M. To add a GB 50011-2010 response spectrum
To specify a response spectrum for seismic loading per the Chinese GB 50011 2010 (2016 edition) code, use the following procedure.
Tip: This will add the load item to the currently selected load group selected in the program status bar.
- Select the Response Spectrum tab.
- Select Chinese GB 50011 - 2010 in the Code list.
- Select the Combination Method to use to combine the responses from each mode into a total response. The CQC and SRSS methods are available for the GB 50011-2010 response spectra.
Specify the GB 50011-2010 specific parameters:
- Select a Fortification Intensity, Seismic Frequency, and Site Class (SCL) for the location.
- Select the Seismic Group appropriate for the structure.
Select if the
Interpolation Type is
The logarithmic option is recommended when only a few spectra data points are entered, as spectra vs period curves are typically only linear on a log-log scale.
- Select the Damping Type to use and, if explicit Damping is selected, type the damping ratio to be used for all modes.
- Select the directions which spectrum is applied and for each, type a factor (0-1.0).
You can apply each of the following optional steps as needed:
Select one of the
Signed Response Spectrum Results Options
check Dominant and type a Mode No to use for determine the signs of all modes. You can alternatively type 0 for the Mode No to have the program select the mode with the greatest percent participation in the excitation direction for the dominant mode.
- Check the Missing Mass option to include the static effect of masses not represented in the modes. Type an optional spectral acceleration for this missing mass mode.
- If the Missing Mass option is used and you want to specify an acceleration corresponding to a frequency instead, check the ZPA option and type a frequency. If neither the missing mass acceleration value or ZPA frequency is specified, then the spectral acceleration at 33Hz is used to calculate the missing mass mode.
- Select one of the Signed Response Spectrum Results Options if needed:
- Click Add. The new response spectrum is added to the currently selected load case.