• 제목/요약/키워드: Earthquake hazard

검색결과 396건 처리시간 0.022초

The effect of different earthquake ground motion levels on the performance of steel structures in settlements with different seismic hazards

  • Isik, Ercan;Karasin, ibrahim Baran;Karasin, Abdulhalim
    • Structural Engineering and Mechanics
    • /
    • 제84권1호
    • /
    • pp.85-100
    • /
    • 2022
  • The updated Turkish Building Earthquake Code has been significantly renovated and expanded compared to previous seismic design codes. The use of earthquake ground motion levels with different probabilities of exceedance is one of the major advances in structural mechanics with the current code. This study aims to investigate the earthquake performance of steel structure in settlements with different seismic hazards for various earthquake ground motion levels. It is focused on earthquake and structural parameters for four different ground motion levels with different probabilities of exceedance calculated according to the location of the structure by the updated Turkish Hazard Map. For this purpose, each of the seven different geographical regions of Turkey which has the same seismic zone in the previous earthquake hazard map has been considered. Earthquake parameters, horizontal design elastic spectra obtained and comparisons were made for all different ground motion levels for the seven different locations, respectively. Structural analyzes for a sample steel structure were carried out using pushover analysis by using the obtained design spectra. It has been determined that the different ground motion levels significantly affect the expected target displacements of the structure for performance criteria. It is noted that the different locations of the same earthquake zone in the previous code with the same earthquake-building parameters show significant variations due to the micro zoning properties of the updated seismic design code. In addition, the main innovations of the updated code were discussed.

지진 재해도의 닫힌 근사식 제안에 관한 연구 (A Study to Propose Closed-form Approximations of Seismic Hazard)

  • 곽신영;함대기
    • 한국지진공학회논문집
    • /
    • 제22권4호
    • /
    • pp.245-251
    • /
    • 2018
  • In this paper, we address some issues in existing seismic hazard closed-form equations and present a novel seismic hazard equation form to overcome these issues. The presented equation form is based on higher-order polynomials, which can well describe the seismic hazard information with relatively high non-linearity. The accuracy of the proposed form is illustrated not only in the seismic hazard data itself but also in estimating the annual probability of failure (APF) of the structural systems. For this purpose, the information on seismic hazard is used in representative areas of the United States (West : Los Angeles, Central : Memphis and Kansas, East : Charleston). Examples regarding the APF estimation are the analyses of existing platform structure and nuclear power plant problems. As a result of the numerical example analyses, it is confirmed that the higher-order-polynomial-based hazard form presented in this paper could predict the APF values of the two example structure systems as well as the given seismic hazard data relatively accurately compared with the existing closed-form hazard equations. Therefore, in the future, it is expected that we can derive a new improved APF function by combining the proposed hazard formula with the existing fragility equation.

비선형 유효응력해석을 이용한 1995 Kobe 지진시 케이슨 안벽의 거동 평가 (Evaluation of Caisson Quay Wall Behavior during the 1995 Kobe Earthquake by Nonlinear Effective Stress Analysis)

  • 이진선;노경도
    • 한국지진공학회논문집
    • /
    • 제20권6호
    • /
    • pp.401-412
    • /
    • 2016
  • On Tuesday, January 17, 1995, an earthquake of magnitude 7.2 struck the Port of Kobe. In effect, the port was practically destroyed. After a hazard investigation, researchers reached a consensus to adopt a performance-based design in port and harbor structures in Japan. A residual displacement of geotechnical structures after an earthquake is one of the most important engineering demands in performance-based earthquake-resistant design. Thus, it is essential to provide reliable responses of geotechnical structures after an earthquake through various techniques. Today, a nonlinear explicit response history analysis(NERHA) of geotechnical structures is the most efficient way to achieve this goal. However, verification of the effective stress analysis, including post liquefaction behavior, is difficult to perform at a laboratory scale. This study aims to rigorously verify the NERHA by using well-defined field measurements, existing numerical tools, and constitutive models. The man-made, Port Island, in Kobe provides intensive hazard investigation data, strong motion records of 1995 Kobe earthquake, and sufficient engineering parameters of the soil. Two dimensional numerical analysis was conducted on the caisson quay wall section at Port Island subjected to the 1995 Kobe earthquake. The analysis result matches very well with the hazard investigation data. The NERHA procedure presented in this paper can be used in further studies to explain and examine the effects of other factors on the seismic behavior of gravity quay walls in liquefiable soil areas.

평창지진의 에너지 응답 특성에 관한 연구 (A Study on the Response Energy Characteristics of Pyungchang Earthquake)

  • 윤명호
    • 한국방재학회:학술대회논문집
    • /
    • 한국방재학회 2008년도 정기총회 및 학술발표대회
    • /
    • pp.45-48
    • /
    • 2008
  • The Pyungchang earthquake(Jan. 2007, Ml4.9) have recorded PGA of about 0.15g at the Daegwanryung observation station nearby from the epicenter. In this paper the energy response spectrum analyses for the Pyungchang earthquake were carried out and compared with well known American earthquake Taft(1952).

  • PDF

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
    • /
    • 제9권4호
    • /
    • pp.719-733
    • /
    • 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.

확률론적 지진재해도를 이용한 시나리오 지진의 결정기법에 관한 연구 (Study on the Scenario Earthquake Determining Methods Based on the Probabilistic Seismic Hazard Analysis)

  • 최인길;중도정인;전영선;연관희
    • 한국지진공학회논문집
    • /
    • 제8권6호통권40호
    • /
    • pp.23-29
    • /
    • 2004
  • 원전 구조물 및 기기의 내진설계를 위한 설계지진의 설정에는 결정론적 방법이나 확률론적 방법이 사용되어 왔다. 최근에는 확률론적 지진재해도 분석이 일반화 되면서 확률론적으로 설계지진 및 평가용 지진의 설정 방법이 합리적인 방법으로서 인식되어 많이 사용되고 있다. 우리나라의 경우 원전부지에 대한 확률론적 지진재해도 분석이 확률론적 지진위험도 평가의 일환으로 대부분 완료되어 있다. 본 연구에서는 확률론적 지진재해도의 재분해를 통하여 확률론적 시나리오 지진을 산정할 수 있는 기법을 확립하고 국내 원전 부지에 대한 확률론적 지진재해도 분석 결과를 이용하여 계산 예를 수행하였다. 이 기법을 사용하면 내진설계 및 내진안전성 평가에 활용할 수 있는 확률론적 시나리오 지진을 설정할 수 있어 매우 유용한 것으로 판단되며 합리적인 시나리오 지진의 산정을 위해서는 합리적인 지진구역도 및 감쇄식의 개발이 필요하다.