2016년 경주지진(규모 5.8) 및 2017년 포항지진(규모 5.4)은 1978년 대한민국 지진 관측 이래 국내 에서 발생한 지진 중 가장 큰 피해가 발생한 지진으로 기록되었다. 지진의 피해사례는 다양한 분야에 서 발생되었으며, 그중 교량 구조물에도 부분적인 피해가 다수 발생하였다. 국내에서는 교량구조물에 대한 내진보강 사업을 지속적으로 진행하고 있으며, 내진 보강의 공법 중 면진받침을 적용하여 구조물 의 내진성능을 확보하는 사례는 지속적으로 증가하고 있는 추세이다. 펜들럼 교량받침은 중간판의 기 하학적인 곡률과 고강도 마찰재를 이용하여 감쇠 기능뿐 아니라 복원 기능을 구비하고 있는 면진받침 으로써 제품 크기가 작아 시공성, 경제성이 우수하여 국내에서 가장 많이 사용되고 있는 대표적인 면 진장치이다. 펜들럼 받침의 경우 지진력 감쇠 및 회전, 이동량 수용을 위하여 2면의 곡면 구조로 진자 운동을 하므로 수평 변위 발생 시 필수적으로 수직 단차가 발생하는 구조이다. 또한 면압에 따라 마찰 계수가 달라지는 마찰재의 특성을 고려한 특성치 산출이 필요한 제품이다. 이 연구에서는 펜들럼 받침 의 다양한 면압에 따른 동적 시험을 실시하여 실제 거동과 일치하는 설계 특성치 산출법을 정립하였 다. 또한 펜들럼 면진받침의 진자 운동을 반영한 모양의 가이드와 프리세팅 전, 후에도 받침 상판의 수평을 유지할 수 있는 장치를 실물 크기로 제작하여 공인기관에 의뢰하여 프리세팅 시험 및 완제품 성능 시험을 실시하여 그 성능을 검증하였다. 성능 시험 결과 곡률에 따른 프리세팅이 가능함을 확인 하였다. 또한, 곡률형 프리세팅을 적용한 펜들럼 면진받침이 구조적으로 안전함을 확인하였다.

A mid-story isolation system was proposed for seismic response reduction of high-rise buildings and presented good control performance. Control performance of a mid-story isolation system was enhanced by introducing semi-active control devices into isolation systems. Seismic response reduction capacity of a semi-active mid-story isolation system mainly depends on effect of control algorithm. AI(Artificial Intelligence)-based control algorithm was developed for control of a semi-active mid-story isolation system in this study. For this research, an practical structure of Shiodome Sumitomo building in Japan which has a mid-story isolation system was used as an example structure. An MR (magnetorheological) damper was used to make a semi-active mid-story isolation system in example model. In numerical simulation, seismic response prediction model was generated by one of supervised learning model, i.e. an RNN (Recurrent Neural Network). Deep Q-network (DQN) out of reinforcement learning algorithms was employed to develop control algorithm The numerical simulation results presented that the DQN algorithm can effectively control a semi-active mid-story isolation system resulting in successful reduction of seismic responses.

Spatial structure does not have columns and walls installed inside, so they have a large space. There are upper structure and substructure supporting them. The response of seismic loads to the upper structure may be increased or decreased due to the effects of the substructure. Therefore, in this study, the seismic response of the upper structure and the floor response spectrum of the substructure were compared and analyzed according to the height of the substructure in the spatial structure where the LRB was installed. As a result, the possibility of amplification of response was confirmed as seismic waves passed though the substructure, which is likely to increase the response of the upper structures.

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.

A seismic isolation system is one of the most effective control devices used for mitigating the structural responses due to earthquake loads. This system is generally used as a type of base isolation system for low- and mid-rise building structures. If the base isolation technique is applied to high-rise buildings, a lot of problems may be induced such as the movement of isolation bearings during severe wind loads, the stability problem of bearings under large compression forces. Therefore, a mid-story isolation system was proposed for seismic protection of high-rise buildings. Residence-commerce complex buildings in Korea have vertical irregularity because shear wall type and frame type structures are vertically connected. This problem can be also solved by the mid-story isolation system. An effective analytical method using super elements and substructures was proposed in this study. This method was used to investigate control performance of mid-story isolation system for residence-commerce complex buildings subjected to seismic loads. Based on numerical analyses, it was shown that the mid-story isolation system can effectively reduce seismic responses of residence-commerce complex tall buildings.

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 midstory 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.

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.

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.

The objective of this study is to investigate the response reducing effect of a seismic isolation system installed between 300m dome and supports under both horizontal and vertical seismic ground motion. The time history analysis is performed to investigate the dynamic behavior of single layer lattice domes with and without a lead rubber bearing seismic isolation system. In order to ensure the seismic performance of lattice domes against strong earthquakes, it is important to investigate the mechanical characteristics of dynamic response. Horizontal and vertical seismic ground motions cause a large asymmetric vertical response of large span domes. One of the most effective methods to reduce the dynamic response is to install a seismic isolation system for observing seismic ground motion at the base of the dome. This paper discusses the dynamic response characteristics of 300m single layer lattice domes supported on a lead rubber seismic isolation device under horizontal and vertical seismic ground motions.

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.

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.

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.

Various seismic isolation methods are being applied to bridges and buildings to improve their seismic performance. Most seismic isolation systems are the structural seismic isolation systems. In this study, the seismic performance of geotechnical seismic isolation system capable of isolating the lower foundation of the bridge structure from ground was evaluated. The geotechnical seismic isolation system was built with teflon, and the model structure was made by adopting the similitude law. The response acceleration for sinusoidal waves of various amplitudes and frequencies and seismic waves were analyzed by performing 1-G shaking table experiments. Fixed foundation, Sliding foundation, and Rocking foundation were evaluated. The results of this study indicated that the Teflon-type seismic foundation isolation system is effective in reducing the acceleration transmitted to the superstructure subject to large input ground motion. Response spectrum of the Rocking and Sliding foundation structures moves to the long period, while that of Fixed foundation moves to short period.

The seismic isolation system reduces the seismic vibration that is transmitted from foundation to upper structure. This seismic isolation system can be classified into base isolation and mid-story isolation by the installation location. In this study, the seismic behavior of dome structure with mid-story isolation is analyzed to verify the effect of seismic isolation. Mid-story isolation is more effective than base isolation to reduce the seismic responses of roof structure. Also, this isolation would be excellent in structural characteristics and construction.

Copper (Cu) is a necessary microelement for plants. However, high concentrations of Cu are toxic to plants that change the regulation of several stress-induced proteins. In this study, an annealing control primer (ACP) based approach was used to identify differentially expressed Cu-induced genes in alfalfa leaves. Two-week-old alfalfa plants (Medicago sativa L.) were exposed to Cu for 6 h. Total RNAs were isolated from treated and control leaves followed by ACP-based PCR technique. Using GeneFishing ACPs, we obtained several genes those expression levels were induced by Cu. Finally, we identified several genes including UDP-glucuronic acid decarboxylase, transmembrane protein, small heat shock protein, C-type cytochrome biogenesis protein, mitochondrial 2-oxoglutarate, and trans-2,3-enoyl-CoA reductase in alfalfa leaves. These identified genes have putative functions in cellular processes such as cell wall structural rearrangements, transduction, stress tolerance, heme transport, carbon and nitrogen assimilation, and lipid biosynthesis. Response of Cu-induced genes and their identification in alfalfa would be useful for molecular breeding to improve alfalfa with tolerance to heavy metals.

ASCE 4 requires that a hard stop be built around the seismic isolation system in nuclear power plants. In order to maintain the function of the isolation system, this hard stop is required to have clearance-to-stop, which should be no less than the 90th-percentile displacements for 150% Design Basis Earthquake (DBE) shaking. Huang et al. calculated clearance-to-stop by using a Latin Hypercube Sampling technique, without considering the rocking behavior of the isolated structure. This paper investigates the effects on estimation of clearance-to-stop due to 1) rocking behavior of the isolated structure and 2) sampling technique for considering the uncertainties of isolation system. This paper explains the simplified analysis model to consider the rocking behavior of the isolated structure, and the input earthquakes recorded at Diablo Canyon in the western United States. In order to more accurately approximate the distribution tail of the horizontal displacement in the isolated structure, a modified Latin Hypercube Sampling technique is proposed, and then this technique was applied to consider the uncertainty of the isolation system. Through the use of this technique, it was found that rocking behavior has no significant effect on horizontal displacement (and thus clearance-to-stop) of the isolated structure, and the modified Latin Hypercube Sampling technique more accurately approximates the distribution tail of the horizontal displacement than the existing Latin Hypercube Sampling technique.

본 연구에서는 고정기초, 기초면진, 및 최상층에 TMD가 설치된 기초면진 구조물에 풍하중이 작용하는 경우에 구조물의 동적 거동을 해석하는 프로그램을 개발하여 면진장치가 풍하중이 작용하는 구조물의 동적거동에 미치는 영향을 파악하고자 한다. 난기류 스펙트럼을 이용하여 구조물에 작용하는 바람을 실제와 유사하도록 생성한 풍하중을 해석에 적용한다. 기초면진 장치가 구조물의 동적 거동에 미치는 영향을 분석하고, 풍하중이 작용하는 경우 기초면진이 설치된 구조물에서 TMD의 동적 제어 효과에 대하여 분석하고자 한다.