• Title/Summary/Keyword: 내진보강

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A Development of Seismic Rehabilitation Method of RC Buildings Strengthened with X-Bracing Using Carbon Fiber Composite Cable (X-가새형 탄소섬유케이블을 이용한 중·저층 철근콘크리트 건물의 내진보강법 개발)

  • Lee, Kang-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.1-9
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    • 2014
  • Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. In this study, a non-compression cross-bracing system using the Carbon Fiber Composite Cable (CFCC), which consists of CFCC bracing and bolt connection was proposed to replace the conventional steel bracing. This paper presented the seismic resistance of a reinforced concrete frame strengthened using CFCC X-bracing. Cyclic loading tests were carried out, and the maximum load carrying capacity and ductility were investigated, together with hysteresis of the lateral load-drift relations. Test results revealed that the CFCC X-bracing system installed RC frames enhanced markedly the strength capacity and no buckling failure of the bracing was observed.

Seismic Performance Evaluation of Medium-and Low-rise R/C Buildings Strengthened with RCSF External Connection Method by Pseudo Dynamic Test (유사동적실험에 의한 RCSF 외부접합공법으로 내진보강 된 중·저층 철근콘크리트 건물의 내진성능 평가)

  • Lee, Kang-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.1
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    • pp.13-22
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    • 2015
  • In this study, a new RCSF (Reinforced Concrete Steel Frame) external connection method is proposed for seismic strengthening of medium-and low-rise reinforced concrete buildings. The RCSF method, proposed in this study, is capable of carrying out the seismic retrofitting construction while residents can live inside structures. The method is one of the strength design approach by retrofit which can easily increase the ultimate lateral load capacity of concrete buildings controlled by shear. The pseudo-dynamic test, designed using a existing school building in Korea, was carried out in order to verify the seismic strengthening effects of the proposed method in terms of the maximum load carrying capacity and ductility. Test results revealed that the proposed RCSF strengthening method installed in RC frame enhanced conspicuously the strength and displacement capacities, and the method can resist markedly under the large scaled earthquake intensity level.

Retrofit Prioritization of Highway Network considering Seismic Risk of System (지진 위험도를 고려한 도로 교통망의 내진보강 우선순위 결정)

  • Na, Ung-Jin;Park, Tae-Won;Shinozuka, Masanobu
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.6
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    • pp.47-53
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    • 2008
  • This research focuses on the issue of seismic retrofit prioritization based on the Caltrans' highway network serving Los Angeles and Orange counties. Retrofit prioritization is one of most important problems in earthquake engineering, and it is a problem that most decision makers face in the process of resource allocation. This study demonstrates the methods of prioritized resource allocation in the process of retrofitting a regional highway network. For the criteria of a retrofit ranking, seismic vulnerability and the importance of network link are first introduced. Subsequently, link-based seismic retrofit cases are simulated, investigating the effects of the seismic retrofit in terms of seismic performance, such as driver's delay. In this study, probabilistic scenario earthquakes are used to perform a probabilistic seismic risk analysis. The results show that the retrofit prioritization can be differently defined and ranked depending on the stakeholders. This study provides general guidelines for prioritization strategy for the effective retrofitting of a highway network system.

Seismic Performance Evaluation of Seismic Strengthening Method using SRCF External Connection of Medium and Low-rise R/C Buildings (중·저층 철근콘크리트 건물의 SRCF 외부접합 내진보강공법의 내진성능 평가)

  • Lee, Kang-Seok;Jung, Jue-Seong;Lee, Jong-Kweon
    • Journal of the Korea Concrete Institute
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    • v.27 no.2
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    • pp.147-155
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    • 2015
  • A new SRCF (Steel Reinforced Concrete Frame) external connection method for seismic strengthening of medium-and low-rise reinforced concrete buildings is reported in this paper. The SRCF method, proposed in this study, is capable of carrying out the seismic retrofitting construction while residents can live inside building. The method is one of the strength design approach by retrofit which can easily increase the ultimate lateral load capacity of concrete buildings controlled by shear. The pseudo-dynamic test, designed using a existing school building in Korea, was carried out in order to verify the seismic strengthening effects of the proposed method in terms of the maximum load carrying capacity and deformation. Test results revealed that the proposed SRCF strengthening method installed in RC frame enhanced conspicuously the strength and deformation capacities, and the method can resist markedly under the large scaled earthquake intensity level.

Advanced Seismic Retrofit Priority Decision For Seismic Performance Estimation of Existing Bridges (기존 교량의 내진성능평가를 위한 개선된 내진보강 우선순위 결정)

  • Park, Kwang-Soon;Ju, Hyeong-Seok;Choi, Hong-Cheol;Kim, Ick-Hyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.6
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    • pp.47-57
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    • 2009
  • Existing bridges are classified into 4 retrofit groups using the current preliminary screening method, considering key terms such as seismicity, vulnerability and social impact effect. However, some irrationality was found when the current method was applied to 442 existing bridges. As a result, it was determined that quantification and a more detailed classification of seismicity were required. The estimation of the vulnerability of box girder bridges having a long span length should be improved, as this showed a tendency to underestimate. It was also necessary to increase the level of social impact effect to that of vulnerability. In this study, an improved preliminary screening method has been proposed on the basis of the estimation results of existing bridges.

Performance Evaluation of Earthquake Resistant Caisson Type Quay Walls (케이슨식 안벽의 내진보강 성능 평가 -수치해석적 측면에서-)

  • 권오순;황성춘;박우선
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.129-139
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    • 2000
  • The liquefaction of reclaimed land generally caused the harbor facilities to hazards. In Korea, the major harbor quay walls are gravity type and the gravity quay wall is not a good earthquake resistant structure. Recently, various earthquake resistant quay walls have been suggested, but the study on the efficiency of reinforced quay wall was not much performed. In this study, numerical analysis is carried out for performance evaluation of easily adoptable earthquake resistant quay walls. The results of numerical analysis are compared with shaking table test that is performed at the same cross-section.

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Retrofit Measures Based on Seismic Retrofit Priority of Existing Bridges (교량의 내진보강 우선순위를 이용한 합리적인 보강방안 선정기법)

  • Lee, Sang-Woo;Kim, Sang-Hyo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.3
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    • pp.77-86
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    • 2004
  • The retrofit priority of existing and retrofitted bridges is examined and compared to determine effectively the seismic retrofit method of bridges. For the retrofit prioritization of bridges a quantitative procedure is proposed firstly based on seismic damage probabilities and total failure cost due to the damage of seismic vulnerable components. Using the proposed procedure, the retrofit priority of four typical girder-type bridges is determined. In addition, the ranking indices of bridges retrofitted by steel jackets and cable restrainers are revaluated for comparing with the results of existing bridges. Application of retrofitting method can considerably decreases damage possibilities of retrofitted components but may increases those of adjacent vulnerable components. Therefore, the seismic retrofitting effects based on the global motions of existing and retrofitted bridges should be examined to determine efficiently the retrofitting method. For evaluating the retrofitting effects the ranking indices obtained from the proposed procedure is found to be utilized effectively.

Improvement Plan of Seismic Retrofitting Support System for Establishing Earthquake Disaster Prevention Policy (지진 방재정책 수립을 위한 건축물 내진보강 지원제도 개선방안)

  • Hur, Jin-Ho;Kim, Hee-Kyu;Shin, Min-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.7
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    • pp.611-617
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    • 2017
  • In recent decades, unpredictable earthquakes around the world have caused massive damage. The incidence of earthquakes in Korea that are larger than M5.0 has increased the social demand for earthquake policies. As the seismic performance of buildings has been proven to be the most effective damage mitigation responsibility from past earthquake damage cases, the US and Japan are implementing a seismic retrofitting support system. In Korea, this is being implemented through tax benefits, but it is being neglected by the owners of private buildings. As a solution to this problem, this paper reviews, compares, and analyzes the domestic and overseas seismic retrofitting support systems, and suggests ways to improve the policy and support system for revitalizing the seismic retrofitting of private buildings based on the results.

Seismic Retrofit Design of RHS Column-to-H Beam Connections (RHS 기둥-H형강보 접합부의 내진보강 설계)

  • Kim, Young Ju;Oh, Sang Hoon
    • Journal of Korean Society of Steel Construction
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    • v.20 no.4
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    • pp.529-537
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    • 2008
  • The objective of this paper is to propose retrofit design methods of theRHS column-to-H beam connections with floor slabs. Referring to previous studies on the retrofitting of moment connections, it is clear that connections retrofitted with a stiffened RBS (SR) or a lengthened horizontal stiffener (LH) has an effect on decreasing the stress/strain concentration. A new design procedure using these two retrofitting methods was thus presented. In addition, this paper addressed various design or detailing options and recommended a procedure for designing the improved retrofitting method of steel moment connections. Finally, a pilot test was conducted to verify the design procedure.

Analytical Study for Seismic Retrofit of SMRFs Connections (철골모멘트접합부의 내진보강에 관한 해석적 연구)

  • Oh, Sang Hoon;Kim, Young Ju
    • Journal of Korean Society of Steel Construction
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    • v.20 no.3
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    • pp.445-454
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    • 2008
  • Based on previous research on steel moment connections, experimental and analytical results showed that the deformation capacity was poor in specimens using RHS columns and with conventional weld access holes and strain concentration at the end of beam is influenced by the efficiency in transmitting the moment in the web of beam through the beam-to-column joint. This paper is focused on the retrofitting of pre-Kobe steel moment frame connections using a stiffened RBS and a welded horizontal stiffener. These retrofitting methods were considered only in beam bottom flange. A parametric study was performed using nonlinear finite element analysis to elucidate and improve the retrofit methods of connections.