Function
Define response modification factor for seismic design member forces in bridge piers. In AASHTO LRFD Bridge Design Specifications, the Response Modification Factor (R) is used to determine the seismic design forces by reducing the elastic response spectrum forces to account for the structure’s ductility and energy dissipation capacity. The R-factor varies depending on the type of bridge component and its ductility characteristics.
This feature allows for the application of different response modification factors based on substructure types and force components, i.e. moment and shear force.
Call
From the main menu, select [Design] tab > [Type : RC Design] > [Data Input Data] group > [Design Parameters] > [Response Modification Factor]
Input
Select a beam member from the Model View to enter the following factors:
Option
Add/Replace : Add a new value or modify a predefined value.
Delete : Delete a predefined value
Response Modification Factor
Fx: Enter the factor to reduce the axial force of the elastic response spectrum forces.
Fy: Enter the factor to reduce the shear force (y-dir.) of the elastic response spectrum forces.
Fz: Enter the factor to reduce the shear force (z-dir.) of the elastic response spectrum forces.
Mx: Enter the factor to reduce the torsion of the elastic response spectrum forces.
My: Enter the factor to reduce the moment about the y-axis of the elastic response spectrum forces.
Mz: Enter the factor to reduce the moment about the z-axis of the elastic response spectrum forces.