• Title/Summary/Keyword: Seismic design criteria

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2차원 가새골조의 최적내진설계를 위한 MSA 알고리즘 (Modified Simulated Annealing Algorithms for Optimal Seismic Design of Braced Frame Struvtures)

  • 이상관;성창원;박효선
    • 한국강구조학회 논문집
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    • 제12권6호
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    • pp.629-638
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    • 2000
  • 알고리즘의 용이성과 전역적 최적해로의 수렴가능성 등의 이점을 가진 SA알고리즘은 구조최적화문제에 활발하게 적용되고 있으나 냉각스케줄의 설정, 모호한 종료기준, 과도한 반복해석 등의 문제점을 가지고 있다. 그러므로 본 논문에서는 기존 SA알고리즘의 단점을 보완한 MSA 알고리즘을 개발하고자한다. MSA 알고리즘은 수렴에 요구되는 반복수를 감소시키고 국부최소점이 많은 동적최적화문제의 초기설계 선택의 자율성을 확보하기 위하여 SQ 및 SA의 2단계로 구성하여 개발하였다. 또한 기존 연구에서 제안된 냉각 스케줄에 의한 수렴성 등을 비교분석하여 구조최적화에 적합한 냉각스케줄을 제안하여 그 성능을 평면가새골조 구조물의 최적내진설계에 적용하여 분석하였다.

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Seismic induced damageability evaluation of steel buildings: a Fuzzy-TOPSIS method

  • Shahriar, Anjuman;Modirzadeh, Mehdi;Sadiq, Rehan;Tesfamariam, Solomon
    • Earthquakes and Structures
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    • 제3권5호
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    • pp.695-717
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    • 2012
  • Seismic resiliency of new buildings has improved over the years due to better seismic codes and design practices. However, there is still large number of vulnerable and seismically deficient buildings. It is not economically feasible to retrofit and upgrade all vulnerable buildings, thus there is a need for rapid screening tool. Many factors contribute to the damageability of buildings; this makes seismic evaluation a complex multi-criteria decision making problem. Many of these factors are noncommensurable and involve subjectivity in evaluation that highlights the use of fuzzy-based method. In this paper, a risk-based framework earlier proposed by Tesfamariam and Saatcioglu (2008a) is extended using Fuzzy-TOPSIS method and applied to develop an evaluation and ranking scheme for steel buildings. The ranking is based on damageability that can help decision makers interpret the results and take appropriate decision actions. Finally, the application of conceptual model is demonstrated through a case study of 1994 Northridge earthquake data on seismic damage of steel buildings.

지진파에 의한 매설관로의 좌굴 (Buckling of Buriend Pipelines due to Seismic Waves)

  • 이종세
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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    • pp.109-118
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    • 1999
  • Lifeline system such as oil or gas pipelines and water supply facilities are vulneratble to seismic damages because they are widely exposed to ground failures. Most seismic design criteria of buried pipelines are based on the notion that the longitudinal compressive strain and therefore buckling controls the design. Buckling analysis of buried pipelines subjected to seismic loading is performed by considering the seismic load as the sinusoidally distributed compressive load on the beam on elastic foundation in contrast to existing studies where the buckling load is treated as an end load on the beam column, An approximated analytical solution is obtained by the energy method and its validity is confirmed by the linearized finite element buckling analysis. The results show the beam mode buckling because longitudinal strains at the buckling loads are substantially lower than the strain at the onset of local buckling.

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변전설비 간 상호작용을 고려한 지진응답해석 (Seismic Analysis of Substation Facilities Considering Interaction Effect)

  • 장정범;황경민;서용표;이근직
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2006년도 학술발표회 논문집
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    • pp.605-612
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    • 2006
  • 765kV substation facilities are most important as electric power supply network in the 21 century. So, in order to prevent interruption of electric power supply under earthquake, 765kV substation facilities have to secure the safety against the earthquake. However, even though each substation facility is interconnected mutually, seismic interaction effect doesn't be considered in the initial design. Therefore, seismic capacity evaluation of 765kV substation facilities is carried out considering the seismic interaction effect on a basis of seismic design criteria for Korean transmission and substation facilities.

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한국형 중진지역의 인공지진파 생성을 통한 학교건물 내진안전성 평가 (Evaluation of Seismic Safety in School Buildings Applying Artificial Seismic Waves in Earthquake Magnitude of Korea)

  • 김승현;박영빈;강준석
    • 한국구조물진단유지관리공학회 논문집
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    • 제26권1호
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    • pp.10-18
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    • 2022
  • 국내 발생 지진파형을 분석하여 중진지역 특성을 고려하고 내진설계기준에 부합하는 한국형 인공지진파를 생성하였으며, 획일적이고 미관을 손상시키는 일본식 내진보강 공법을 지양하고 한국형 중진지역의 특징을 반영하여 지진의 빈도가 적고 강도가 비교적 강하지 않은 국내 실정에 적합한 학교 건물의 내진보강 공법을 개발하였다. 이를 바탕으로 현재 과다 설계되어 있는 학교 내진보강 시설물을 중진지역 특성에 맞게 최적화하여 내진 안전성 평가를 수행하였으며, 기존 학교건물의 내진성능평가에 비해 미적인 요소를 고려하고 효율성 있는 구조기법을 적용한 합리적 보강 기법을 제안하였다.

Seismic Performance of High-rise Concrete Buildings in Chile

  • Lagos, Rene;Kupfer, Marianne;Lindenberg, Jorge;Bonelli, Patricio;Saragoni, Rodolfo;Guendelman, Tomas;Massone, Leonardo;Boroschek, Ruben;Yanez, Fernando
    • 국제초고층학회논문집
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    • 제1권3호
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    • pp.181-194
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    • 2012
  • Chile is characterized by the largest seismicity in the world which produces strong earthquakes every $83{\pm}9years$ in the Central part of Chile, where it is located Santiago, the capital of Chile. The short interval between large earthquakes magnitude 8.5 has conditioned the Chilean seismic design practice to achieve almost operational performance level, despite the fact that the Chilean Code declares a scope of life safe performance level. Several Indexes have been widely used throughout the years in Chile to evaluate the structural characteristics of concrete buildings, with the intent to find a correlation between general structural conception and successful seismic performance. The Indexes presented are related only to global response of buildings under earthquake loads and not to the behavior or design of individual elements. A correlation between displacement demand and seismic structural damage is presented, using the index $H_o/T$ and the concrete compressive strain ${\varepsilon}_c$. Also the Chilean seismic design codes pre and post 2010 Maule earthquake are reviewed and the practice in seismic design vs Performance Based Design is presented. Performance Based Design procedures are not included in the Chilean seismic design code for buildings, nevertheless the earthquake experience has shown that the response of the Chilean buildings has been close to operational. This can be attributed to the fact that the drift of most engineered buildings designed in accordance with the Chilean practice falls below 0.5%. It is also known by experience that for frequent and even occasional earthquakes, buildings responded elastically and thus with "fully operational" performance. Taking the above into account, it can be said that, although the "basic objective" of the Chilean code is similar to the SEAOC VISION2000 criteria, the actual performance for normal buildings is closer to the "Essential/Hazardous objective".

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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    • 제84권1호
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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.

변위 비교를 통한 케이블지지교량의 긴급 지진 안전성 평가 방법의 고찰 (Study on the Emergency Assessment about Seismic Safety of Cable-supported Bridges using the Comparison of Displacement due to Earthquake with Disaster Management Criteria)

  • 박성우;이승한
    • 한국구조물진단유지관리공학회 논문집
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    • 제22권6호
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    • pp.114-122
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    • 2018
  • 이 연구에서는 사장교 및 현수교에 부착된 지진가속도계측기를 활용하여 교량의 안전성을 긴급하게 평가할 수 있는 기법을 제안한다. 실측된 지진가속도계측기의 상시 응답을 이용하여 구조해석 모델의 고유주파수와 비교를 통해 최대한 유사한 동적특성을 갖도록 모델링을 개선한다. 설계지진에 대한 지진해석을 수행하여 지진가속도계측기 설치 위치별 최대 변위를 도출하며, 도출된 변위는 사전에 관리기준치로서 시스템에 기 입력된다. 지진발생 시 실시간으로 측정된 가속도 시간이력을 필터링 후 2중적분을 통해 변위시간이력으로 변환한 뒤 최대 변위를 추출한다. 최종적으로 시스템에 기 입력된 관리기준치와 추출된 변위와의 비교를 통해 안전성을 평가한다. 경주지진 시 기록된 데이터를 활용한 12개 특수교량의 긴급 안전성평가 수행을 통해 제안된 방법의 적용성을 확인한다.

중공원형 철근콘크리트 교각의 횡방향철근에 따른 내진성능평가 (Seismic Performance Assessment of Hollow Circular Reinforced Concrete Bridge Columns with Confinement Steel)

  • 김태훈;강형택
    • 한국지진공학회논문집
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    • 제16권1호
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    • pp.13-25
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    • 2012
  • 이 연구의 목적은 중공원형 철근콘크리트 교각의 횡방향철근에 따른 지진거동을 파악하고 합리적이면서 경제적인 내진 설계기준의 개발을 위한 자료를 제공하는데 있다. 3개의 중공원형 교각 실험체에 일정 축하중 하에서 횡방향 반복하중을 가하는 준정적 실험을 수행하였다. 정확하고 올바른 성능평가를 위하여 신뢰성 있는 비선형 유한요소해석 프로그램을 사용하였다. 이용된 해석기법은 조사된 실험체에 대하여 하중단계에 따라 내진성능을 비교적 정확하게 예측하였다. 실험적, 해석적 결과로부터 중공원형 철근콘크리트 교각의 설계와 시공 실무를 향상하기 위한 내진상세를 제시하였다.