In this study, the performance evaluation of steel dampers was conducted based on existing research results. The test variables are cross-sectional shape and lateral deformation prevention details. As a result of performance tests according to cross-sectional shape, the circular cross-section was evaluated to be superior than the rectangular cross-section in terms of envelope, stiffness reduction, and energy dissipation capacity. In addition, it was evaluated that the rectangular cross-section where lateral deformation occurs can be restrained by lateral deformation prevention details, thereby improving strength and deformation capacity.

This study investigated the rocking behavior of unreinforced masonry walls and wall piers under cyclic loading. Based on the benchmark tests, the characteristics of load-deformation relations in masonry walls with rocking failure were captured, focusing on observed deformation modes. The rocking strengths of masonry walls (i.e., peak and residual strengths) were evaluated, and the effects of opening configurations on the masonry wall strength were examined. The deformation capacity of the rocking behavior and the hysteresis shape of the load-deformation relations were also identified. Based on the results, modeling approaches for the rocking behavior of masonry walls were discussed.

In this study, performance experiments were performed on the shape of steel dampers that affect the rocking behavior. Three types of strut shapes of SI type, SV type and SS type were considered as experimental variables. As a result of the experiment, the capacity to resist the moment and drift ratio according to the strut shape of the steel damper was evaluated as very close. Finally, it was evaluated that the SV type steel damper has stable deformation and energy dissipation capability. As a result of the evaluation of the proposed damper transmission force, it is considered that the damper transmission force is evaluated larger than the applied horizontal force, and it is necessary to supplement it.

Electrical instruments and devices contained in cabinets for controlling nuclear power plants require seismic qualification; likewise, in-cabinet response spectrum (ICRS) is necessary. Gupta et al. (1999) suggested the Ritz method, where rocking, frame bending, and plate bending behaviors of cabinets are considered, as a method for determining ICRS. This research proposes a method to determine the rocking stiffness of cabinets, which represents its rocking behavior. The cabinet is fixed on mounting frames and is connected to the base concrete by anchors. When horizontal excitation is applied to the cabinet, the mounting frames at anchors are locally deformed, the mounting frames are bent, and then rocking in the cabinet becomes evident. A method to determine equivalent vertical spring stiffness representing the local deformation of the mounting frames at anchors is then proposed. Subsequently, the rocking stiffness of this mounting frame is calculated upon assumption of the mounting frame as an indeterminate beam.

This study proposes a technique to dissipate the energy of a rocking wall installed on a frame by using a metallic damper. The rocking behavior is to turn left and right about the wall vertical axis. The development system is a method of dissipating energy by installing a damper which is the like on a large displacement portion. Experimental results showed that in case of shorter strut make strength capacity increasement and in case of longer strut make deformation capacity increasement. The higher the strut height, the better the energy dissipation capacity. The proposed equation for estimating the steel damper strength applied to this study is a straight type strut damper. However, it is not suitable for calculation of the strength of clamped type strut damper where both flexural behavior and shear behavior are mixed.

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.

연약한 지반위에 기초한 유연한 구형 액체 저장탱크의 Rocking 운동에 대한 3차원 지진응답을 규명하기 위해서 동적 유체-구조 물-지반 계의 상호작용 해석방법을 개발하였다. 수평방향 병진 운동과 Rocking 운동을 받는 3차원의 구형 탱크의 운동 지배방정식을 Rayleigh-Ritz 방법을 적용하여 유도하였고 기반암위 토층의 표면에 놓인 강체 기초의 동적 강성행렬과 유체-구조물 계의 지배방정식을 결합하여 계산하였다.

록킹 거동은 구조체가 수평력을 받을 때, 수직 중심을 기준으로 좌우로 회전하는 거동을 의미한다. 본 연구에서는 최신의 연구 동향을 개념으로 하여 강체 좌우에 댐퍼를 설치하여 에너지를 소산시키는 방법을 고안하였다. 강재 댐퍼는 SS275 강종을 사용하였으며, 두께 12mm, 폭 30mm, 높이 140mm인 S형 스트럿을 가지는 형상을 사용하였다. 실험은 변위를 점진적으로 증가시키면서 진행하였다. 향후 댐퍼 스트럿 형상 및 스트럿 높이를 변수로 한 성능실험 결과를 발표할 예정이다.

본 연구에서는 벽체의 록킹 거동을 고려한 내진보강 기법을 개발하였다. 록킹 거동은 벽체 수직 축을 중심으로 좌우로 회전하는 것으로, 개발 시스템은 변위 큰 부분에 댐퍼 등을 설치하여 에너지를 소산 시키는 방법이다. 댐퍼는 강재댐퍼를 사용하였으며, 스트럿 형상 및 높이를 변수로 선정하였다. 실험결과 스트럿 높이가 짧을수록 강도 능력이, 길수록 변형능력이 우수한 것으로 평가되었다. I형과 S형 스트럿 능력을 평가한 결과, S형이 우수한 내진 성능을 보유한 것으로 평가되었다.

The seismic performance evaluation for the electrical cabinets is conducted by the shaking table test or numerical analysis. When performing the seismic evaluation by the numerical analysis, it usually assumes that the electrical cabinets are rigidly anchored to the floor. This assumption may not be valid depending on how the cabinets are anchored. In particular, if a cabinet is anchored with bolts, a local plastic deformation of the base plate of the cabinet may cause rocking. Therefore, in this study, the shaking table test was performed to analyze the rocking effect of the electrical cabinet in an experimental method.

In this study, as a part of the BCP (Business Continuous Plan), the performance tests of the rocking wall and the steel damper were carried out. The rocking wall was made of concrete block. The concrete block was connected to the floor by two hinges. However, in the performance test, the hinge part was destroyed and the experiment was finished. This will be due to the fact that the hinge has not rotated, and will be retested after reinforcement of the concrete block.

In this study, seismic strengthening method using precast concrete rocking wall is considered in the literature studies. As a result of reviewing the two studies, it is considered necessary to develop a sequential study on development of lightweight precast wall panel, application of post-tension method, and development of location and shape of energy dissipation devices.