Ground motion selection for simulation‐based seismic hazard and structural reliability assessment

Abstract

This paper examines four methods by which ground motions can be selected for dynamic seismic response analyses of engineered systems when the underlying seismic hazard is quantified via ground motion simulation rather than empirical ground motion prediction equations. Even with simulation-based seismic hazard, a ground motion selection process is still required in order to extract a small number of time series from the much larger set developed as part of the hazard calculation. Four specific methods are presented for ground motion selection from simulation-based seismic hazard analyses, and pros and cons of each are discussed via a simple and reproducible illustrative example. One of the four methods (method 1 'direct analysis') provides a 'benchmark' result (i.e. using all simulated ground motions), enabling the consistency of the other three more efficient selection methods to be addressed. Method 2 ('stratified sampling') is a relatively simple way to achieve a significant reduction in the number of ground motions required through selecting subsets of ground motions binned based on an intensity measure, IM. Method 3 ('simple multiple stripes') has the benefit of being consistent with conventional seismic assessment practice using as-recorded ground motions, but both methods 2 and 3 are strongly dependent on the efficiency of the conditioning IM to predict the seismic responses of interest. Method 4 ('GCIM-based selection') is consistent with 'advanced' selection methods used for as-recorded ground motions, and selects subsets of ground motions based on multiple IMs, thus overcoming this limitation in methods 2 and 3.

Effect of ground motion selection methods on seismic collapse fragility of RC frame buildings

“…[29,30]). Since the introduction of UHS, it has been the primary method by which GM records are selected and scaled.…”

Markov chain Monte Carlo ground‐motion selection algorithms for conditional intensity measure targets

“…For now, we strongly recommend preselection as an effective way to improve computational efficiency without sacrificing accuracy. However, we also suggest that caution be applied in the future as the numbers of records increases or as simulated records become considered . For the NGA West database used herein in case 2, the range of PDF values varied from 4.35 × 10 −16 to 7.07 × 10 7 .…”

“…Thus far it has been implicitly assumed that obtaining a more accurate match to the target distribution (as measured by the similarity of moments) leads to more accurate estimates of the response distribution. In the present section, selected records sets are passed through a nonlinear single degree‐of‐freedom (SDOF) system similar to that used by Bradley et al …”

“…However, we also suggest that caution be applied in the future as the numbers of records increases or as simulated records become considered. 47 For the NGA West database used herein in case 2, the range of PDF values varied from 4.35 × 10 −16 to 7.07 × 10 7 . As databases become more complete, then more records will have PDF values above the threshold corresponding to the median that was used in the present study.…”

On the Seismic Design of Structures with Tilting Located within a Seismic Region

“…There are several methods in the literature to estimate the reliability of structures. For example: (a) the semi-probabilistic [24], (b) first order and second moments (FOSM) [25][26][27], (c) load and resistance factors design (LRFD) format [28,29], (d) those based on seismic hazard or risk analysis [30][31][32][33][34], and (e) those based on optimization [35][36][37][38]. In the present study, the structural reliability is evaluated by means of seismic hazard analysis.…”