum number of lanes that must be occupied by the vehicle class. This is usually zero.
Max Loaded Lanes edit box. Enter the maximum number of lanes that may be occupied by the vehicle class. A value of zero indicates all lanes.

Add button. To add a live load to the set of applied loads, enter the vehicle class and other parameters at the top of the table, then click the Add button. After clicking the Add button, use the Add-> and <-Remove buttons in the "Lanes Loaded for Assignment {Number}" area of the form to create a list in the Selected Lanes column that indicates all of the lanes in which this vehicle class is allowed to operate. All permutations will be considered for the lanes that are between the minimum and maximum number of allowed loaded lanes.
Modify button. To modify a live load in the set of applied loads, click on the load in the table to select it, make any changes to the vehicle class and other parameters at the top of the table, or to the list of loaded lanes, then click the Modify button.
Delete button. To remove a live load from the set of applied loads, click on the load in the table to select it, then click the Delete button.

Lanes Loaded display box. The program will display All, Some, or None in this column to specify if lanes are involved in the applied load assignment. Use the following list boxes and buttons to modify the lane assignments to the applied load.

List of Defined Lanes. The lanes defined for the model are listed in this list box.
List of Selected Lanes. The lanes to be used in a particular load are shown in this list box.
Add and Remove buttons. Use these buttons to add lanes to or remove lanes from an applied load. Highlight the load in the Loads Applied area (e.g., click on the Assign Number), highlight a lane(s) in the List of Defined Lanes display box and click the Add button to move the selected lane(s) into the Selected Lanes display box, which adds the lane(s) to the applied load. To remove a lane(s) from the applied load, highlight the load in the Loads Applied area, highlight a lane(s) in the Selected Lanes display box and click the Remove button to move the selected lanes into the List of Defined Lanes list box, which removes the lane(s) from the applied load.

Multi-Lane Scale Factors parameter. For each number of loaded lanes, enter any scale factors that may apply. This does not apply to any specific lanes, but rather to combinations of loaded lanes. For example, you may want to set the scale factor to 1 for one or two loaded lanes, to 0.9 for three loaded lanes, and to 0.75 for four or more loaded lanes. These factors will be automatically applied when forming the various permutations of vehicle classes on the traffic lanes. Highlight data in the display list, enter a revised Reduction Scale Factor in the edit box, and click the Modify button to change a scale factor.