Evaluation of Seismic Demand (Response)

DOE-STD-1020-2002

exception that site-specific information may be used if appropriate to define the earthquake input

excitation used to establish seismic loadings (see Table C-6). The maximum ground acceleration

and ground response spectra determined in the manner defined in IBC 2000 are used in the

appropriate terms of the IBC 2000 equation for base shear. Use of site-specific earthquake

ground motion data is considered to be preferable to the general seismic zonation maps from the

IBC 2000 with limitations imposed in the IBC 2000 Code. IBC provisions require a static or

dynamic analysis approach in which loadings are scaled to the base shear equation value. In the

base shear equation, inelastic energy absorption capacity of structures is accounted for by the

parameter, R. Elastically computed seismic response is reduced by R values ranging from 1 to

8 as a means of accounting for inelastic energy absorption capability in the IBC provisions and

by these criteria for Performance Category 2 and lower SSCs. This reduced seismic response is

combined with non-seismic concurrent loads and then compared to code allowable response

limits (or code ultimate limits combined with code specified load factors). Normally, relative

seismic anchor motion (SAM) is not considered explicitly by model building code seismic

provisions.

DOE-STD-1020

Specified Hazard Probability of Exceedance

Natural Phenomena

to Get Peak Acceleration and Response

Hazards Design &

Spectrum

Evaluation Criteria for

DOE Facilities

Deterministic Evaluation of Response and

Capacity with Controlled Level of Conservatism

2002

C-19