Decomposing seismic accelerograms with optimized window and its application for generating artificial fully non-Gaussian and nonstationary ground motion time histories

2022 ◽  
Vol 154 ◽  
pp. 107124
Author(s):  
X.Z. Cui ◽  
H.P. Hong
2017 ◽  
Author(s):  
Duruo Huang ◽  
Wenqi Du

Abstract. In performance-based seismic design, ground-motion time histories are needed for analyzing dynamic responses of nonlinear structural systems. However, the number of strong-motion data at design level is often limited. In order to analyze seismic performance of structures, ground-motion time histories need to be either selected from recorded strong-motion database, or numerically simulated using stochastic approaches. In this paper, a detailed procedure to select proper acceleration time histories from the Next Generation Attenuation (NGA) database for several cities in Taiwan is presented. Target response spectra are initially determined based on a local ground motion prediction equation under representative deterministic seismic hazard analyses. Then several suites of ground motions are selected for these cities using the Design Ground Motion Library (DGML), a recently proposed interactive ground-motion selection tool. The selected time histories are representatives of the regional seismic hazard, and should be beneficial to earthquake studies when comprehensive seismic hazard assessments and site investigations are yet available. Note that this method is also applicable to site-specific motion selections with the target spectra near the ground surface considering the site effect.


1999 ◽  
Vol 89 (2) ◽  
pp. 501-520 ◽  
Author(s):  
Paolo Bazzurro ◽  
C. Allin Cornell

Abstract Probabilistic seismic hazard analysis (PSHA) integrates over all potential earthquake occurrences and ground motions to estimate the mean frequency of exceedance of any given spectral acceleration at the site. For improved communication and insights, it is becoming common practice to display the relative contributions to that hazard from the range of values of magnitude, M, distance, R, and epsilon, ɛ, the number of standard deviations from the median ground motion as predicted by an attenuation equation. The proposed disaggregation procedures, while conceptually similar, differ in several important points that are often not reported by the researchers and not appreciated by the users. We discuss here such issues, for example, definition of the probability distribution to be disaggregated, different disaggregation techniques, disaggregation of R versus ln R, and the effects of different binning strategies on the results. Misconception of these details may lead to unintended interpretations of the relative contributions to hazard. Finally, we propose to improve the disaggregation process by displaying hazard contributions in terms of not R, but latitude, longitude, as well as M and ɛ. This permits a display directly on a typical map of the faults of the surrounding area and hence enables one to identify hazard-dominating scenario events and to associate them with one or more specific faults, rather than a given distance. This information makes it possible to account for other seismic source characteristics, such as rupture mechanism and near-source effects, during selection of scenario-based ground-motion time histories for structural analysis.


1998 ◽  
Vol 25 (2) ◽  
pp. 305-318 ◽  
Author(s):  
Gail M Atkinson ◽  
Igor A Beresnev

Ground-motion time histories which are compatible with the uniform hazard spectra (UHS) provided by the new national seismic hazard maps of the Geological Survey of Canada (GSC) are simulated. Time histories are simulated for the following cities: Halifax, La Malbaie, Québec, Montreal, Ottawa, Toronto, Prince George, Tofino, Vancouver, and Victoria. The target UHS for the time history simulations are the GSC 5% damped horizontal-component spectra for "firm ground" (Class B) sites for an annual probability of 1/500. The Canadian Council on Earthquake Engineering is currently considering the adoption of these maps as the seismological basis for the earthquake design requirements for future editions of the National Building Code of Canada. It is therefore useful to have compatible time histories for these spectra, in order that dynamic analysis methods requiring the use of time histories can be employed. The simulated records provide a realistic representation of ground motion for the earthquake magnitudes and distances that contribute most strongly to hazard at the selected cities and probability level. For each selected city, two horizontal components are generated for a moderate earthquake nearby, and two horizontal components are generated for a larger earthquake farther away. These records match the short- and long-period ends of the target UHS, respectively. These simulations for local and regional crustal earthquakes are based on a point-source stochastic simulation procedure. For cities in British Columbia, records are also simulated for a scenario M8.5 earthquake on the Cascadia subduction zone, using a stochastic finite-fault simulation model. Four different rupture scenarios are considered. The ground motions for this scenario event are not associated with a specific probability level, but current information suggests that their probability of occurrence is comparable to that of the 1/500 UHS (the probabilistic analyses performed for the national hazard maps do not explicitly include the Cascadia subduction event). Thus it would be reasonable to conduct engineering analyses for cities in British Columbia using both the simulated crustal-event motions and the simulated Cascadia-event motions for the Cascadia event. The time histories simulated for this study are available free of charge to all interested parties.Key words: compatible time-histories, seismic hazard, ground motions.


2014 ◽  
Vol 104 (4) ◽  
pp. 1914-1929 ◽  
Author(s):  
R. Kamai ◽  
N. Abrahamson ◽  
R. Graves

2017 ◽  
Vol 11 (03) ◽  
pp. 1750006
Author(s):  
Ajin Baby ◽  
Manish Shrikhande

With increased emphasis on performance-based seismic design, the need for appropriate ground motion time histories for use in nonlinear dynamic analyses is felt accutely. However, it is generally not possible to get a suitable recorded time history consistent with the estimated hazard at a specific site. The ground motion prediction models are therefore derived/developed from a statistical analysis of recorded ground motion for a variety of source and site conditions to address this need. Most often, the ground motion prediction models are developed to model the response spectrum amplitudes at a set of natural periods and the ground motion time history, if required, is then generated to be consistent with this predicted response spectrum. These simulated time histories often lack in modeling the wave arrivals and temporal variation in the distribution of energy with respect to frequency. In this paper, we present a wavelet-based ground motion prediction model for directly generating ground motion time history that is consistent with the postulated scenario earthquake at a site.


Author(s):  
Vaneeta Devi ◽  
M. L. Sharma

Time-frequency representation and spectral features extraction from a digitally recorded ground motion time history of an earthquake is cornerstone in earthquake engineering signal processing and interpretation. Recently developed time-frequency analysis (TFA) techniques are one of the most suitable techniques for the spectral estimation of signals whose frequency content varies with time. The most often used TFA techniques are short-term Fourier transform, Gabor transform, wavelet transform, Wigner-Ville distribution, Choi-William distribution, and cone shape distribution. The spectrograms of TFA reveal better spectral estimation in time-frequency domain and hence recommended to estimate local frequencies, dominate frequency and their incident time. Moreover, the time of occurrence of frequency component corresponding to maximum energy burst as well as its variation with time can also be identified. Results obtained from TFA techniques shows better picture of the spectral content in the data than the other conventional techniques.


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