• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 춘계학술대회 논문집
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• pp.426-431
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• 2001

Seismic performance of base isolated rigid-mass model were studied through shaking table tests. Friction pendulum systems (FPS), pure-friction systems with laminated rubber bearing (LRB) were selected for the comparison of performance. Performance of specially designed isolation systems were tested statically using actuator and dynamically using shaking table. Numerical methods were developed to simulate the nonlinear behavior of the frictional base isolation systems. Two models were considered. one is modified Bouc-Wen model considering breakaway coefficient of friction and the other is classical Coulomb model. The results of numerical methods are found to be in very good agreement with test results.

• Earthquakes and Structures
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• 제17권4호
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• pp.425-434
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• 2019

The most effective passive vibration control and seismic resistance options in a reinforced concrete (RC) high-rise building (HRB) are the base isolation and the tuned mass damper (TMD) system. Many options, which may be suitable or not for different soil types, with different types of bearing systems, like rubber isolator, friction pendulum isolator and tension/compression isolator, are investigated to resist the base straining actions under five different earthquakes. TMD resists the seismic response, as a control system, by reducing top displacement or the total movement of the structure. Base isolation and TMDs work under seismic load in a different way, so the combination between base isolation and TMDs will reduce the harmful effect of the earthquakes in an effective and systematic way. In this paper, a comprehensive study of the combination of TMDs with three different base-isolator types for three different soil types and under five different earthquakes is conducted. The seismic response results under five different earthquakes of the studied nine RC HRB models (depicted by the top displacement, base shear force and base bending moment) are compared to show the most suitable hybrid passive vibration control system for three different soil types.

• 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.

• Earthquakes and Structures
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• 제26권6호
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• pp.463-475
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• 2024

The study aims to investigate the pounding that occurs between the isolator's ring and slider of isolated structures resulting from excessive seismic excitation, while considering soil-structure interaction. The dynamic responses and poundings of structures subjected a series seismic records were comparatively analyzed for three different soil types and fixed-base structures. A series of parametric studies were conducted to thoroughly discuss the effects of the impact displacement ratio, the FPB friction coefficient ratio, and the radius ratio on the structural dynamic response when considering impact and SSI. It was found that the pounding is extremely brief, with an exceptionally large pounding force generated by impact, resulting in significant acceleration pulse. The acceleration and inter-story shear force of the structure experiencing pounding were greater than those without considering pounding. Sudden changes in the inter-story shear force between the first and second floors of the structure were also observed. The dynamic response of structures in soft ground was significantly lower than that of structures in other ground conditions under the same conditions, regardless of the earthquake wave exciting the structure. When the structure is influenced by pulse-type earthquake records, its dynamic response exhibits a trend of first intensifying and then weakening as the equivalent radius ratio and friction coefficient ratio increase. However, it increases with an increase in the pounding displacement ratio, equivalent radius ratio, friction coefficient ratio, and displacement ratio when the structures are subjected to non-pulse-type seismic record.

• 한국재난정보학회 논문집
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• 제14권4호
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• pp.450-457
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• 2018

연구목적: 2016년 9월 경주 이후 구조물 및 비구조물의 지진 안전성 및 내진성능에 관한 문제가 이슈화 되고 있으며, 특히 배관 시스템의 경우 구조요소 보다 지진 발생시 내진성능에 있어서 취약하다고 볼 수 있다. 스프링클러 배관 시스템과 같은 비구조적 구성요소의 손상으로 인해 지진 발생 및 이후에 상당한 경제적 손실이나 생명 손실을 초래 할 수 있다. 연구방법: 본 연구는 Triple Friction Pendulum Bearings (TPBs)을 설치한 건물 배관 시스템을 이용한 소방 배관 시스템의 내진성능평가를 제시한다. Kobe, Kocaeli, GyeongJu 지진을 고려하여 지반 운동의 불확실성을 고려하였다. 연구결과: 빌딩 시스템과 파이핑 시스템의 첫 번째 모드는 각각 약 5.8Hz와 약 2.742Hz로 나타났으며, 또한 TPBs 시스템이 적용된 배관 시스템의 최대 변위는 Kobe, Kocaeli 및 GyeongJu 지진의 경우 각각 49%, 14.4%, 21.5%가 감소한 것으로 나타났다. 결론: 따라서 건물 배관 시스템에서 지진 격리 시스템을 사용하면 지진이 심할 때 TPB가 없는 일반적으로 설치된 걸물 배관 시스템보다 지진 위험을 줄일 수 있다.

• Structural Engineering and Mechanics
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• 제19권4호
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• pp.381-399
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• 2005

Base isolation technologies have been proven to be very efficient in protecting structures from seismic hazards during experimental and theoretical studies. In recent years, there have been more and more engineering applications using base isolators to upgrade the seismic resistibility of structures. Optimum design of the base isolator can lessen the undesirable seismic hazard with the most efficiency. Hence, tracing the nonlinear behavior of the base isolator with good accuracy is important in the engineering profession. In order to predict the nonlinear behavior of base isolated structures precisely, hundreds even thousands of degrees-of-freedom and iterative algorithm are required for nonlinear time history analysis. In view of this, a simple and feasible exact formulation without any iteration has been proposed in this study to calculate the seismic responses of structures with base isolators. Comparison between the experimental results from shaking table tests conducted at National Center for Research on Earthquake Engineering in Taiwan and the analytical results show that the proposed method can accurately simulate the seismic behavior of base isolated structures with elastomeric bearings. Furthermore, it is also shown that the proposed method can predict the nonlinear behavior of the VCFPS isolated structure with accuracy as compared to that from the nonlinear finite element program. Therefore, the proposed concept can be used as a simple and practical tool for engineering professions for designing the elastomeric bearing as well as sliding bearing.

• Structural Engineering and Mechanics
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• 제66권6호
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• pp.749-759
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• 2018

Aiming at widely used high-pier bridges in Sichuan-Tibet Railway, this paper presents an investigation to design and evaluate the seismic vibration reduction effects of several measures, including viscous damper (VD), friction pendulum bearing (FPB), and tuned mass damper (TMD). Primarily, according to the detailed introduction of the concerned bridge structure, dynamic models of high-pier bridges with different seismic vibration reduction (SVR) measures are established. Further, the designs for these SVR measures are performed, and the optimal parameters of these measures are investigated. On this basis, the vibration reduction effects of these measures are analyzed and assessed subject to actual earthquake excitations in Wenchuan Earthquake (M=8.0), and the most appropriate SVR measure for high-pier bridges in Sichuan-Tibet Railway is determined at the end of the work. Results show that the height of pier does not obviously affect the performances of the concerned SVR measures. Comprehensively considering the vibration absorption performance, installation and maintenance of all the employed measures in this paper, TMD is the best one to absorb vibrations induced by earthquakes.

• 한국소음진동공학회논문집
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• 제24권3호
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• pp.227-235
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• 2014

The demand of natural gas is gradually increasing as a clean fuel in the world. Therefore, LNG storage tanks and related facilities of the importance of leading a community-based facility have emerged. The seismic design of LNG storage tank including seismic analysis have been developed steadily. But, the seismic analysis and design techniques for LNG storage tanks are lacking, in Korea. Consequently, it is necessary to develop an analysis model that LNG storage tanks in isolation system can describe the behavior. Further, LNG storage tank capable of ensuring safety and economy, it is necessary to develop design techniques. The studies have suggested seismic design procedures of LNG storage tanks with isolation system including triple-FPB and idealized complex hysteresis model of triple-FPB.

• Smart Structures and Systems
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• 제22권4호
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• pp.383-397
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• 2018

Traditional base isolation systems focus on isolating the seismic response of a structure in the horizontal direction. However, in regions where the vertical earthquake excitation is significant (such as near-fault region), a traditional base-isolated building exhibits a significant vertical vibration. To eliminate this shortcoming, a rocking-isolated system named Telescopic Column (TC) is proposed in this paper. Detailed rocking and isolation mechanism of the TC system is presented. The seismic performance of the TC is compared with the traditional elastomeric bearing (EB) and friction pendulum (FP) base-isolated systems. A 4-storey reinforced concrete moment-resisting frame (RC-MRF) is selected as the reference superstructure. The seismic response of the reference superstructure in terms of column axial forces, base shears, floor accelerations, inter-storey drift ratios (IDR) and collapse margin ratios (CMRs) are evaluated using OpenSees. The results of the nonlinear dynamic analysis subjected to multi-directional earthquake excitations show that the superstructure equipped with the newly proposed TC is more resilient and exhibits a superior response with higher margin of safety against collapse when compared with the same superstructure with the traditional base-isolation (BI) system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.132-138
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• 2013

Natural gas as a clean fuel of the world demand for the trend is gradually increasing demand for clean energy in the country and there is growing interest. Therefore, LNG storage tanks and related facilities in the country of the importance of leading a community-based facility has emerged. So common sense that an earthquake with a seismic isolation device LNG storage tank similar to the actual behavior of the analytical model which can describe the development and construction of storage tanks to enhance the safety and economic design techniques need to be developed. In this study, a base isolation system, seismic analysis procedure of LNG storage tanks, and Triple-FPB developed a mathematical model of the present crystallized and complexity factors to the sum over histories model simplifies the complex behavior of the LNG storage tank with base isolation system how to interpret the seismic isolation is proposed.