테프론 또는 제강슬래그를 활용한 기초형 지진격리장치의 면진 메카니즘 평가

손수원,강인구,Pouyan Bagheri,김진만 한국지반공학회 2018 한국지반공학회논문집 Vol.34 No.1

In this study, seismic performance of geotechnical seismic isolation system capable of primary seismic isolation in the ground was evaluated. 1-G shaking table test was used to assess the performance of Teflon or steel slag as geotechnical seismic isolation systems installed beneath superstructure foundation. Response acceleration and response spectra were analyzed considering different input motions. The results were compared with those of fixed foundation structure without seismic isolation system. The steel slag-type seismic isolation system showed significant reduction in acceleration. The teflon-type seismic isolation system did not show significant effects on acceleration reduction in low-to-moderate seismicity condition, but it did show better effects in case of strong seismic condition. As input motion was transferred to the upper mass, the response spectrum of the fixed foundation structure was amplified in the short period range. In contrast, the response spectrum of the structure with seismic isolation using teflon or steel slag amplified in the long period range. It is found that the change of periodicity and the friction characteristics between isolation materials and foundations affected acceleration reduction.

면진장치 특성 변화에 따른 중간층 면진시스템의 지진응답 평가

김현수,김수근,강주원 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.1

As the number of high-rise buildings increases, a mid-story isolation system has been proposed for high-rise buildings. Due to structural problems, an appropriate isolation layer displacement is required for an isolation system. In this study, the mid-story isolation system was designed and the seismic response of the structure was investigated by varying the yield strength and the horizontal stiffness of the seismic isolation system. To do this, a model with an isolation layer at the bottom of 15th floor of a 20-story building was used as an example structure. Kobe(1995) and Nihonkai-Chubu(1983) earthquake are used as earthquake excitations. The yield strength and the horizontal stiffness of the seismic isolation system were varied to determine the seismic displacement and the story drift ratio of the structure. Based on the analytical results, as the yield strength and horizontal stiffness increase, the displacement of the isolation layer decreases. The story drift ratio decreases and then increases. The displacement of the isolation layer and the story drift ratio are inversely proportional. Increasing the displacement of the isolation layer to reduce the story drift ratio can cause the structure to become unstable. Therefore, an engineer should choose the appropriate yield strength and horizontal stiffness in consideration of the safety and efficiency of the structure when a mid-story isolation system for a high-rise building is designed.

하이브리드 중간층 지진격리시스템의 고층 건물 진동 제어 성능 평가

김현수,강주원 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.3

A base isolation system is widely used to reduce seismic responses of low-rise buildings. This system cannot be effectively applied to high-rise buildings because the initial stiffness of the high-rise building with the base isolation system maintains almost the same as the building without the base isolation system to set the yield shear force of the base isolation system larger than the design wind load. To solve this problem, the mid-story isolation system was proposed and applied to many buildings. The mid-story isolation system has two major objectives; first to reduce peak story drift and second to reduce peak drift of the isolation story. Usually, these two objectives are in conflict. In this study, a hybrid mid-story isolation system for a tall building is proposed. A MR (magnetorheological) damper was used to develop the hybrid mid-story isolation system. An existing building with mid-story isolation system, that is “Shiodome Sumitomo Building” a high rise building having a large atrium in the lower levels, was used for control performance evaluation of the hybrid mid-story isolation system. Fuzzy logic controller and genetic algorithm were used to develop the control algorithm for the hybrid mid-story isolation system. It can be seen from analytical results that the hybrid mid-story isolation system can provide better control performance than the ordinary mid-story isolation system and the design process developed in this study is useful for preliminary design of the hybrid mid-story isolation system for a tall building.

하이브리드 중간층 지진 격리 시스템과 빌딩 구조물의 동시 최적화

강주원,김현수 한국공간구조학회 2019 한국공간구조학회지 Vol.19 No.3

A hybrid mid-story seismic isolation system with a smart damper has been proposed to mitigate seismic responses of tall buildings. Based on previous research, a hybrid mid-story seismic isolation system can provide effective control performance for reduction of seismic responses of tall buildings. Structural design of the hybrid mid-story seismic isolation system is generally performed after completion of structural design of a building structure. This design concept is called as an iterative design which is a general design process for structures and control devices. In the iterative design process, optimal design solution for the structure and control system is changed at each design stage. To solve this problem, the integrated optimal design method for the hybrid mid-story seismic isolation system and building structure was proposed in this study. An existing building with mid-story isolation system, i.e. Shiodome Sumitomo Building, was selected as an example structure for more realistic study. The hybrid mid-story isolation system in this study was composed of MR (magnetorheological) dampers. The stiffnessess and damping coefficients of the example building, maximum capacity of MR damper, and stiffness of isolation bearing were simultaneously optimized. Multi-objective genetic optimization method was employed for the simultaneous optimization of the example structure and the mid-story seismic isolation system. The optimization results show that the simultaneous optimization method can provide better control performance than the passive mid-story isolation system with reduction of structural materials.

면진장치의 적용 유무에 따른 구조물의 동적특성 파악을 위한 진동대 실험계획

송성훈,유홍식,오상훈,이상호 대한건축학회지회연합회 2008 대한건축학회지회연합회 학술발표대회논문집 Vol.2008 No.1

This research is to develop more effective seismic isolation system and to standardize a design processor for a seismic isolation structure system based on energy method by applying a isolation damper using HTS(High Toughness Steel which has been being studied) to the seismic isolation system. This research is conducted in four different stages. First, design two types of specimen for a shaking table test. One is not applied a seismic isolation system, the other is applied a seismic isolation system. Second, expect the dynamic characteristics of each specimen through analytical study using computer program Midas Gen ver.741. Third, compare analytical result with experimental result which will be obtained from a shaking table test next time. Lastly, suggest a design processor for a seismic isolation structure system based on energy method. In this study, our efforts especially focused on the first and second stage.

면진 원전 면진-비면진구간 연결 배관의 내진성능 평가

함대기,박준희,최인길 한국지진공학회 2014 한국지진공학회논문집 Vol.18 No.3

A methodology to evaluate the seismic performance of interface piping systems that cross the isolation interface in the seismically isolated nuclear power plant (NPP) was developed. The developed methodology was applied to the safety-related interface piping system to demonstrate the seismic performance of the target piping system. Not only the seismic performance for the design level earthquakes but also the performance for the beyond design level earthquakes were evaluated. Two artificial seismic ground input motions which were matched to the design response spectra and two historical earthquake ground motions were used for the seismic analysis of piping system. The preliminary performance evaluation results show that the excessive relative displacements can occur in the seismically isolated piping system. If the input ground motion contained relatively high energy in the low frequency region, we could find that the stress response of the piping system exceed the allowable stress level even though the intensity of the input ground motion is equal to the design level earthquake. The structural responses and seismic performances of piping system were varied sensitively with respect to the intensities and frequency contents of input ground motions. Therefore, for the application of isolation system to NPPs and the verification of the safety of piping system, the seismic performance of the piping system subjected to the earthquake at the target NPP site should be evaluated firstly.

제강슬래그 기초지진격리장치의 지진하중 저감효과

손수원,전홍우,류정호,김진만 한국방재학회 2014 한국방재학회논문집 Vol.14 No.1

Seismic isolation systems including Laminated Rubber Bearing(LRB) and Friction Pendulum System(FPS) have been being used toimprove the seismic performance of bridge structures. This paper studied the seismic load reduction effect of a steel slag-based seismicfoundation isolation system by using 1-G shaking table tests. The result shows that ground acceleration reduces significantlythrough soft clay ground to the foundation isolation system, and it further reduces through the foundation isolation system. Numericalanalyses show similar results. These results show that the seismic foundation isolation system is effective in seismic performanceimprovement of bridge structure. 교량 구조물의 내진성능을 향상하기 위해 Laminated Rubber Bearing(LSB)과 Friction Pendulum System(FPS) 등의 다양한 종류의지진격리장치가 사용되고 있다. 본 연구에서는 LSB와 FPS와 달리 설치비용과 운반비용을 절약할 수 있는 제강 슬래그를 이용한기초지진격리장치를 연구하였으며, 1-G 진동대 시험을 이용하여 기초지진격리장치의 지진하중저감효과를 분석하였다. 연구결과,기반암에서 기초지진격리장치까지 도달하는 동안 연약점토지반에서 상당한 진동 감소가 발생했으며, 기초지진격리장치를 통과하면서 가속도가 추가로 감소되는 효과를 보였다. 진동대 실험과 함께 수행된 수치해석은 실험과 유사한 결과를 나타냈다. 이러한 결과는 기초지진격리장치가 교량구조물의 내진성능을 개선하는 효과가 있다는 것을 보여준다.

고층 건물에 적용한 면진 시스템의 설치 위치에 따른 지진 응답 분석

김민주,김동욱,김현수,강주원 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.4

Seismic isolation systems have typically been used in the form of base seams in mid-rise and low-rise buildings. In the case of high-rise buildings, it is difficult to apply the base isolation. In this study, the seismic response was analyzed by changing the installation position of the seismic isolation device in 3D high - rise model. To do this, we used 30-story and 40-story 3D buildings as example structures. Historic earthquakes such as Mexico (1985), Northridge (1994) and Rome Frieta (1989) were applied as earthquake loads. The installation position of the isolation device was changed from floor to floor to floor. The maximum deformation of the seismic isolation system was analyzed and the maximum interlaminar strain and maximum absolute acceleration were analyzed by comparing the LB model with seismic isolation device and the Fixed model, which is the base model without seismic isolation device. If an isolation device is installed on the lower layer, it is most effective in response reduction, but since the structure may become unstable, it is effective to apply it to an effective high-level part. Therefore, engineers must consider both structural efficiency and safety when designing a mid-level isolation system for high-rise buildings.

중간층 면진시스템 설치 위치에 따른 고층건물의 지진응답 분석

김가영,이영락,김현수,강주원 한국공간구조학회 2017 한국공간구조학회지 Vol.17 No.4

Base isolation system is generally used for low-rise buildings. For high-rise buildings subjected to earthquake loads, a mid-story isolation system was proposed and applied to practical engineering. In this study, seismic responses of high-rise buildings considering the installation story of the mid-story isolation system were evaluated. To do this, the 20-story and 30-story building were used as example structures. Historical earthquakes such as Kobe (1995), Northridge (1994) and Loma Prieta (1989) earthquakes were employed applied as earthquake excitations. The installation location of the mid-story isolation system was changed from the bottom of the 1st floor to the bottom of the top floor. The seismic responses of the example building were investigated by changing the location of the isolation layer. Based on the analytical results, when the seismic isolation system is applied, story drift ratio and acceleration response are reduced compared to the case without the isolation system. When the isolation layer is located on the lower part of the building, it is most effective. However, in that case, the possibility that the structure is unstable increases. Therefore, an engineer should consider both structural efficiency and safety when a mid-story isolation system for a high-rise building is designed.

평면 비정형 구조물에 적용된 중간층 면진 시스템의 지진 응답 제어 성능 분석

박효선,김현수,강주원,Park, Hyo-Sun,Kim, Hyun-Su,Kang, Joo-Won 한국공간구조학회 2019 한국공간구조학회지 Vol.19 No.2

In this study, the seismic response is investigated by using a relatively low-rise building under torsion-prone conditions and three seismic loads with change of the location of the seismic isolation system. LRB (Lead Rubber Bearing) was used for the seismic isolator applied to the analytical model. Fixed model without seismic isolation system was set as a basic model and LB models using seismic isolation system were compared. The maximum story drift ratio and the maximum torsional angle were evaluated by using the position of the seismic layer as a variable. It was confirmed that the isolation device is effective for torsional control of planar irregular structures. Also, it was shown that the applicability of the mid-story seismic isolation system. Numerical analyses results presented that an isolator installed in the lower layer provided good control performance for the maximum story drift ratio and the maximum torsional angle simultaneously.