Earthquake Engineering & Structural Dynamics最新文献

{"title":"System‐reliability‐based disaster resilience analysis for structures considering aleatory uncertainties in external loads","authors":"S. Yi, Taeyong Kim","doi":"10.1002/eqe.3991","DOIUrl":"https://doi.org/10.1002/eqe.3991","url":null,"abstract":"The concept of disaster resilience is getting more prominent in the era of climate change due to the increase in the intensities and uncertainties of disaster events. To effectively assess the holistic capacity of structural systems, a disaster resilience analysis framework has been developed from a system‐reliability‐based perspective. The framework evaluates resilience in terms of reliability, redundancy, and recoverability and provides quantitative indices of reliability and redundancy for structures with a resilience threshold. Although this framework enables the comprehensive evaluation of disaster resilience performance, practical applications of such concepts to the structures subjected to dynamic excitations with large aleatory uncertainty, such as earthquakes, remain challenging. This study develops a framework to assess the resilience performance of structures by taking into account the aleatory uncertainties in external forces. Along with the development of reliability and redundancy curves that can effectively accommodate such excitations, a new resilience threshold representation is proposed to incorporate recoverability in the decision‐making process. Moreover, we provide efficient procedures for calculating the reliability and redundancy curves to alleviate the computational complexity during the resilience analysis. Two earthquake application examples are presented targeting a nine‐story building and a cable‐stayed bridge system to demonstrate the enhanced practical applicability of the proposed framework.","PeriodicalId":287805,"journal":{"name":"Earthquake Engineering & Structural Dynamics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120261456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response spectrum method for structures subjected to vertical ground motions: Absolute acceleration method","authors":"Andrés A. Acosta, E. Miranda, G. Deierlein","doi":"10.1002/eqe.3988","DOIUrl":"https://doi.org/10.1002/eqe.3988","url":null,"abstract":"Although a wide variety of response spectrum methods have been developed to estimate peak horizontal building responses, much less attention has been devoted to study the applicability of those methods for the vertical direction or to develop new methods to estimate peak vertical building responses. Vertical building responses can be significant for structures located close to the earthquake rupture, and for buildings with fundamental period of vibration within the range of most energy content of the vertical component of the ground motion (typically 0.05 to 0.15 s). The frequency content of the vertical component is significantly different to that in the horizontal components; thus, it is not clear if previous methods are applicable. We present a new alternative response spectrum analysis (RSA) method to estimate absolute accelerations in the vertical direction, which is a modified version of a previously studied modal combination rule developed for the horizontal components of motion. This formulation is derived based on the use of modal absolute accelerations, and we compare it to the traditional complete quadratic combination (CQC). In the proposed method, we develop simplified equations to estimate the necessary correlation coefficients for the vertical direction which are calibrated to fit empirical correlations computed from the vertical response of single degree of freedom systems subjected to a set of 90 vertical components of recorded ground motions. We also compute these correlations by using an improved power spectral density (PSD) function, which is as an enhanced version of the modified Kanai‐Tajimi PSD to represent the frequency content in the vertical direction which differs from that in the horizontal direction. To evaluate the proposed modal combination rule, we compare the RSA results to those obtained using response history analyses (RHA) of peak responses for a simplified model consisting of a prismatic bar fixed only at one end, as well as for 2D frames. We show that the proposed modal combination rule can estimate peak building responses with higher accuracy than the commonly used CQC modal combination rule, for any general building configuration at any structural location.","PeriodicalId":287805,"journal":{"name":"Earthquake Engineering & Structural Dynamics","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120659186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}