Document: NUREG-0800
Document ID: cc917e0f-066b-4749-a375-20ac6aeb97d5
Document Type: srp
Title: -
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1235/ML12353A354.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.2
CFR Part: 
CFR Title: 

Content:
Draft Revision 4 - December 2012 C. Nonlinear soil behavior. D. Coupling between the structures and soil. E. Lack of uniformity in the soil profile, which is usually assumed to be uniformly layered in all horizontal directions. F. Effects of the flexibility of soil/rock. G. Effects of the flexibility of basemat. H. The effect of pore water on structural responses, including the effects of variability of ground-water level with time. I. Effects of partial separation or loss of contact between the structure (embedded portion of the structure and foundation mat) and the soil during the earthquake. The procedures by which strain-dependent soil properties (damping, shear modulus, pore pressure development), layering, and variation of soil properties are incorporated in the analysis are reviewed. Assumptions for modeling the soil-structure system and computer program validation documents are also reviewed. If applicable, the criteria for determining the location of the bottom boundary and side boundary of the soil-structure system model are reviewed. The procedures used in the SSI analysis to account for effects of adjacent structures, if any, on structural response are reviewed. To perform a seismic analysis for an SSI system, it may be necessary to have well- defined excitation or forcing functions applied at the model boundaries to simulate the design earthquake ground motion. It is therefore required in such cases to generate an excitation system acting at the boundaries such that the response motion of the soil media at the plant site in the free field is identical to the design earthquake ground motion. The procedures and theories for regeneration of such an excitation system are reviewed. Any other modeling methods used for SSI analysis are also reviewed, as is any basis for not using an SSI analysis. For a DC application, the number and characteristics of generic site profiles are reviewed to ensure there is an adequate seismic design basis for a standard plant.