• Title/Summary/Keyword: Earthquake-proof

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The Study of Reinforcement through the Nonlinear Static Analysis and Inelastic Seismic Performance Evaluation in School Building (학교건물에 있어서 비탄성해석 및 비선형 정적해석을 통한 내진성능 평가에 따른 보강 연구)

  • Lee, Ho;Kwon, Young-Wook;Kim, Hong-Do
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.2
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    • pp.55-63
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    • 2012
  • This study is about earthquake-proof reinforcement through structural function evaluation of an school building. The purpose of this study is to comparatively analyze structure reinforcement measures in consideration of safety and usability through structural function evaluation of school buididng, to offer rational measures for earthquake-proof function and to provide help in maintaining safe structures against earthquake. For this purpose, was selected for this study as an existing school building, earthquake-proof function evaluation was conducted, and measures to reinforce earthquake-proof function was offered. As for the research method, the first and the second earthquake-proof function evaluations were conducted which is an existing reinforced concrete school building. Through the abovementioned methods, earthquake-proof function evaluation were conducted, the results were analyzed and the measure to reinforce earthquake-proof function were offered(Steel damper, Carbon plate stiffeners). The offered measure to reinforce earthquake-proof function was applied to the subject structure, and comprehensive results were derived from earthquake-proof function evaluation regarding before and after earthquake-proof function reinforcement.

Weight Drop Impact Tests of Earthquake-Proof Table (내진테이블의 중량물 낙하 충격실험)

  • Eom, Tae Sung;Huh, Seok Jae;Park, Tae Won;Lee, Sang Hyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.7
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    • pp.369-378
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    • 2018
  • Full-scale seismic retrofit of old and deteriorated masonry buildings requires a lot of cost and time. In such buildings, installing an emergency evacuation space can be considered as an alternative. In this study, requirements of the earthquake-proof table used as an emergency evacuation space for buildings hit by earthquake are investigated. Load conditions required for the table, including the impact effects due to building debris drop, are explained. To investigate the impact effects in more detail, weight drop test is performed for an prototype earthquake-proof table. In the test, the weight of the falling object and free fall height were considered as the main test parameters. The results showed that the duration of impact is very short (0.0226~0.0779sec), and thus the impact forces increase to 15.8~45.2 times the weight of the falling object. Based on these results, design considerations and performance verification criteria of the earthquake-proof table as an emergency evacuation space are given.

Analysis of earthquake countermeasure for electrical facility at building (건축물에 시설되는 수변전설비의 지진 대책에 대한 조사 분석)

  • Kim, Gi-Hyun;Lee, Sang-Ick;Jean, Hyun-Jae;Bae, Suk-Myong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.359-362
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    • 2008
  • Middle domestic the occurrence size which stews recently from the Korean Peninsula circumference country is augmenting on a large scale about earthquake about safe countermeasure part from the existing Natural Countermeasure Law 2008. Refers with the Earthquake Disaster Countermeasure Law to be new standard contents establishment by law and strengthened in March. Consequently the research is propelled about electric equipment earthquake-proof plan and countermeasure. The present paper investigated an equipment by domestic facility present condition about the change disappointment electric equipment which can supply all the member in the building an investigation analysis about problem point and improvement fact. Also about overseas electric equipment investigated about earthquake-proof plan relation system and facility present condition. Investigated the electric equipment earthquake-proof plan pertinent data which is advanced from like this existing nation and the equipment and application direction must apply to domestic presented. With character presents following the guide about electric equipment earthquake-proof plan becomes feed with the fact that will be able to use.

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Development of an Earthquake-Resistant Model for a High-Level Waste Disposal Canister (고준위 폐기물 처분용기 내진 해석 모델 개발)

  • Choi, Young-Chul;Yoon, Chan-Hoon;Kim, Hyun-Ah;Choi, Heui-Joo
    • Tunnel and Underground Space
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    • v.24 no.4
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    • pp.316-324
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    • 2014
  • In the underground 500 m depth, the high level radioactive waste disposal system is made by boring the tunnel in the base rock and putting the high level waste disposal canister that is the surrounding form with the buffer material. According to the many statistics, it is the tendency that the earthquake increases in the Korean peninsula every year. In case that the earthquake is generated, the disposal canister in the rock mass can be broken due to the shearing force in the underground. Furthermore, a major environmental problems can be caused by the radioactive harmful substances. In this study, the earthquake-proof type buffer material was developed with the protection method safely on the earthquake. The main parameter having an effect on the earthquake-resistant performance was analyzed and the earthquake-proof type buffer material was designed. The shear analysis model was developed and the performance of the earthquake-proof type buffer material was evaluated by using ABAQUS.

Piecewise exact solution for seismic mitigation analysis of bridges equipped with sliding-type isolators

  • Tsai, C.S.;Lin, Yung-Chang;Chen, Wen-Shin;Chiang, Tsu-Cheng;Chen, Bo-Jen
    • Structural Engineering and Mechanics
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    • v.35 no.2
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    • pp.205-215
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    • 2010
  • Recently, earthquake proof technology has been widely applied to both new and existing structures and bridges. The analysis of bridge systems equipped with structural control devices, which possess large degrees of freedom and nonlinear characteristics, is a result in time-consuming task. Therefore, a piecewise exact solution is proposed in this study to simplify the seismic mitigation analysis process for bridge systems equipped with sliding-type isolators. In this study, the simplified system having two degrees of freedom, to reasonably represent the large number of degrees of freedom of a bridge, and is modeled to obtain a piecewise exact solution for system responses during earthquakes. Simultaneously, we used the nonlinear finite element computer program to analyze the bridge responses and verify the accuracy of the proposed piecewise exact solution for bridge systems equipped with sliding-type isolators. The conclusions derived by comparing the results obtained from the piecewise exact solution and nonlinear finite element analysis reveal that the proposed solution not only simplifies the calculation process but also provides highly accurate seismic responses of isolated bridges under earthquakes.

Dynamic performance of girder bridges with explosion-proof and aseismic system

  • Wang, Jingyu;Yuan, Wancheng;Wu, Xun;Wei, Kai
    • Structural Engineering and Mechanics
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    • v.61 no.3
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    • pp.419-426
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    • 2017
  • Recently, the transportation of dangerous explosive goods is increasing, which makes vehicle blasting accidents a potential threat for the safety of bridge structures. In addition, blasting accidents happen more easily when earthquake occurs. Excessive dynamic response of bridges under extreme loads may cause local member damage, serviceability issues, or even failure of the whole structure. In this paper, a new explosion-proof and aseismic system is proposed including cable support damping bearing and steel-fiber reinforced concrete based on the existing researches. Then, considering one 40m-span simply supported concrete T-bridge as the prototype, through scale model test and numerical simulation, the dynamic response of the bridge under three conditions including only earthquake, only blast load and the combination of the two extreme loads is obtained and the applicability of this explosion-proof and aseismic system is explored. Results of the study show that this explosion-proof and aseismic system has good adaptability to seism and blast load at different level. The reducing vibration isolation efficiency of cable support damping bearing is pretty high. Increasing cables does not affect the good shock-absorption performance of the original bearing. The new system is good at shock absorption and displacement limitation. It works well in reducing the vertical dynamic response of beam body, and could limit the relative displacement between main girder and capping beam in different orientation so as to solve the problem of beam falling. The study also shows that the enhancement of steel fibers in concrete could significantly improve the blast resistance of main beam. Results of this paper can be used in the process of antiknock design, and provide strong theoretical basis for comprehensive protection and support of girder bridges.

Seismic Retrofit after 921 Earthquake

  • Tsai, C.S.
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.18-20
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    • 2000
  • At 1:47 a.m, local time on September 21, 1999, a strong earthquake measured 7.3 on the Richter scale struck central Taiwan evoking another two earthquakes a few seconds late to wake up unprepared people of this small island. It caused 2,465 people killed 11,305 injured about 10,000 buildings collapsed and around 41,000 severely damaged, The major concerns after the earthquake are how to have learned from this natural disaster and how to rebuild earthquake-proof buildings without rendering up safety within reasonable costs. Inevitable actions for redrafting the building codes have been taken to re-strengthen the existing and new structures. Structural analysis tools and computer programs adopted by most practicing engineers have been re-examined to take into account the effects of the vertical component of ground shakings on structural responses. Most private structures were repaired by traditional methods without considering upgrading seismic resistibility because of economical reasons. Buildings open to the public are under consideration possibly enforced by making regulations to be upgraded to satisfy revised building codes. In addition new rehabilitation technologies such as structural control have been moving much faster than before and have become accepted by the public due to frequent reports by media and specialists. Building codes related to base isolators and energy absorption systems are still under legislation and expected to be published soon. Most of the new structures under construction designed by the building codes promulgated before the earthquake have been reconsidered to comply with the new codes even though it is not compulsory. Efforts have been made by the government engineering and research communities and universities in an attempt to reduce structural damage for future earthquakes and to construct if possible Taiwan as an earthquake-proof island.

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Seismic behavior of structures isolated with a hybrid system of rubber bearings

  • Chen, Bo-Jen;Tsai, C.S.;Chung, L.L.;Chiang, Tsu-Cheng
    • Structural Engineering and Mechanics
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    • v.22 no.6
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    • pp.761-783
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    • 2006
  • The enlargement of interest in base isolators as an earthquake-proof design strategy has dramatically accelerated experimental studies of elastomeric bearings worldwide. In this paper, a new base isolator concept that is a hybrid system of rubber bearings is proposed. Uniaxial, biaxial, and triaxial shaking table tests are also performed to study the seismic behavior of a 0.4-scale three-story isolated steel structure in the National Center for Research on Earthquake Engineering in Taiwan. Experimental results demonstrate that structures with a hybrid system of rubber bearings composed of stirruped rubber bearings and laminated rubber bearings can actually decrease the seismic responses of the superstructure. It has been proved through the shaking table tests that the proposed hybrid system of rubber bearings is a very promising tool to enhance the seismic resistance of structures. Moreover, it is demonstrated that the proposed analytical model in this paper can predict the mechanical behavior of the hybrid system of rubber bearings and seismic responses of the base-isolated structures.

Assessment of the Strong Motion Duration Criterion of Synthetic Accelerograms (내진설계를 위한 인공지진파 강진지속시간 기준의 평가)

  • Huh, Jung-Won;Jung, Ho-Sub;Kim, Jae-Min;Chung, Yun-Suk
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.133-140
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    • 2006
  • This paper addresses a fundamental research subject to complement and improve current domestic design specifications for the strong motion duration criterion and the envelop function of artificial accelerograms that can be applied to the earthquake-proof design of nuclear structures. The criteria for design response spectra and strong motion duration suggested by WRC RG 1.60 and ASCE Standard 4-98 are commonly being used in the profession, and they are first compared with each other and reviewed. By applying 152 real strong earthquake records that are over magnitude of 5 in the rock sites to the strong motion duration criterion in ASCE 4-98, an empirical regression model that predicts the strong motion duration as a function of earthquake magnitude is then developed. Using synthetically generated earthquake time histories for the five cases whose strong motion durations vary from 6 to 15 seconds, a seismic analysis is conducted to identify effects of the strong motion durations on the seismic responses of nuclear structures.

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