• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.455-456
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• 2009

최근 국내에서 내진성능평가를 위한 실험 시 구조물의 크기, 실험장비의 성능 등 여러 가지 제약 여건을 극복하고자 축소모형을 통하여 유사동적실험과 진동대실험을 수행하고 있지만 상사법칙에 관한 연구는 미비한 실정이다. 이에 대해 경제성과 신뢰성을 갖는 적절한 상사법칙을 제안하고자 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.1-4
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• 2005

To investigate the effective seismic strengthening methods for masonry walls in developing countries, a total of four confined masonry (CM) walls were constructed and tested. In order to investigate the effect of the height of application point of lateral loads and reinforcing steel bars in walls and columns for the improvement of the seismic behavior of confined concrete block masonry walls, an experimental research program is conducted. The heights of inflection point considered were 0.67 and 1.11 times the height of the wall measured from the top of foundation beam. The constant vertical axial stress applied was 0 MPa. During the test, cracking patterns, load-deflection data, and strains in reinforcement and walls in critical locations was measured. From test data, it was showed that the seismic performance of confined concrete block masonry walls was significantly affected by test variables.

• 한국구조물진단유지관리공학회 논문집
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• 제26권5호
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• pp.74-85
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• 2022

이 논문의 목적은 MCE를 적용한 콘크리트 중력식 댐의 동적소성해석에 의한 내진성능평가 수행 시 입력변수, 성능수준 평가 방법에 대한 현행 기준의 적용성을 검토하고 개선안을 제시하는 것이다. 이를 위하여 국내 콘크리트 중력식 댐을 대상 시설로 선정하여 다양한 조건으로 동적소성해석을 수행하였으며 입력변수인 콘크리트 인장강도, 파괴에너지 등에 대한 적용성을 검토하였다. 중력식 댐체 저면의 균열이 활동의 안정성 미치는 영향을 분석하여 저수기능 확보에 필요한 성능수준 평가 방법의 개선안을 도출하였다. 연구 결과 개선사항을 적용할 경우 MCE를 적용한 현행 내진성능평가 방법보다 합리적인 평가결과를 도출하는 효과가 있을 것이다.

• 한국방재안전학회논문집
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• 제13권3호
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• pp.1-14
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• 2020

본 연구는 국가산업단지 지진재난 안전관리 문제점 도출 및 개선방안 제시를 목적으로 수행되었다. 지진재난 안전관리 문제점을 조사하기 위하여 한국산업단지공단의 안전관리 운연현황 및 실무자 면담조사를 수행하였다. 또한, 전국 국가산업단지 28개소를 대상으로 내진설계 적용실태조사를 수행하였다. 상기 과정에서 도출된 문제점을 통합 정리한 후 전문가 의견 등을 반영하여 내진관련 법적규제 강화 등의 5가지 항목으로 분류된 개선방안을 제시하였다. 본 연구에서 제시한 개선방안은 향후 국가산업단지 내진성능 향상을 위한 정책수립 자료로 활용할 수 있을 것으로기대된다.

• 한국지진공학회논문집
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• 제23권1호
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• pp.1-8
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• 2019

In this study, the effectiveness of a multi-action hybrid damper (MHD) composed of lead rubber bearing (LRB) and friction pad was verified in terms of seismic performance improvement of a frame structure. The LRB and the friction elements are connected in series, so the LRB governs the intial small deformation and the friction determines large deformation behavior. Cyclic loading tests were conducted by using a half scale steel frame structure with the MHD, and the results indicated that the structure became to have the stable trilinear hysteresis with large initial stiffness and first yielding due to the LRB, and the second yielding due to the friction. The MHD could significantly increase the energy dissipation capacity of the structure and the hysteresis curves obtained by tests were almost identical to the analytically estimated ones.

• 한국안전학회지
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• 제37권3호
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• pp.45-51
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• 2022

This paper focuses on a recently proposed asymmetric base-isolation coupling control system (ABiCS) for the vibration control of adjacent twin buildings. The ABiCS consists of inter-story diagonal dampers, a connecting damper between the two buildings, and a seismic isolation device at the base floor of one building. To investigate the control characteristics of ABiCS, a parametric study was performed by numerically simulating the 20-story twin buildings. In the parametric study, the control capacities of the inter-story diagonal dampers, connecting damper, and seismic isolation device were considered as varying parameters. The parametric study results indicate that the connecting damper between the two buildings reduces the responses of both buildings only at optimal or near-optimal capacity. In addition, adjusting the stiffness of the base isolation is found to be the most effective method for improving seismic performance and achieving cost-effectiveness. Accordingly, we presented a scenario-based performance improvement approach in which reducing the stiffness of the base isolation device could be an effective technique to improve the seismic performance of both buildings. However, note that checking the maximum allowable displacement of the base isolation device is essential.

• Earthquakes and Structures
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• 제17권2호
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• pp.233-244
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• 2019

In this work, we have studied the effects of different soil thicknesses, haunch heights, reinforcement forms and construction technologies on the seismic performance of a composite precast fabricated utility tunnel by pseudo-static tests. Five concrete specimens were designed and fabricated for low-cycle reciprocating load tests. The hysteretic behavior of composite precast fabricated utility tunnel under simulated seismic waves and the strain law of steel bars were analyzed. Test results showed that composite precast fabricated utility tunnel met the requirements of current codes and had good anti-seismic performance. The use of a closed integral arrangement of steel bars inside utility tunnel structure as well as diagonal reinforcement bars at its haunches improved the integrity of the whole structure and increased the bearing capacity of the structure by about 1.5%. Increasing the thickness of covering soil within a certain range was beneficial to the earthquake resistance of the structure, and the energy consumption was increased by 10%. Increasing haunch height within a certain range increased the bearing capacity of the structure by up to about 19% and energy consumption by up to 30%. The specimen with the lowest haunch height showed strong structural deformation with ductility coefficient of 4.93. It was found that the interfaces of haunches, post-casting self-compacting concrete, and prefabricated parts were the weak points of utility tunnel structures. Combining the failure phenomena of test structures with their related codes, we proposed improvement measures for construction technology, which could provide a reference for the construction and design of practical projects.

• 한국안전학회지
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• 제31권3호
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• pp.68-74
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• 2016

This paper presents a new strengthening method of underground box structures against seismic loads for anti-seismic capacity improvement. A threaded steel member with pressure devices(so called 'Pre-flexed member system') is used to improve seismic capacity of the RC box structure. The pre-flexed member system is fixed the corner of opening after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. Two bracing types of strengthening methods were used; conventional bracing method and I-bracing pressure system. For the performance evaluation, seismic analyses were performed on moment and shear resisting structures with and without strength member system. Numerical results confirmed that the proposed pre-flexed member system can enhance the seismic capacity of the underground RC box structures.

• 한국지반신소재학회논문집
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• 제18권4호
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• pp.151-165
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• 2019

본 연구에서는 저유동성 몰탈 채움을 통한 기존 항만 구조물의 내진성능 향상을 위해 시공 위치에 따라 4가지(자중증가, 활동력 감소 등) 보강방안을 제시하였으며, 이론적 방법 및 수치해석적 방법으로 보강 시 효과(안정성, 시공성, 경제성)를 분석하여 최적 방안을 제시하였다. 본 연구 결과 인공지진파를 적용한 동적 시간이력해석을 수행한 결과 보강 후 수평변위는 보강 전 수평변위에 비해 감소하였으나 보강 방안별 지진시 변위 억제 효과는 큰 차이가 없는 것으로 평가되었다. 강도감소법과 한계평형해석법을 적용하여 원호활동 파괴특성을 검토한 결과 수동말뚝 형태의 개량 방안이 다른 보강방법에 비해 안전성이 높은 것으로 평가되었다. 이는 보강체로 인해 활동 파괴면의 전단강도가 증가하였기 때문이다. 또한, 시공성 및 경제성을 분석한 결과 토압 저감형태(Type 02)와 수동말뚝 형태(Type 03)가 우수한 것으로 나타났다. 다만, 수동말뚝 형태의 경우, 설계법 적용 사례가 미미하고, 지반 조건에 따라 시공이 불가하거나 경제성이 급격히 저감되는 등 여러 가지 제약조건을 가지고 있어 적용시 주의가 요구된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.109-114
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• 2000

Recently, it is required to improve the structural performance, such as durability and earthquake resistant capacity due to the deterioration of structural components in the existing reinforced concrete building with the old aging and transition of design code. Therefore, the new technology should be developed, such as seismic retrofit and improvement of structural performance in the existing reinforced concrete building. This analytical study was performed to verify the effects of basic and reinforcing system in the reinforced concrete building. The analytical results by nonlinear finite element method were compared with the experimental results and the comparisons are judged to be good.