• Title/Summary/Keyword: seismic methods

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Study on seismic behavior and seismic design methods in transverse direction of shield tunnels

  • He, Chuan;Koizumi, Atsushi
    • Structural Engineering and Mechanics
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    • v.11 no.6
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    • pp.651-662
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    • 2001
  • In order to investigate the seismic behavior and seismic design methods in the transverse direction of a shield tunnel, a series of model shaking table tests and a two-dimensional finite element dynamic analysis on the tests are carried out. Two kinds of static analytical methods based on ground-tunnel composite finite element model and beam-spring element model are proposed, and the validity of the static analyses is verified by model shaking table tests. The investigation concerns the dynamic response behavior of a tunnel and the ground, the interaction between the tunnel and ground, and an evaluation of different seismic design methods. Results of the investigation indicate that the shield tunnel follows the surrounding ground in displacement and dynamic characteristics in the transverse direction; also, the static analytical methods proposed by the authors can be used directly as the seismic design methods in the transverse direction of a shield tunnel.

Performance-based seismic evaluation and practical retrofit techniques for buildings in China

  • Wang, Hao;Sun, Baitao;Chen, Hongfu
    • Earthquakes and Structures
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    • v.22 no.5
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    • pp.487-502
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    • 2022
  • China is prone to earthquake disasters, and the higher seismic performance is required by many existing civil buildings. And seismic evaluation and retrofit are effective measures to mitigate seismic hazards. With the development of performance-based seismic design and diverse retrofit technology for buildings, advanced evaluation methods and retrofit strategies are in need. In this paper, we introduced the evolution of seismic performance objectives in China combined with performance-based seismic design. Accordingly, multi-phase evaluation methods and comprehensive seismic capacity assessment are introduced. For buildings with seismic deficiency or higher performance requirements, the retrofit technologies are categorized into three types: component strengthening, system optimization, and passive control. Both engineering property and social property for the retrofit methods are discussed. The traditional seismic retrofit methods usually are costly and disturbing, and for example in Beijing, seismic strengthening costs approx. 1000 RMB/m2 (for 160 USD/m2), for hospital building even more expensive as 5000 RMB/m2(for 790 USD/m2). So cost-efficient and little disturbance methods are promising techniques. In the end, some opinions about the retrofit strategy and schemes category are shared and wish to discuss the situation and future of seismic retrofit in China.

Compare Seismic Coefficient Method and Seismic Response Analysis for Slope during Earthquake (지진시 사면안정해석에 있어서의 진도법과 지진응답해석의 결과 비교)

  • 박성진;오병현;박춘식;황성춘
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.193-200
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    • 2000
  • Numerical analysis of slope stability is presented using slice method, static seismic analysis methods, and earthquake response analysis methods. Static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis, Hachinohe-wave is applied. Safety factor calculated using slice method for failure surface. Calculating methods are Bishop's method and Janhu's method. Static seismic analysis was applied using Mhor-Coulomb model and earthquake response analysis was applied using non-linear elastic model.

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Method for soil-structure dynamic interaction analysis(I) (지반-구조물의 동적 상호작용 해석법(I))

  • 황성춘
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.144-151
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    • 2001
  • The development history of seismic design and analysis methods considering seismic force in soil-structure dynamic interaction are presented. Determination of seismic intensity in static analysis of both seismic and modifided seismic methods is discussed and preferable method in future seismic design is proposed.

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Numerical Analysis for Buried Box Structures during Earthquake (지중 박스구조물의 지진시 거동 해석)

  • 박성진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.108-115
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    • 2000
  • Numerical analysis of slop stability is presented using seismic displacement, response seismic coefficient, and earthquake response analysis methods. In seismic displacement and response seismic coefficient methods, horizontal static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis Hahinoha-wave is applied, It is found from result that analysis using response seismic coefficient method is much more conservative than that using seismic displacement method Also, analysis result using earthquake response analysis method is somewhat less conservative about 25% when compared with that using seismic displacement method.

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Seismic response estimation of steel plate shear walls using nonlinear static methods

  • Dhar, Moon Moon;Bhowmick, Anjan K.
    • Steel and Composite Structures
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    • v.20 no.4
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    • pp.777-799
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    • 2016
  • One of the major components for performance based seismic design is accurate estimation of critical seismic demand parameters. While nonlinear seismic analysis is the most appropriate analysis method for estimation of seismic demand parameters, this method is very time consuming and complex. Single mode pushover analysis method, N2 method and multi-mode pushover analysis method, modal pushover analysis (MPA) are two nonlinear static methods that have recently been used for seismic performance evaluation of few lateral load-resisting systems. This paper further investigates the applicability of N2 and MPA methods for estimating the seismic demands of ductile unstiffened steel plate shear walls (SPSWs). Three different unstiffened SPSWs (4-, 8-, and 15-storey) designed according to capacity design approach were analysed under artificial and real ground motions for Vancouver. A comparison of seismic response quantities such as, height-wise distribution of floor displacements, storey drifts estimated using N2 and MPA methods with more accurate nonlinear seismic analysis indicates that both N2 and MPA procedures can reasonably estimates the peak top displacements for low-rise SPSW buildings. In addition, MPA procedure provides better predictions of inter-storey drifts for taller SPSW. The MPA procedure has been extended to provide better estimate of base shear of SPSW.

Development and Practice of Performance-Based Seismic Design of High-Rise Buildings in China

  • Xiao Congzhen;Li Jianhui;Li Yinbin;Qiao Baojuan;Sun Chao;Wei Yue;Ding Jiannan
    • International Journal of High-Rise Buildings
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    • v.12 no.3
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    • pp.209-214
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    • 2023
  • Seismic performance-based design methods are widely used in the field of engineering. This paper introduces the current status of seismic performance-based design methods for high-rise buildings in China, and summarizes latest advancements in seismic performance-based design methods for high-rise buildings in China, with a focus on the design methods based on predetermined yield mode and the design methods based on member ductility requirements. Finally, the development direction of seismic performance-based design method for high-rise buildings is prospected.

Earthquake risk assessment methods of unreinforced masonry structures: Hazard and vulnerability

  • Preciado, Adolfo;Ramirez-Gaytan, Alejandro;Salido-Ruiz, Ricardo A.;Caro-Becerra, Juan L.;Lujan-Godinez, Ramiro
    • Earthquakes and Structures
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    • v.9 no.4
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    • pp.719-733
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    • 2015
  • Seismic risk management of the built environment is integrated by two main stages, the assessment and the remedial measures to attain its reduction, representing both stages a complex task. The seismic risk of a certain structure located in a seismic zone is determined by the conjunct of the seismic hazard and its structural vulnerability. The hazard level mainly depends on the proximity of the site to a seismic source. On the other hand, the ground shaking depends on the seismic source, geology and topography of the site, but definitely on the inherent earthquake characteristics. Seismic hazard characterization of a site under study is suggested to be estimated by a combination of studies with the history of earthquakes. In this Paper, the most important methods of seismic vulnerability evaluation of buildings and their application are described. The selection of the most suitable method depends on different factors such as number of buildings, importance, available data and aim of the study. These approaches are classified in empirical, analytical, experimental and hybrid. For obtaining more reliable results, it is recommends applying a hybrid approach, which consists of a combination between methods depending on the case. Finally, a recommended approach depending on the building importance and aim of the study is described.

A Basic Study on Comparison Analysis of Seismic Reinforcement Method Guideline between Domestic and Foreign Educational Facilities (국내외 교육시설물 내진보강공법 가이드라인 비교분석 기초연구)

  • Lee, Joo-Hyeong;Jeon, Sang-Sub;Son, Ki-Young;Son, Seung-Hyun;Na, Young-Ju
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.85-86
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    • 2019
  • Recently, the educational facilities were 45% among total damaged facilities from the Po-Hang earthquake. Consequently, the seismic reinforcement of existing educational facilities were ended up attracting people's interesting. However, research is insufficient to consider that how far technology has been developed. Therefore, the purpose of this study is to investigate the level of domestic guideline research by comparing to foreign guidelines in regard to seismic reinforcement methods applicable to existing educational facilities. To achieve the objective, first, the current status of seismic reinforcement projects in domestic educational facilities was analyzed. Second, the domestic and foreign seismic reinforcement methods guidelines for structural, non-structural was compared. Third, the improvement directions for future guidelines were suggested. As a results, the improvement directions of domestic seismic reinforcement methods guidelines were proposed. First, the structural seismic reinforcement strategy needs to be segmented. Second, it is necessary to analyze about non-structural guidelines based on additional cases. In the future, this study can be used as a basic material for developing seismic reinforcement methods guidelines in domestic existing educational facilities.

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Comparison of Seismic Responses of Underground Utility Tunnels Using Simplified Analysis Methods (단순화 해석 방법에 따른 지하공동구 지진 응답 산정 비교)

  • Kim, Dae-Hwan;Lim, Youngwoo;Seo, Hyun-Jeong;Lee, Hyerin
    • Journal of the Earthquake Engineering Society of Korea
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    • v.28 no.4
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    • pp.205-213
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    • 2024
  • In the seismic evaluation of underground utility tunnels, selecting an analytical method is critical to estimating reasonable seismic responses. In simplified pseudo-static analysis methods widely applied to typical seismic design and evaluation of underground tunnels in practice, it is essential to check whether the methods provide valid results for cut-and-cover tunnels buried in shallow to medium depth. The differences between the two simplified pseudo-static methods are discussed in this study, and the analysis results are compared to those obtained from FLAC models. In addition to the analysis methods, seismic site classification, overburden soil depth, and sectional configuration are considered variables to examine their effects on the seismic response of underground utility tunnels. Based on the analysis results, the characteristics derived from the concepts and details of each simplified model are discussed. Also, general observations are made for the application of simplified analysis methods.