AD.2007-1001.1.14 IBC 2006 Equivelant Lateral Force Procedure
The static equivalent method for performing dynamic analysis per the IBC 2006 code has been implemented in STAAD.Pro 2007 Build 02.
This option can be accessed from the General | Load page as explained below.
When the General | Load Page is selected, the right hand side of the screen will display the following if no load cases exist in the model.
Definitions contains the options through which one creates the "Define" block of data required to create wind load cases, seismic load cases like IBC and UBC, moving load cases and time history load cases.
When the tree view is expanded, it will look as shown below.
Select Seismic Definitions and click on Add.
In the dialog box that comes up, select IBC 2006 from the drop-down list.
In this dialog box, we can specify the various parameters as described below.
- Include Accidental Torsion
- Check this box to calculate the accidental torsion component described in section 184.108.40.206 of ASCE 7-05.
- The various parameters for the IBC 2006 code, such as the Occupancy Importance factor IE, Response modification factors RX and RZ, spectral response accelerations SDS, SD1 and S1, etc., are described in detail in TR.31.2.13 IBC 2006/2009 Seismic Load Definition.
After specifying the values for the parameters, click on the Add button.
We will see that the Load dialog box has now been updated.
Next, we should define the structural weights for calculating Base Shear.
After highlighting the expression LAT 38.0165……, click on Add. A new dialog box titled Add New Seismic Definitions will come up.