Parameters of a structure seismic analysis depend on a seismic code used during calculations of a structure influenced by seismic impact. Select Chilean Code in the New Case Definition dialog or click Parameters in the Analysis Type dialog.
To perform seismic analysis according to the rules specified in this code, define the following parameters:
- Seismic zone number
- Soil type
- Structure category
- Direction
- Value of the Ro modification coefficient.
In the lower part of the dialog, the Direction definition and Filters buttons are located.
Horizontal base shear:
Q0 = C * I * P,
where:
- C - Coefficient given by the following formula:
n, T' - parameters relative to the foundation soil type (see tables 1 and 2 of the code)
A0 - maximum effective acceleration (see table 3 of the code):
Seismic zone = 1, A0 = 0.20g
Seismic zone = 2, A0 = 0.30g
Seismic zone = 3, A0 = 0.40g
R0 - reduction factor (see table 4 of the code)
T* - period of mode with the highest translational equivalent mass in the direction of analysis
- I - Coefficient of importance (see tables 5 and 6 of the code)
- W - Total weight of the building above the base level.
The details concerning this structure analysis method can be found in the mentioned code.