• 한국지진공학회논문집
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• 제13권4호
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• pp.15-23
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• 2009

본 연구에서는 원전 주제어실의 층 지진격리시스템에 대한 지진동 저감성능과 적용성을 평가하기 위해서 실험연구를 수행하였다. 층 지진격리시스템에 적용하기 위해서 납-고무 베어링(LRB)과 마찰진자장치(FPS)를 설계하고 제작하였다. 제어 캐비닛과 액세스 플로어로 구성된 원전 주제어실 부분 실험모형을 제작하여 납-고무 베어링과 마찰진자장치를 각각 설치하여 진동대 실험을 수행하여 지진응답특성을 비교, 평가하였다. 실험을 위해서 원전 주제어실의 운전기준지진(OBE)과 안전정지지진(SSE)의 수평방향 층응답 스펙트럼을 이용하여 인공지진 시간이력을 만들어서 진동대 실험에 사용하였다. 입력지진에 대한 실험모형의 지진응답은 마찰진자장치를 적용한 경우 상대적으로 우수한 지진동 저감특성을 나타냈다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.527-534
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• 2003

This paper presents the LRB-based hybrid base isolation systems employing additional active/semiactive control devices for seismic protection of cable-stayed bridges by examining the ASCE first generation benchmark problem for a cable-stayed bridge. In this study, ideal hydraulic actuators (HAs) and ideal magnetorheological dampers (MRDs) are considered as additional active and semiactive control devices, respectively. Numerical simulation results show that all the hybrid base isolation systems are effective in reducing the structural responses of the benchmark cable-stayed bridge under the historical earthquakes considered. The simulation results also demonstrate that the hybrid base isolation system employing semiactive MRBs is robust to the stiffness uncertainty of the structure, while the hybrid system with active HAs is not. Therefore, the LRB-based hybrid base isolation system employing MRDs could be more appropriate in real applications for full-scale civil infrastructures.

• 한국공간구조학회논문집
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• 제19권1호
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• pp.53-64
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• 2019

The objective of this study is to investigate the earthquake response for the design of 100m spanned single-layer lattice dome. The plastic hinge analysis and eigenvalue buckling analysis are performed to estimate the ultimate load of single-layered lattice domes under vertical loads. In order to ensure the stability of lattice domes, it is investigated for the plastic hinge progressive status by the pushover increment analysis considering the elasto-plastic connection. One of the most effective methods to reduce the earthquake response of large span domes is to install the LRB isolation system of a dome. The authors discuss the reducing effect for the earthquake dynamic response of 100m spanned single-layered lattice domes. The LRB seismic isolation system can greatly reduce the dynamic response of lattice domes for the horizontal and vertical earthquake ground motion.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.367-372
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• 2002

In these days, The base isolation system is often used to improve the seismic capacity of the structures instead of conventional techniques of strengthening the structural members. The purpose of this study is to evaluate dynamic properties and mechanical characteristics of the 10tonf-LRB(Lead-Rubber Bearing). Experimental studies were performed to obtain the hysteretic behavior, effective shear stiffness( $K_{eff}$), equivalent damping( $H_{eq}$ ), capacity of energy dissipation( $W_{D}$) of six 10tonf-LRB. Especially, in this study, the response of the LRB for high loading frequency(0.5Hz~3.0Hz) was estimated. The effective shear stiffness of the LRB decreases and the capacity of energy dissipation increases as the shear strain amplitude increases. But the shear behavior of the LRB is not affected sensitively by loading frequency.y.y.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.429-436
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• 2005

In this study, we made two types of main control room floor systems (Type I, Type II) and several shaking table tests with and without isolation system were conducted to evaluate floor isolation effectiveness of LRB(Lead Rubber Bearing). Both type showed large difference according to input earthquake signals, but showed little difference according to floor type. It is required to make LRB of which design frequency is below 1Hz when applied to main control room of NPP, but considering much difficulties in making such LRB, it is recommended that consideration should be taken into account when applied to main control room of NPP.

• 한국전산구조공학회논문집
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• 제24권2호
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• pp.157-165
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• 2011

지진하중이 가해지는 구조물의 동적응답을 줄이기 위해서 면진장치가 널리 사용되고 있다. 근래에 들어서는 면진층의 변위를 증가시키지 않으면서도 면진된 구조물의 동적응답을 효과적으로 줄일 수 있는 스마트 면진시스템에 대한 연구가 활발히 이루어지고 있다. 이에 본 연구에서는 지진하중을 받는 아치구조물의 동적응답을 저감시키기 위하여 스마트 면진시스템을 적용하였고 제어성능을 검토하였다. 스마트 면진시스템을 구성하기 위하여 4kN 용량의 MR 감쇠기와 저감쇠 탄성 고무베어링을 사용하였다. 제안된 스마트 면진시스템의 제어성능을 검토하기 위하여 최적설계된 LRB와 지진응답 제어성능을 비교하였다. 이를 위하여 KBC2009 설계응답스펙트럼에 맞추어 생성한 인공지진파를 지진하중으로 사용하였다. 스마트 면진시스템의 MR 감쇠기를 제어하기 위하여 퍼지제어기를 사용하였으며, 다목적 유전자알고리즘을 이용하여 최적화하였다. 수치해석결과 스마트 면진시스템을 사용하면 LRB를 사용한 경우와 비교하여 면진층 변위와 아치구조물의 지진응답을 크게 줄일 수 있음을 확인하였다.

• Smart Structures and Systems
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• 제17권5호
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• pp.691-708
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• 2016

Recently, number of smart material are investigated and widely used in civil construction and other industries. Present study investigates the application of smart semi-active piezoelectric friction damper (PFD) made with piezoelectric material for the seismic control of the horizontally curved bridge isolated with lead rubber bearing (LRB). The main aim of the study is to investigate the effectiveness of hybrid system and to find out the optimum parameters of PFD for seismic control of the curved bridge. The selected curved bridge is a continuous three-span concrete box girder supported on pier and rigid abutment. The PFD is located between the deck and abutments or piers in chord and radial directions. The bridge is excited with four different earthquake ground motions with all three components (i.e. two horizontal and a vertical) having different characteristics. It is observed that the use of semi-active PFD with LRB is quite effective in controlling the response of the curved bridge as compared with passive system. The incorporation of the smart damper requiring small amount of energy in addition with an isolation system can be used for effective control the curved bridge against the dynamic loading.

• Earthquakes and Structures
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• 제21권5호
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• pp.461-475
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• 2021

Strategic structures are a potential target of the growing terrorist attacks, so their performance under explosion hazard has been paid attention by researchers in the last years. In this regard, the aim of this study is to evaluate the blast-resistance performance of lead-rubber bearing (LRB) base isolation system based on a probabilistic framework while uncertainties related to the charge weight and standoff distance have been taken into account. A sensitivity analysis is first performed to show the effect of explosion uncertainty on the response of base-isolated buildings. The blast fragility curve is then developed for three base-isolated steel moment-resisting buildings with different heights of 4, 8 and 12 stories. The results of sensitivity analysis show that although LRB has the capability of reducing the peak response of buildings under explosion hazard, this control system may lead to increase in the peak response of buildings under some explosion scenarios. This shows the high importance of probabilistic-based assessment of isolated structures under explosion hazard. The blast fragility analysis shows effective performance of LRB in mitigating the probability of failure of buildings. Therefore, LRB can be introduced as effective control system for the protection of buildings from explosion hazard regarding uncertainty effect.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.553-560
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• 2001

To substantiate the application of LRB(Laminated Rubber Bearing) to the seismic isolation system, it is necessary to develop a seismic analysis method considering the non-linear behavior of LRBs, which may significantly affect the seismic responses. In this paper, seismic analyses and shaking table tests are carried out for a seismically isolated structure using four LRBs. The parameter equations of seismic isolation frequency are obtained from the shaking table tests and the quasi-static tests of LRB itself to investigate the effects of the LRB characteristics in the prediction of maximum peak acceleration responses by analysis. From the comparison of the maximum peak acceleration responses obtained from numerical analyses and experiments, it is verified that the horizontal stiffness variations of LRB should be carefully considered in seismic analysis to obtain more accurate results.

• 한국공간구조학회논문집
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• 제11권1호
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• pp.47-56
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• 2011

일반적으로 전단벽은 횡력저항 요소로서 널리 이용되고 있다. 대부분의 전단벽 구조물은 통로의 목적으로 개구부를 필요로 하게 되고 전단벽들 사이가 슬래브나 연결보로 연결된 병렬전단벽의 형태를 띠게 된다. 본 연구에서는 병렬전단벽 구조물의 연결보 중앙부에 LRB(Lead Rubber Bearing)를 도입하였고 이 시스템의 풍응답 저감성능을 검토하였다. 제안된 방법의 효과를 살펴보기 위하여 20층 및 30층 예제구조물을 구성하였고 인공풍하중을 작성하여 경계비선형 시간이력해석을 수행하였다. 제안된 방법이 풍하중을 받는 고층 병렬전단벽 구조물의 사용성 향상에 도움을 줄 수 있는지 평가하기 위하여 일본 진동성능평가기준을 적용하여 보았다. 해석결과 본 논문에서 제안하는 LRB를 사용하여 병렬전단벽을 연결하는 방식이 풍응답 제어성능 개선에 효과가 있는 것을 확인할 수 있었다.