• 제목/요약/키워드: Service/Frequent earthquake

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A methodology for design of metallic dampers in retrofit of earthquake-damaged frame

  • Zhang, Chao;Zhou, Yun;Weng, Da G.;Lu, De H.;Wu, Cong X.
    • Structural Engineering and Mechanics
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    • 제56권4호
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    • pp.569-588
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    • 2015
  • A comprehensive methodology is proposed for design of metallic dampers in seismic retrofit of earthquake-damaged frame structures. It is assumed that the metallic dampers remain elastic and only provide stiffness during frequent earthquake (i.e., earthquake with a 63% probability of exceedance in 50-year service period), while in precautionary earthquake (i.e., earthquake with a 10% probability of exceedance in 50-year service period), the metallic dampers yield before the main frame and dissipate most of the seismic energy to either prevent or minimize structural damages. Therefore by converting multi-story frame to an equivalent single-degree-of-freedom system, the added stiffness provided by metallic dampers is designed to control elastic story drifts within code-based demand under frequent earthquake, and the added damping with the combination of added stiffness influences is obtained to control structural stress within performance-based target under precautionary earthquake. With the equivalent added damping ratio, the expected damping forces provided by metallic dampers can be calculated to carry out the configuration and design of metallic dampers along with supporting braces. Based on a detailed example for retrofit of an earthquake-damaged reinforced concrete frame by using metallic dampers, the proposed design procedure is demonstrated to be simple and practical, which can not only meet current China's design codes but also be used in retrofit design of earthquake-damaged frame with metallic damper for reaching desirable performance objective.

Performance Based Seismic Design State of Practice, 2012 Manila, Philippines

  • Sy, Jose A.;Anwar, Naveed;HtutAung, Thaung;Rayamajhi, Deepak
    • 국제초고층학회논문집
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    • 제1권3호
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    • pp.203-209
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    • 2012
  • The purpose of this paper is to present the state of practice being used in the Philippines for the performance-based seismic design of reinforced concrete tall buildings. Initially, the overall methodology follows "An Alternative Procedure for Seismic Analysis and Design of Tall Buildings Located in the Los Angeles Region, 2008", which was developed by Los Angeles Tall Buildings Structural Design Council. After 2010, the design procedure follows "Tall Buildings Initiative, Guidelines for Performance-Based Seismic Design of Tall Buildings, 2010" developed by Pacific Earthquake Engineering Research Center (PEER). After the completion of preliminary design in accordance with code-based design procedures, the performance of the building is checked for serviceable behaviour for frequent earthquakes (50% probability of exceedance in 30 years, i.e,, with 43-year return period) and very low probability of collapse under extremely rare earthquakes (2% of probability of exceedance in 50 years, i.e., 2475-year return period). In the analysis, finite element models with various complexity and refinements are used in different types of analyses using, linear-static, multi-mode pushover, and nonlinear-dynamic analyses, as appropriate. Site-specific seismic input ground motions are used to check the level of performance under the potential hazard, which is likely to be experienced. Sample project conducted using performance-based seismic design procedures is also briefly presented.

The Campus of University Earthquake Disaster Prevention Planning - The Research of Spatial Pattern Based on GIS

  • Mi, Shan;Piao, Yong-Ji;Zhang, Rui;Cho, Tae-Dong
    • 한국환경과학회지
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    • 제23권7호
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    • pp.1213-1221
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    • 2014
  • In the background of rapid urbanization and frequent earthquakes, earthquake disaster prevention planning has become an important topic of current research. Universities are irreplaceable disaster shelter, as they are public institutions with a lot of open space. This article puts forward the concept of "disaster prevention campus". With the refuge behavioral and psychological characteristics of people in the campus when the earthquake happens, it integrated uses GIS spatial analysis technique, takes Shandong Agricultural University as an example, and studies the spatial pattern of earthquake disaster prevention planning in campus from five aspects. The aspects include building distribution, population distribution, analysis of service radius, infrastructure configuration and choice of the optimal refuge path. On the basis of researches above, reform proposals and specific strategies are put forward to build the safe and harmonious disaster prevention campus.

Application of Buckling Restrained Braces in a 50-Storey Building

  • Sy, Jose A.;Anwar, Naveed;Aung, Thaung Htut;Rayamajhi, Deepak
    • 국제초고층학회논문집
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    • 제3권1호
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    • pp.81-87
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    • 2014
  • The use of Buckling Restrained Braces (BRB) for enhancing the performance of the buildings is gaining wider acceptance. This paper presents the first application of these devices in a major high-rise building in the Philippines. A 50-storey residential reinforced concrete building tower, with ductile core wall, with BRB system is investigated. The detailed modeling and design procedure of buckling restrained brace system is presented for the optimal design against the two distinct levels of earthquake ground motions; serviceable behavior for frequent earthquakes and very low probability of collapse under extremely rare earthquakes. The stiffness and strength of the buckling restrained brace system are adjusted to optimize the performance of the structural system under different levels of earthquakes. Response spectrum analysis is conducted for Design Basis Earthquake level and Service level, while nonlinear time history analysis is performed for the most credible earthquake. The case study results show the effectiveness of buckling restrained braces.

면진 장치 적용 전, 후의 철골조의 내진 성능 평가 (Evaluation of Seismic Performance of Steel Frame before and after Application of Seismic Isolator)

  • 김대곤;이상훈;안재현;박칠림
    • 한국지진공학회논문집
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    • 제2권1호
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    • pp.47-62
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    • 1998
  • 내진 설계되지 않은 일경간-이층 철골조의 면진에 사용될 적층 고무베어링과 납-고무 베어링을 설계하여 철골조와 기초 사이에 이 면진장치들을 적용하여 지진파들에 대한 내진 성능 평가를 행하였다. 이들 면진장치들을 사용하면 철골조의 내진성능이 향상된다. 특히 적층 고무베어링의 중앙에 원통형 납을 삽입함으로써 초기강성을 증가시켜, 빈번한 사용하중 하에서 구조물에 발생하는 비교적 과도한 횡변위를 구속할 수 있으며, 강한 지진파에 대해서는 이 납이 항복함으로써 에너지 소산능력을 향상시킨다.

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일본 의용소방대 실태의 분석 (Analysis of the Situation of the Volunteer Fire Brigade in Japan)

  • 이의평
    • 한국화재소방학회논문지
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    • 제25권6호
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    • pp.44-50
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    • 2011
  • 일본은 잦은 자연재해 등으로 인해 오래 전부터 지역주민에 의한 상부상조의 조직으로서 의용소방대가 발달되어 있다. 소방서가 설치되고 소방공무원이 충분히 있는 도시에서도 지진 또는 자연재해의 대응에 대비하여 의용소방대를 육성발전시키고 있다. 이 논문에서는 일본 의용소방대의 운영실태에 대해 분석하고 있다. 우리나라와 일본의 의용소방대 운영실태 비교를 통해 우리나라 의용소방대의 활성화를 위해서 도입할 만한 정책으로 의용소방대의 역할 검토, 장기근속을 장려하는 의용소방대원의 수당(5년 이상 근속시 퇴직보상금 지급, 계급별 출동수당 지급) 제도 도입, 초기대응장비의 배치, 교육제도 개선 등에 대해 제안하고 있다.