• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.391-398
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• 2000

To evaluate the seismic performance of a base isolated building accurate analytical model should be selected. The analytical results such as reduced accelerations member forces and relative displacements of the superstructure of the base isolated building are only meaningful when the analytical model is close enough to the real structure. Real size one bay-two story steel frame and two kinds of seismic isolators(laminated elastomeric bearing and lead-rubber bearing) are designed. manufactured and constructed in the laboratory. Free vibration tests using fuse bars were conducted to evaluate the change of dynamic characteristics(period and damping) before and after base isolation of the steel frame. The experimental results of free vibration tests were also used as a bench mark for adjusting the selected analytical modeling to real base isolated steel frame.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.288-294
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• 2003

Increasing the volume of traffic on the roads causes social and economical problems such as increasing air-pollution and distribution cost. Prefabricated light weight bridge becomes a possible solution for these problems in the urban area where it is difficult to construct new one or expend the existing road. There are some merits in this kind of bridge. First, the design live and dead loads are minimized by allowing only passenger cars. Second employing prefabrication construction scheme reduces the construction time. Third, there is no need to buy land if the elevation road is placed on the top of existing one. In seismic design of bridges, base isolation has been an effective solution when the bridge has stiff piers and a heavy superstructure. The prefabricated light weight bridge has different dynamic characteristics from the ordinary bridges. In this paper, the applicability of base isolators such as lead rubber bearing and elastomeric bearing, to prefabricated light weight bridge is examined.

• Earthquakes and Structures
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• v.16 no.6
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• pp.665-677
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• 2019

This study utilizes large-scale shake table test to investigate the seismic performance of an isolated bridge with lead rubber bearings crossing an active fault. Two transverse restraining systems with and without shear keys are tested by applying spatially varying ground motions. It is shown that the near-fault span exhibits larger bearing displacement than the crossing-fault span. Bridge piers away from the fault rupture are more vulnerable than those adjacent to the fault rupture by attracting more seismic demand. It is also verified that the shear keys are effective in restraining the bearing displacement on the near-fault span, particularly under the large permanent ground displacement.

• Structural Engineering and Mechanics
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• v.85 no.2
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• pp.265-274
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• 2023

The spherical steel bearings (SSBs) has been gradually replaced traditional rubber bearings and extensively applied to high-speed railway (HSR) bridges in China, due to their durability and serviceability. Nevertheless, SSB is generally simplified to the ordinary constraints in the finite element model, which cannot reflect its detailed mechanical characteristics, especially its seismic performance. To provide a more precisely simulation, an innovative and simplified finite element simulation method is proposed and the combined element group is developed in ANSYS. The primary parameters were determined by means of the performance test of SSB. The finite element model of SSB applied to a single-span HSR simply supported girder bridge was established through the proposed method. The seismic performance of the SSB was further investigated. A shake table test was conducted to evaluate the accuracy of the proposed simulation method. It is found that the numerical results could have a good agreement with the experiment, namely, the proposed method is feasible and efficient.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.455-462
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• 2000

In this study seismic response of a base-isolated bridge for soil types is compared. Bilinear model is used for lead rubber bearing(LRB). Accelerograms whose response spectrum matches the design spectrum for soil types are used as earthquake ground excitation. Nonlinear time history analyses using the SAP2000 program is performed. The results show that seismic response of a base-isolated bridge is increased as the soil becomes soft.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.122-129
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• 1995

The seismic behavior of a rectangular liquid container with high damping laminated rubber bearing is investigated through the scaled model tests. The results are compared with those for non-isolated model, and those by analytical methods. It is shown that the optimum dynamic properties of isolation system can reduce the acceleration response in the superstructure significantly and prevent the amplification of sloshing height.

• Computational Structural Engineering
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• v.5 no.4
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• pp.41-45
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• 1992

본 실험에서는 가장 널리 쓰이는 base isolator의 한 종류로서 laminated rubber bearing을 제작하여 정적 및 동적 특성실험을 수행하였다. 앞에서 간략하게 언급한 실험결과에 대한 분석자료는 상부구조물과 기초와의 분리를 목적으로 본 실험에서 제작한 base isolator의 활용가능성을 검증하였다. 일반적으로 base isolator가 갖는 특성을 대부분 포함하고 있지만 본 실험결과에서 얻은 개선점은 i) 수직강성의 보강 ii) mounting plate와의 볼트연결부분 보완 iii) 최대전단변형을 증가시키기 위해 base isolator의 전체높이 조정 등으로 요약할 수 있다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.391-400
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• 2002

In this study, the standardized design methods and procedures are proposed for bridge LRB(Lead Rubber Bearing) design. The bridge LRB design program is developed according to these methods and procedures, on the basis of "AASHTO Guide Specifications for Seismic Isolation Design, 1999". This program is applied to Young-Dong bridge.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.334-343
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• 2003

본 논문의 목적은 스팅베어링의 기존교량과 납-고무베어링(Lead-Rubber Bearing)으로 내진 보강된 교량에 대해서 갭(Gap)의 크기가 교량의 지진 취약도에 미치는 영향에 대해서 평가하였다. 이를 위해서 다경간 단순교(Multi-Span Simply Supported Bridge)와 다경간 연속교(Muti-Span Continuous Bridge)를 대상으로 취약도 분석을 실시하였다 또한 다양한 크기의 갭사이즈를 도입하여 해석을 실시하였다. 이를 통해서 갭사이즈의 변화가 각 교량의 구성품에 미치는 영향을 확률적으로 평가할 수 있었고, 합성된 취약도 곡선을 이용하여 최적의 갭사이즈를 확정할 수 있었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.401-406
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• 2013

This paper presents experimental evaluation of IRE (isolation roller bearing) seismic isolation device. From the combination of base isolation on the IRE system displacement response spectrum and acceleration response spectrum, the compressive strength and the coefficient of friction experiments. Also the IRE system is evaluated by environment test according to KS standards. Both the resonance and seismic experiments using a combination of the IRE and Natural Rubber Bearing (NRB) are performed in order to analyze the seismic isolation of the IRE system dynamic characteristics. For the given load and exciting frequency, the resonant frequency becomes lower, but the resonant magnification remains to be same. However, it is shown that when we consider the IRE only, the vibration on the table with the horizontal movement and the independent horizontal displacement due to the rolling motion of the plate and roller are significantly reduced. This result verifies that the proposed optimal design method of the IRE system is very effective.