Loads Tab

This tab is where you input all the load information. Note that the screen will appear differently depending on the design code selected on the Project tab, as shown in Figure 1 and Figure 2. Data entry is the same for both codes except for the live load entry.

Figure 1 Loads Tab Screen (LFD)

Precast/Prestressed Girder now supports the input of Trapezoidal Load either on precast or on composite. A user can enter the start and end magnitudes (in klf), as well as start and end distances along the precast length over which the trapezoidal load acts.

Figure 2 Loads Tab (LRFD)

Based on the geometry information, Precast/Prestressed Girder automatically computes dead loads due to self-weight of girders, haunch and slab, and supplemental self-weight, and treats them as DC (Dead Load of Components) type loads.

Note: If Simple Span was selected on the Project tab screen, the Spans list will be grayed out under the permanent load list.

Input the required load data directly in the grid. The grid features the first level of data validation and any incorrect entries are flagged for the user's attention by turning red. Use the utility buttons such as Insert Row, Copy Row and Delete Row to enter/modify the remaining load information. You can modify the value for any particular load by directly editing the values in the grid. Modify a load by highlighting it, making the changes accordingly, and clicking Modify. To delete a load from the list, highlight it and click Delete.

In Precast/Prestressed Girder, you can copy a specific permanent load to any span and/or beam by clicking Copy To. This will activate the Copy To... screen, as shown below. You can either copy the selected load to a specific span and/or beam or copy it to all spans and/or all beams.

Figure 3 Copy To

To copy to a specific span and/or beam, select it from the appropriate list. To copy the load to all spans and/or beams, select the All Spans and/or All Beams check boxes. Once you made the selection, click OK. Any copied loads will appear in the permanent load list on the Loads screen. You can view all the loads on all spans by selecting the All Spans check box.

Under Diaphragm, you can manually input diaphragm loads as concentrated loads on specific beams, as follows:

Select a span from the Spans list.
Select a beam from the Beams list.
Specify the diaphragm’s location and load for that span in the Loc and Load fields.
Click Add. The load will appear in the list under Diaphragm.
Repeat the above steps to add additional diaphragm loads or use Copy To to copy the diaphragm load to other beams and/or spans. Click Copy To to activate the Copy To screen, as shown before.

Alternatively you can use the Permanent Load Wizard, as shown in figure below, to specify the most commonly defined loads in a simple way. Click Wizard to activate the Permanent Load Wizard. The program will classify the user input loads into the appropriate categories, such as DL/ADL or DC/DW, precast or composite, and add them to the Permanent Loads Grid for all spans in the bridge. Although Precast/Prestressed Girder generates loads on precast that are the same for interior and exterior beams, you can manually edit the values after they are populated in the grid. Similarly, you can control the distribution of the dead loads on composite using the distribution factors for each beam. The description field will also get populated based on the load type from the Wizard.

Figure 4 Permanent Load Wizard

Note: A description text tag can be appended to each dead load under the description field in the dead loads grid.

By checking the Keep Values option you can retain the values in the Wizard the next time you come back to the screen. This may be helpful in cases where you do not want to make any changes to the predefined load categories. You will not be able to edit the values in the dead load grid when this option is checked, however, you can add additional items in the grid.