• 국제초고층학회논문집
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• 제10권3호
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• pp.219-227
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• 2021

This building is a forty-eight story, 170 meters high multiple dwelling house with Dual Frame System (DFS), a coupled vibration system connecting two independent structures with hydraulic dampers. Generation of large deformation between two structures during earthquakes contributes to make the hydraulic dampers effective. To improve the aseismic performance more, this building adopts DFS hybrid system that consists of DFS and base isolation system. About typical floors, columns and beams are constructed with LRV precast concrete method that shorten the construction period greatly by integrating column-beam joints in column members.

• Steel and Composite Structures
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• 제22권6호
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• pp.1217-1238
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• 2016

Mega composite structure systems have been widely used in high rise buildings in China. Compared to other structures, this type of composite structure systems has a larger cross-section with less weight. Concrete filled steel tubular (CFST) laced column to box-beam connections are gaining popularity, in particular for the mega composite structure system in high rise buildings. To enable a better understanding of the destruction characteristics and aseismic performance of these connections, three different connection types of specimens including single-limb bracing, cross bracing and diaphragms for core area of connections were tested under low cyclic and reciprocating loading. Hysteresis curves and skeleton curves were obtained from cyclic loading tests under axial loading. Based on these tested curves, a new trilinear hysteretic restoring force model considering rigidity degradation is proposed for CFST laced column to box-beam connections in a mega composite structure system, including a trilinear skeleton model based on calculation, law of stiffness degradation and hysteresis rules. The trilinear hysteretic restoring force model is compared with the experimental results. The experimental data shows that the new hysteretic restoring force model tallies with the test curves well and can be referenced for elastic-plastic seismic analysis of CFST laced column to composite box-beam connection in a mega composite structure system.

• 한국건축시공학회지
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• 제8권2호
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• pp.113-119
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• 2008

Recently, fiber reinforced polymers(FRP) composite materials are used extensively in the rehabilitation of concrete structural members. A main application is to wrap beams and columns using the continuous fibers sheets to improve their strength and ductility. The corner chamfering affects significantly the performance of the continuous fibers sheets, and could lead to environmental problem with waste and dust. The main purpose of this paper is to verify the effect of corner conditions on the strength of the continuous fiber sheets, and to introduce new attached components which can avoid environmental problem. A total of 15 specimens were tested and carefully checked for three types of continuous fiber sheets(carbon, glass, and aramid) and three types of corner conditions(non-chamfering, chamfering, and device attaching). It is proved that the devices proposed in this research have some capabilities to use for RC member. But additional research will be needed for commercializing.

• Structural Engineering and Mechanics
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• 제65권5호
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• pp.557-572
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• 2018

The academic research works about liquid storage tanks are reviewed for the purpose of providing valuable reference to the engineering practice on their aseismic design. A summary of the performance of tanks during past earthquakes is described in this paper. Next, the seismic response of tanks under unidirectional earthquake is reported, supplemented with the dynamic response under multidirectional motions. Then, researches on the influence of soil-structure interaction are brought out to help modify the seismic design approach of tanks in different areas with variable properties of soils. Afterwards, base isolation systems are reported to demonstrate their effectiveness for the earthquake-resistant design of liquid storage tanks. Further, researches about the liquid-structure interaction are reviewed with description of simplified models and numerical analytical methods, some of which consider the elastic effect of tank walls. Moreover, the liquid sloshing phenomenon on the hydrodynamic behaviors of tanks is presented by various algorithms including grid-based and meshfree method. And then the impact of baffles in changing the dynamic characteristics of the liquid-structure system is raised, which shows the energy dissipation by the vortex motion of liquid. In addition, uplifting effect is given to enhance the understanding on the capacity of unanchored tanks and some assessment of their development. At last, the concluding remarks and the aspects of extended research in the field of liquid storage tanks under seismic loads are provided, emphasizing the thermal stress analysis, the replaceable system for base isolation, the liquid-solid interaction and dynamic responses with stochastic excitations.

• 한국공간구조학회논문집
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• 제13권3호
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• pp.45-55
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• 2013

The core aim of this paper is to empirically scrutinize a strength characteristic and ductility of the beam-column frame of reinforced with steel subjected to the cyclic lateral load. First and foremost, I the author embarks upon making four prototypes vis-$\grave{a}$-vis this research. Through this endeavour, the author has analysed cyclic behavior, fracture shape, ductility and energy dissipation of the normal beam-column frame and a beam-column frame of reinforced with steel. In addition, the survey has revealed the exact stress transfer path and the destructive mechanism in order to how much a beam-column frame of reinforced with steel has resistance to earthquake regarding all types of building, as well as school construction. To get the correct data, the author has compared the normal beam-column frame and three types of the beam-column frame of reinforced with steel following these works, the characteristic of cyclic behavior, destructive mechanism, ductility, and Energy dissipation of normal beam-column frame and a beam-column frame of reinforced with steel have been examined clearly.

• Earthquakes and Structures
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• 제23권4호
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• pp.363-371
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• 2022

Traditional metal dampers have disadvantages such as a higher yield point and inadequate adjustability. The experimental results show that the low yield point steel has superior energy dissipation hysteretic capacity and can be applied to seismic structures. To overcome these deficiencies, a novel compound metal damper comprising both low yield point steel plates and common steel plates is presented. The optimization objectives, including "maximum rigidity" and "full stress state", are proposed to obtain the optimal edge shape of a compound metal damper. The numerical results show that the optimized composite metal damper has the advantages such as full hysteresis curve, uniform stress distribution, more sufficient energy consumption, and it can adjust the yield strength of the damper according to the engineering requirements. In view of the mechanical characteristics of the compound metal damper, the equivalent model of eccentric cross bracing is established, and the approximate analytical solution of the yield strength and the yield displacement is proposed. A nonlinear simulation analysis is carried out for the overall aseismic capacity of three-layer-frame structures with a compound metal damper. It is verified that a compound metal damper has better energy dissipation capacity and superior seismic performance, especially for a damper with double-objective optimized shape.

• 한국지반공학회논문집
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• 제33권4호
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• pp.47-56
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• 2017

잔교식 안벽의 내진설계는 보통 다중모드 스펙트럼 해석과 같은 단순 동해석 방법을 적용하여 수행된다. 이러한 단순 해석법은 구조물의 한계상태를 평가하는데 유용할 수 있다. 그러나, 과거에 발생한 잔교식 안벽의 지진피해사례를 살펴보면, 기초지반의 변형 또는 지반-말뚝 사이의 동적 상호작용이 구조물의 전체 거동에 큰 영향을 미치는 것으로 나타났다. 이러한 거동은 지반-말뚝-구조물 동적 상호작용을 정밀하게 모사할 수 있는 비선형 유효응력 해석을 수행하여 평가할 수 있다. 본 연구에서는 잔교식 안벽의 내진성능을 평가할 수 있는 3차원 수치 모델링 기법을 선정하고, 이를 Hyogoken Nambu 지진(1995)시 고베항의 잔교식 안벽 피해사례에 적용하여 그 적용성을 검증하였다. 해석결과, 본 연구에서 적용한 수치 모델링 기법이 안벽의 지진피해 거동을 잘 모사할 수 있으며, 지반의 과잉간극수압증가 및 지반-구조물과의 동적 상호작용이 안벽의 지진거동에 큰 영향을 주는 것으로 나타났다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.282-286
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• 2000

In this paper, magneto-rheological(MR) damper is studied for vibration control of large infra structures under earthquake. Generally, active control devices need a large control force and a high power supply system to reduce the vibration effectively. Large and miss tuned control force may induce the dangerous situation such that the generated large control force acts to amplify the structural vibration. Recently, to overcome the weaknesses of the active control, the semi-active control method is suggested by many researchers. Semi-active control uses the passive control device of which the characteristics can be modified. Control force of the semi-active device is not generated from the actuator with power supply. It is generated as a dynamic reaction force of the device same as in the passive control case, so the control system is inherently stable and robust. Unlike the case of passive control, control force of semi-active control is adjusted depending on the measured response of the structure, so the vibration can be reduced more effectively against various unknown environmental loads. Magneto-rheological(MR) damper is one of the semi-active devices. Dynamic characteristics of the MR material can be changed by applying the magnetic fields. So the control of MR damper needs only small power. Response time of MR to the input voltage is very short, so the high performance control is possible. MR damper has a high force capacity so it is adequate to the vibration control of large infra structure. Because MR damper has a nonlinear property, normal control method used in active control may not be effective. Clipped optimal control, modified bang-bang control etc. have been suggested to MR damper by many researchers. In this study, sliding mode fuzzy control(SMFC) is applied to MR damper. Genetic algorithm is used for the controller tuning. To verify the applicability of MR damper and suggested algorithm, numerical simulation on the aseismic control is carried out. Simulation model is three-story building structure, which was used in the paper of Dyke, et al. The control performance is compared with clipped optimal control. The present results indicate that the SMFC algorithm can reduce the earthquake-induced vibration very effectively.

• 한국지진공학회논문집
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• 제6권2호
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• pp.9-19
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• 2002

강합성교각과 강교각은 철근곤크리트교각에 비해서 우수한 연성, 작은 단면 및 빠른 시공속도에도 불구하고 이 같은 장점들을 활용할 필요가 있는 도시지역에서조차 철근콘크리트교각의 대안으로서 활용되지 못하였다. 이 논문은 강합성교각과 강교각의 내진성능 평가에 관한 연속된 두편의 논문 중 첫편으로 강교각과 강합성 교각의 연성과 강성을 평가 비교하기 위해 수행한 준정적 반복재하실험을 대상으로 하였다. 기존의 강교각 및 강합성교각의 실험과 더불어 채움콘크리트와 하부 다이어프램간의 부작을 개선한 상세를 실험하였다. 또한, 강합성교각의 연성과 강성을 산정하기 위한 간편한 수치해석방법을 찾기 위해 비선형 스프링과 쉘요소를 사용한 해석을 시도하였다. 도시내의 전형적인 오버패스구간의 교각을 모델로 한 실험결과, 강합성교각은 강교각에 비해서 우수한 강성과 에너지 소산능력을 가지고 있는 것으로 나타났으며 채움콘크리트의 부착과 응력집중부의 상세를 개선시기는 것이 강합성교각의 연성과 강성을 증가시키는데 효과적인 것으로 나타났다. 시도된 수지해석방법은 강합성교각과 강교각의 거동을 완벽하게 모사하지는 못했지만 추가적인 연구가 진행되면 연성과 강성을 평가하는 간편한 방법으로 사용될 수 있는 것으로 판단된다.

• 콘크리트학회논문집
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• 제17권4호
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• pp.603-611
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• 2005

본 연구에서는 합리적인 내진설계기준의 정립을 위하여 철근콘크리트 교각의 내진성능에 영향을 미치는 주요 인자에 대하여 분석하였다. 주요 각국의 내진규정에서 내진성능을 발휘하기 위한 심부구속철근량을 규정함에 있어 다양한 요소들을 고려하고 있다. 하지만, 이러한 요소들이 합리적으로 고려되었는가에 대해서는 의문이 남는다. 따라서 본 연구에서 국내의 도로교설계기준, Eurocode 8 part2, NZS 3101, ATC-32 등의 설계기준을 비교분석하고, 기존 실험 연구 결과와 비교 분석하여 합리적인 영향인자들을 제안하고자 하였다. 연구결과에 따르면 원형 철근콘크리트 교각의 내진성능에 가장 지배적인 영향인자는 축하중비인 것으로 조사되었다. 따라서 심부구속철근비 산정식에 축하중비의 영향을 전혀 고려하고 있지 않는 현행 도로교설계기준에 축하중비를 도입해야 한다.