• Title/Summary/Keyword: earthquake hazard

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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
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    • v.84 no.1
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    • pp.85-100
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    • 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.

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

  • Lee, Jin-sun;Noh, Gyeong-do
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.6
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    • pp.401-412
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    • 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.

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

  • Yoon, Myung-Ho
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.45-48
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    • 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).

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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.

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

  • Choi, In-Kil;Nakajima, Masato;Choun, Young-Sun;Yun, Kwan-Hee
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.6 s.40
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    • pp.23-29
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    • 2004
  • The design earthquake used for the seismic analysis and design of NPP (Nuclear Power Plant) is determined by the deterministic or probabilistic methods. The probabilistic seismic hazard analysis(PSHA) for the nuclear power plant sites was performed for the probabilistic seismic risk assessment. The probabilistic seismic hazard analysis for the nuclear power plant site had been completed as a part of the probabilistic seismic risk assessment. The probabilistic method become a resonable method to determine the design earthquakes for NPPs. In this study, the defining method of the probability based scenario earthquake was established, and as a sample calculation, the probability based scenario earthquakes were estimated by the de-aggregation of the probabilistic seismic hazard. By using this method, it is possible to define the probability based scenario earthquakes for the seismic design and seismic safety evaluation of structures. It is necessary to develop the rational seismic source map and the attenuation equations for the development of reasonable scenario earthquakes.

Sensitivity Analysis of Seismic Source Models for Probabilistic Seismic Hazard Analysis (확률론적 지진재해도 분석을 위한 지진원 모델의 민감도 분석)

  • 김연중;전정윤;김태균
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.36-45
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    • 2003
  • Sensitivity analyses for several seismic source models were studied. For the area sources, the hazard is steeply decreasing with the source-to-site distance. Hazard is decreasing when the area of the source is increasing with fixed annual rate. For the fault sources, the fault length, distance from a site and dip angle of near fault show very sensitive effect to seismic hazard. But the various magnitude-rupture length relationships show effect to seismic hazard slightly. For the fault source with small magnitude, the exponential model is preferred rather than the characteristic model to the magnitude-recurrence law.

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