Sliding and Rocking of Unanchored Components and Structures: Chapter 7.6 ASCE 4 Revision 2

Section 7.6 of ASCE 4-Rev 2, Seismic Analysis of Safety-Related Nuclear Structures: Standard and Commentary, provides updated guidance for analysis of rocking and sliding of unanchored structures and components subjected to seismic load. This guidance includes provisions both for simplified approximate energy-based approaches, and for detailed probabilistic time history analysis using nonlinear methods. Factors to be applied to the analytical results are also provided to achieve demand estimates at the 80% non-exceedance probability level. The present paper surveys the published literature supporting these provisions. The results of available testing and analyses are compared to results produced by both simplified and probabilistic approaches. In addition, adequacy of the standard's provisions for analysis methods and factors is assessed. A comparison is made between the achieved level of conservatism and the standard's non- exceedance probability target.