Auto Load Generation EQ Screen
This screen is used for auto generating earthquake loads. These loads are obtained from single-mode spectral analysis. Note that the screen shown is CHBDC .
- Start by entering the values in the Acceleration Coefficients (PGA,S1,Ss) selecting Site Class Type.
- Input the bridge layout information. Select the importance classification from the list and input the moment of inertia of superstructure about the global X and Y-axis. The program automatically calculates unit weight and cross-section area of superstructure based on available superstructure data. You can modify these values if needed. Program computes zone number based on acceleration coefficient SD value as per criteria defined in . Note that auto generation only supports SM that is single mode spectral method. Click Help to verify applicability of SM method as per Table 4.1 .
- You can modify the span length under Span Data by highlighting the span #, entering a new value in the Span Length field, and clicking Modify.
- Enter the required information under Pier-Col Data. You must input the total moment of inertia and total area for all columns, about the global X, Z directions, for each pier. For example, if a pier has three columns, Iz will be the sum of the moment of inertia about Z-axis from these three columns, or Area will be the sum of that of each column.
Note: The default values for Iz, Ix, and Area are already provided in the fields under Pier-Col Data. These values are calculated on the assumption that all other piers in the bridge considered has the same number and size of columns, as those of the current pier under consideration.
To modify these values under Pier-Col Data, highlight the desired pier in the list, make the appropriate changes, and click Modify.
Once you entered all required information on the screen, click Generate. The program will automatically generate the loads and return to the Loads: Load Data screen.