Document: NUREG-0800
Document ID: 7aa298c9-0641-4a4c-8818-8fc9d3c721af
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 stiffness properties of the uncracked members by a reduction factor. Acceptable stiffness reduction factors for cracked concrete members are given in the ASCE/SEI 43-05 standard (e.g., 0.5 for cracked walls for flexure and shear). For the design of structures, the responses (e.g., member forces, displacements, soil bearing pressures) are typically determined from a separate detailed finite element analysis. The effects of concrete cracking in these finite element analyses should be considered in a manner consistent with the representation of cracking in the SSI analysis. Further guidance on whether cracked concrete properties should be considered in the design for seismic Category I structures is provided in the acceptance criteria for design and analysis procedures presented in SRP Sections 3.8.1 and 3.8.3 through 3.8.5. 2. Enhanced SRP Section 3.7.2 II.4 “Soil-Structure Interaction” by adding acceptance criteria related to foundation uplift. The technical rationale for this change is as follows. The seismic analysis used in the design of Seismic Category I structures requires consideration of the potential uplift of the foundation from the supporting soil media. Limiting the foundation uplift is necessary to ensure the validity of the SSI analysis that is based on linear methodologies. Consideration of foundation uplift is also important in order to appropriately estimate the overturning moments induced by the seismic input and the soil bearing pressures at the foundation toe. SRP Section 3.7.2 II.4 indicates that sensitivity studies are needed to identify the potential for separation and sliding of soil from sidewalls, among other issues, and to assist in judging the adequacy of the final results of the SSI analyses. SRP Section 3.8.5II.4.D provides guidance on how to define the dead load for uplift evaluations, including the treatment of the stored water in internal water pools inside the structures. Other SRP 3.8.5