Document: NUREG-0800
Document ID: 8160c1fd-7cef-4c93-8e12-456019f2cfd2
Document Type: srp
Title: FOUNDATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1319/ML13198A267.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.8.5
CFR Part: 
CFR Title: 

Content:
ubsection II.4.E of SRP Section 3.8.1. In addition to the above, the design and analysis procedures for the following details are reviewed on a case-by-case basis: A. Appropriateness of the method for determination of the bending moments and shear forces in the mat foundation for seismic loads. B. Adequacy of the sliding analysis method and the analysis results to account for potential mat foundation liftoff effects. The staff should also review the calculation of the factor of safety against sliding. If sliding resistance is the sum of shear friction along the basemat and contribution of soil lateral pressure up to the full passive pressure capacity induced by embedment effects, the adequacy of the analysis to consider these effects is addressed using a consistent lateral displacement criterion. This involves the use of static versus dynamic coefficient of friction consistent with the use of partial versus full passive pressure. The reviewer shold also consider whether the selection of the coefficient of friction used in the sliding stability analysis considers the various sliding interfaces (e.g., soil shear failure, concrete to soil, waterproofing to soil, concrete basemat to concrete mudmat). If the stability evaluation is performed based on a pseudo-static approach, using the maximum seismic demand loads (e.g., maximum forces in the two horizontal directions and one vertical direction), then the factors of safety for sliding and overturning can be determined by the ratio of capacity to demand loads. However, if a linear time history analysis approach is utilized, then the factor of safety can be calculated at each time step throughout the time history. The minimum value of the factors of safety calculated in this manner should be compared against the acceptance criteria for that load combination. For the pseudo-static and time history analysis methods, all three directional demand 3.8.5-10 Revision 4 – September 2013 forces should be considered to act