Response Spectrum Wizard : ASCE 7 (05, 10), IBC (2006, 2009, 2015)

The ASCE 7-05 / ASCE 7-10 spectrum is defined by a set of parameters defined in the code. The IBC 2006 and IBC 2009 codes refer directly to the ASCE 7-05 code. The IBC 2015 code refer directly to the ASCE 7-10 code.

Site Class

Sites are classed as one of A, B, C, D or E depending on the soil. Type F soil requires specialist geotechnical advice and is not included as an option.

and

These are the short period response acceleration parameter and the 1s response acceleration parameter as defined in section 11.4.3. Seismic Hazard maps for the USA are available from the U.S. Geological Survey web site by following the USGS hyperlink.

Occupancy Category

The occupancy category from Table 1-1 is used to define the seismic design category (Tables 11.6-1 and 11.6-2) and the importance factor (I) (Table 11.5-1).

Response Modification and Deflection Amplification Factor

The response modification factor (R) and deflection amplification factor (Cd) are determined from Table 12.2-1 and section 12.9.2.

Frame Type and Building Period Coefficient

The approximate fundamental period of the building (section 12.8.2.1) is calculated from equation (12.8-7)

The building period coefficient, , depends on the type of building frame. The frame types are:

• Steel moment-resisting
• Reinforced concrete moment-resisting
• Eccentrically braced
• Other

And is the height of the building (in feet).

Ignore Short Period Force Reduction

It may be unconservative to reduce spectral values for low periods. This option ignores the reduction and extends the plateau to cover the low periods.