A Computationally Efficient Ground-Motion Selection Algorithm for Matching a Target Response Spectrum Mean and Variance

Abstract

Dynamic structural analysis often requires the selection of input ground motions with a target mean response spectrum. The variance of the target response spectrum is usually ignored or accounted for in an ad hoc manner, which can bias the structural response estimates. This manuscript proposes a computationally efficient and theoretically consistent algorithm to select ground motions that match the target response spectrum mean and variance. The selection algorithm probabilistically generates multiple response spectra from a target distribution, and then selects recorded ground motions whose response spectra individually match the simulated response spectra. A greedy optimization technique further improves the match between the target and the sample means and variances. The proposed algorithm is used to select ground motions for the analysis of sample structures in order to assess the impact of considering ground-motion variance on the structural response estimates. The implications for code-based design and performance-based earthquake engineering are discussed.

Simplified Prediction of Peak Floor Accelerations in Inelastic Wall Structures

“…Therefore, a broad class of buildings located in Century City can be assessed (or designed, respectively) by this record set without conducting record selection with respect to the fundamental period of every individual structure seperately. This record selection procedure can be seen as an alternative to the existing body of conditional mean spectrum (CMS) methods [17,18]. Figure 6 shows the target spectra (bold black lines), the 92 individual response spectra (gray lines), and the corresponding statistical quantities (thin black lines) of the Century record set, which will be used for analyses in the remainder of this paper.…”

Performance Based Earthquake Engineering Approach Applied to Bridges in a Road Network

“…In the present work the conditional spectrum method [12], a recently proposed selection and scaling procedure, recently employed with success in bridge assessment studies [19], has been employed for the selection of nine records, considered with the two horizontal and vertical components, as seismic input. To accomplish so, disaggregation results conditioned at the spectral acceleration of the target site at the fundamental period of 0.40s was considered in terms of mean values of magnitude, distance and epsilon, which for the target site were evaluated as 6, 14.5 and 1.5 respectively.…”

“…Nonlinear dynamic analyses were run using properly selected seismic records [12] as input, compatible with the seismic hazard of the target site for 2% probability of exceedance in 50 years. The response of the bridge class was then assessed in terms of repair cost, time quantities such as Crew Working Days (CWD), and the ratio between the cost of repair and the cost of the new construction as function of PGA.…”

Record-to-Record Variability in the Seismic Response of Rc Walls Buildings Subjected to Ground Motions Matched to the Conditional Spectrum

“…A set of 40 ground motions (Set 1), selected to match the conditional spectrum [11,12,13] is used in the analyses. For the final case, a second set of 40 ground motions (Set 2), selected assuming different site characteristics, is used.…”