Spectral acceleration

About: Spectral acceleration is a research topic. Over the lifetime, 1223 publications have been published within this topic receiving 39329 citations.

Prediction of horizontal response spectra in europe

Abstract: A large and uniform dataset is used to find equations for the prediction of absolute spectral acceleration ordinates in Europe and adjacent areas, in terms of magnitude, source-distance and site geology. The dataset used is shown to be representative of European strong motion in terms of the attenuation of peak ground acceleration. The equations are recommended for use in the range of magnitudes from M s 4.0 to 7.5 and for source-distances of up to 200 km.

Spectral shape, epsilon and record selection

Abstract: SUMMARY Selection of earthquake ground motions is considered with the goal of accurately estimating the response of a structure at a specied ground motion intensity, as measured by spectral acceleration at therst- mode period of the structure, Sa(T1). Consideration is given to the magnitude, distance and epsilon (� ) values of ground motions. First, it is seen that selecting records based on theirvalues is more eective than selecting records based on magnitude and distance. Second, a method is discussed fornding the conditional response spectrum of a ground motion, given a level of Sa(T1) and its associated mean (disaggregation-based) causal magnitude, distance andvalue. Records can then be selected to match the mean of this target spectrum, and the same benets are achieved as when records are selected based on � . This mean target spectrum diers from a Uniform Hazard Spectrum, and it is argued that this new spectrum is a more appropriate target for record selection. When properly selecting records based on either spectral shape or � , the reductions in bias and variance of resulting structural response estimates are comparable to the reductions achieved by using a vector-valued measure of earthquake intensity. Copyright ? 2006 John Wiley & Sons, Ltd.

NGA Project Strong-Motion Database

Abstract: A key component of the NGA research project was the development of a strong-motion database with improved quality and content that could be used for ground-motion research as well as for engineering practice. Development of the NGA database was executed through the Lifelines program of the PEER Center with contributions from several research organizations and many individuals in the engineering and seismological communities. Currently, the data set consists of 3551 publicly available multi-component records from 173 shallow crustal earthquakes, ranging in magnitude from 4.2 to 7.9. Each acceleration time series has been corrected and filtered, and pseudo absolute spectral acceleration at multiple damping levels has been computed for each of the 3 components of the acceleration time series. The lowest limit of usable spectral frequency was determined based on the type of filter and the filter corner frequency. For NGA model development, the two horizontal acceleration components were further rotated to form the orientationindependent measure of horizontal ground motion (GMRotI50). In addition to the ground-motion parameters, a large and comprehensive list of metadata characterizing the recording conditions of each record was also developed. NGA data have been systematically checked and reviewed by experts and NGA developers. DOI: 10.1193/1.2894831

Attenuation Relations of Strong Ground Motion in Japan Using Site Classification Based on Predominant Period

Abstract: A spectral acceleration attenuation model for Japan is presented in the present study. The data set includes a very large number of strong ground-motion records up to the 2003 Off Tokach main and aftershocks. Site class terms, instead of individual site correction terms, are used. The site classes of recording stations are from a recent study on site classification for strong-motion recording stations in Japan according to a classification scheme that has been used in Japanese engineering design. The use of site class terms enables tectonic source-type effects to be identified and accounted for in the present model. The effects of a faulting mechanism for crustal earthquakes also are accounted for. For crustal and interface earthquakes, a simple form of an attenuation model (with respect to distance) is able to capture the main strong-motion characteristics and achieves unbiased estimates. For subduction slab events, a simple distance modification factor is employed to achieve plausible and unbiased predictions. The effects of source depth, tectonic source type, and faulting mechanism of crustal earthquakes are significant. The need for magnitude- squared terms is evaluated, and the use of magnitude-squared terms reduces the interevent error further.

A vector-valued ground motion intensity measure consisting of spectral acceleration and epsilon

Abstract: The ‘strength’ of an earthquake ground motion is often quantified by an Intensity Measure (IM), such as peak ground acceleration or spectral acceleration at a given period. This IM is used to predict the response of a structure. In this paper an intensity measure consisting of two parameters, spectral acceleration and epsilon, is considered. The IM is termed a vector-valued IM, as opposed to the single parameter, or scalar, IMs that are traditionally used. Epsilon (defined as a measure of the difference between the spectral acceleration of a record and the mean of a ground motion prediction equation at the given period) is found to have significant ability to predict structural response. It is shown that epsilon is an indicator of spectral shape, explaining why it is related to structural response. By incorporating this vector-valued IM with a vector-valued ground motion hazard, we can predict the mean annual frequency of exceeding a given value of maximum interstory drift ratio, or other such response measure. It is shown that neglecting the effect of epsilon when computing this drift hazard curve leads to conservative estimates of the response of the structure. These observations should perhaps affect record selection in the future. Copyright © 2005 John Wiley & Sons, Ltd.