Document: NUREG-0800
Document ID: 73747cf4-ff95-449b-b6b0-53dc0755b9e0
Document Type: srp
Title: OTHER SEISMIC CATEGORY I STRUCTURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1235/ML12353A382.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.8.4
CFR Part: 
CFR Title: 

Content:
ic solution by Wood (1973). This method assumes linear elastic strains in a homogeneous soil mass, a rigid wall with fixed base supported on stiff soil, and no displacement or sliding of the wall base relative to the underlying soil. Soil dynamics and wave propagation effects in the soil-wall system are also not considered. These assumptions may not be satisfied, for example, in the case of massive structures in deep soil sites where rocking could be important. 3.8.4-12 Draft Revision 4 – December 2012 Nevertheless, for cases where the assumptions of Wood’s solution are realistic, the method yields conservative estimates of the dynamic pressures. To account for a broad range of kinematic conditions, heterogeneity of the soil, as well as soil dynamics and wave propagation effects, a second method should be included based on soil-structure interaction (SSI) analysis of an embedded SSI/FEM model, as described in SRP Section 3.7.2. A limitation of such analysis is that it also assumes linear (or equivalent-linear) elastic strains in the soil. Therefore, a third method based on passive pressure should also be included to account for potential inelastic strains. The staff reviews the validity of the assumptions that are the basis of each of these three methods and the extent to which they correspond to the actual site conditions. In particular, the staff reviews the SSI/FEM model used in method (2) to ensure it is appropriate to this type of application. If other effects such as structure-soil-structure interaction are important, these should be included in addition to the pressures computed using the methods described above. If these methods are shown to be overly conservative for the cases considered, then the staff reviews alternative methods on a case-by-case basis. For earth retaining walls that are not restrained by a building, the guidance in ASCE 4-98 Sections 3.5.3.1 through 3.5.3.3 is acceptable. I. The design of masonry walls is considered acceptable when