Document: NUREG-0800
Document ID: db865dc2-7652-4844-9a97-6ba02f1faa4b
Document Type: srp
Title: Seismic Wave Transmission Characteristics of the Site. In the PSHA
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0529/ML052910327.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.2.5
CFR Part: 
CFR Title: 

Content:
procedure described in Regulatory Guide 1.165 (Ref. 9), the controlling earthquakes are determined for actual or hypothetical rock conditions. The site amplification studies are performed in a distinct separate step as a part of the determination of the SSE. In this section, the applicant's site amplification studies are reviewed in conjunction with the geotechnical and structural engineering reviews. Particular emphasis is placed'on how the uncertainties inherent in this process are addressed. To be acceptable, the seismic wave transmission characteristics (amplification or deamplification) of the materials overlying bedrock at the site are described as a function of the significant frequencies (Ref. 13). The following material properties should be determined for each stratum under the site: thickness, seismic compressional and shear wave velocities, bulk densities, soil index properties and classification, shear modulus and damping variations with strain level, and the water table elevation and its variations (Ref. 14). In each case, methods used to determine the properties should be described in Subsection 2.5.4 of the SAR and cross-referenced in this subsection. Where vertically propagating shear waves may produce the maximum ground motion, a one-dimensional equivalent-linear analysis (e.g., Ref. 15 or 16) or nonlinear analysis (e.g., Refs. 17, 18, or 19) may be appropriate and is reviewed in conjunction with geotechnical and structural engineering. Where horizontally propagating shear waves, compressional waves, or surface waves may produce the maximum ground motion, other methods of analysis (e.g., Refs. 20 and 21) may be more appropriate. However, since some of the variables are not well defined and the techniques are still in the developmental stage, no generally agreed-upon procedures can be promulgated at this time. Hence, the staff must use discretion in reviewing any method of analysis. To ensure appropriateness, site response characteristics determined