Document: NUREG-0800
Document ID: 215ec1da-bdbb-48d3-b871-6010c1f4bc55
Document Type: srp
Title: SEISMIC SUBSYSTEM ANALYSIS REVIEW RESPONSIBILITIES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1319/ML13198A239.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.3
CFR Part: 
CFR Title: 

Content:
ehavior of the dam material under design ground motion loadings, SSI effects, and nonlinear stress-strain relations for the soil, should be used. Analysis of earthen dams is reviewed under SRP Section 2.5.5, “Stability of Slopes.” 14. Methods for Seismic Analysis of Above-Ground Tanks. Most above-ground fluid- containing vertical tanks do not warrant sophisticated, finite element, fluid-structure interaction analyses for seismic loading. However, the commonly used alternative of analyzing such tanks by the "Housner-method" described in TID-7024 may be inadequate in some cases. The major problem is that direct application of this method relies on the assumption that the combined fluid-tank system in the horizontal impulsive mode is sufficiently rigid to justify the assumption of a rigid tank. For flat-bottomed tanks mounted directly on their bases, or tanks with very stiff skirt supports, the assumption leads to the usage of a spectral acceleration equal to the zero-period base acceleration. Studies by Veletsos (1974 and 1984), Veletsos and Yang (1977), Veletsos and Tang 3.7.3-8 Revision 4 – September 2013 (1989), and Haroun and Housner (1981), have shown that for typical tank designs, the frequency for this fundamental horizontal impulsive mode of the tank shell and contained fluid is such that the spectral acceleration may be significantly greater than the zero- period acceleration. Thus, the assumption of a rigid tank could lead to inadequate design loadings. The SSI effects may also be very important for tank responses, and they may need to be considered for both horizontal and vertical motions. The acceptance criteria below are based upon the information contained in TID-7024 and NUREG/CR-1161. Additional guidance is provided in ASCE Standard 4-98, Section 3.5.4. These references also contain acceptable calculation techniques for the implementation of these criteria. The use of other approaches meeting the intent of these criteria can also be considered if