ML24292A061
| ML24292A061 | |
| Person / Time | |
|---|---|
| Issue date: | 10/18/2024 |
| From: | Jinsuo Nie, Jose Pires NRC/RES/DE |
| To: | |
| Thomas Weaver 301-415-2383 | |
| Shared Package | |
| ML24292A057 | List: |
| References | |
| Download: ML24292A061 (1) | |
Text
Abstract Due August 2 The Power Journey - A Cursory Account of the Recent History of Power Spectral Density Functions in Seismic Input Motion Development Jinsuo Nie and Jose Pires Division of Engineering Office of Nuclear Regulatory Research Nuclear Regulatory Commission Seismic input motions are often necessary in developing in-structure response spectra, simulating foundation uplift and sliding, soil-structure analysis, fluid-structure analysis, advanced seismic fragility analysis, shake table testing, and general nonlinear analyses, among others. Seismic input motion development (SIMD) has a long history of practice using various methods. Often the motions have been developed so that, to overcome computational limitation or improve efficiency in seismic analysis and design, a minimal number of motions are used to represent the seismic hazard at a given site or a group of sites. The central parameter of seismic hazard is now represented generally as the design response spectra (DRS), which is the interface between the seismological community and the structural engineering community and a much-simplified term to represent various forms of response spectra such as uniform hazard rock spectra, foundation level input response spectra, or certified seismic design response spectra. Seismic input motions are developed to envelop the DRS, as well as in some practice, checked for the sufficiency of their power spectral density (PSD) functions.
However, PSD check is not uniformly applied in different practices and response spectrum (RS) matching remain the current dominating practice of SIMD. This presentation will cover a cursory account of the recent history of SIMD going back at least to the era of SIMQKE development, which rather than attempting to be a full literature review aims to attract contributions from the audience at or after the meeting. A recent convergence of the evolution of the seismic input motion acceptance criteria in U.S.
Nuclear Regulatory Commissions Standard Review Plan and the decades-long recognition, e.g. within the NEA/CSNI/WGIAGE Seismic Engineering Subgroup, that the peak ground acceleration and the DRS are incomplete indicators of the seismic input motion damaging capacity, provides an opportunity for a broad discussion on how to adequately and efficiently develop seismic input motions considering their use scenarios as well as on the feasibility of including PSD in the seismic hazard characterization and directly in seismic analysis and design. This discussion is becoming more urgent as seismic time history analysis becomes more popular to take advantage of enhanced computational availability and to tackle new design concepts. This discussion is also relevant as a knowledge transfer activity to the next generation of engineers that are expected to use newer analysis and computational tools that would likely lead to an increasing use of time-history analyses.