Abstract

This paper focuses on the identification of high-efficiency intensity measures to predict the seismic response of buildings affected by near- and far-fault ground motion records. Near-fault ground motion has received special attention, as it tends to increase the expected damage to civil structures compared to that from ruptures originating further afield. In order to verify this tendency, the nonlinear dynamic response of 3D multi-degree-of-freedom models is estimated by using a subset of records whose distance to the epicenter is lower than 10 km. In addition, to quantify how much the expected demand may increase because of the proximity to the fault, another subset of records, whose distance to the epicenter is in the range between 10 and 30 km, has been analyzed. Then, spectral and energy-based intensity measures as well as those obtained from specific computations of the ground motion record are calculated and correlated to several engineering demand parameters. From these analyses, fragility curves are derived and compared for both subsets of records. It has been observed that the subset of records nearer to the fault tends to produce fragility functions with higher probabilities of exceedance than the ones derived for far-fault records. Results also show that the efficiency of the intensity measures is similar for both subsets of records, but it varies depending on the engineering demand parameter to be predicted.

Highlights

  • It has been observed that a single intensity measures (IMs) is not able to predict, with the highest efficiency, all the engineering demand parameters (EDPs) considered in this research

  • A general efficiency can be estimated by averaging all the R2 associated to each IM-EDP set of points

  • Results presented in this article indicate that the accuracy in seismic risk estimations can be improved if variables related to the velocity, energy, or even displacement at the ground level are used as IMs

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Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. This article is focused on two main aspects The former is to find intensity measures (IMs) exhibiting high efficiency to predict engineering demand parameters (EDPs) when near- and far-fault records are considered. IM-EDP pairs exhibiting high levels of correlation are suitable candidates to analyze the expected damage of buildings subject to ground motions This is because fragility functions obtained through these highly correlated pairs will exhibit less variability when determining the probability of exceeding a certain damage level assumed as a limit state. From each subset of ground motion records, a group of IMs are obtained and correlated with the EDPs. Two main aspects will be analyzed: (i) the efficiency of each IM to predict EDPs and (ii) how much the structural response increases in terms of some EDP due to the proximity to the source of the records. The consequences of this increased demand are analyzed through the derivation of fragility functions

Probabilistic Characterization of the Structural Models
Epistemic Uncertainties in Structural Input Variables
Geometrical Properties
Seismic Hazard
Intensity Measures
Spectral-Based Intensity Measures
Energy-Based Intensity Measures
IMs Based on Direct Computations of the Ground Motion Record
Engineering Demand Parameters
Statistical Analysis of IM-EDP Pairs
Analysis of IMs Efficiency
Near-Fault Ground Motion Records
Far-Fault Ground Motion Records
Spearman Coefficcient
12. Comparison
Fragility Functions
Findings
Concluding Remarks
Full Text
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