Development of Three Dimensional Seismic Isolation Device With Laminated Rubber Bearing and Rolling Seal Type Air Spring

2002 ◽  
Author(s):  
Junji Suhara ◽  
Tadashi Tamura ◽  
Yasuo Okada ◽  
Katsuhiko Umeki
Keyword(s):  
Seismic Isolation ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Horizontal Load ◽  
3D Seismic ◽  
Air Spring ◽  
Ability Test ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing ◽  
Isolation Device

Three dimensional (3D) seismic isolation device has been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed device is the 3D seismic isolation device that consists of the laminated rubber bearing as a horizontal isolation device and the rolling seal type air spring as the vertical isolation device in series. In this research, the 3D seismic isolation device reduction model whose scale is 1/10 is made and the workability of the device by the horizontal and vertical dynamic load is examined. Two experiment parameters are considered. One is the case that the structure of the part that the horizontal load and the vertical load contact is pin condition and the other is the case of the roller condition. As a result of the examination, the workability of the vertical direction is confirmed when the horizontal load acts. The pressure resistant ability test for the air spring is performed by the monotonic pressurization. As the result, it is confirmed that pressure resistant ability improved by restricting the side deformation of the air spring and that the material of the existing air spring can withstand high pressure use sufficiently. As the result, it is confirmed that the developed 3D seismic isolation device is applicable to the actual plant.

Three-Dimensional Seismic Isolation Device With Rolling Seal Type Air Spring

2004 ◽  
Author(s):  
Tetsuya Hagiwara ◽  
Junji Suhara ◽  
Satoshi Moro
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
3D Seismic ◽  
Air Spring ◽  
Scaled Model ◽  
Isolation System ◽  
Ability Test ◽  
Rubber Bearing ◽  
Isolation Device

Three dimensional (3D) seismic isolation device has been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed device is the 3D seismic isolation device that consists of the laminated rubber bearing as a horizontal isolation device and the rolling seal type air spring as the vertical isolation device in series. As the lead rubber bearing and the air spring are individually widely utilized with the general buildings and industrial structures, their reliability is high. However, when these pieces of equipment are combined, the issues that should be developed arise. The prospect of the technical feasibility of the device has already been acquired by feasibility test. In this study, a 1/12-scaled model of a 3D base isolation device is manufactured and the four tests are carried out. The four tests are dynamic vertical and horizontal test, orifice-damping test, pressure resistant ability test, and accelerated aging test. As the results of the tests, the developed 3D seismic isolation device is confirmed to be applicable to a nuclear power plant.

Three Dimensional Seismic Isolation System Using Hydraulic Cylinder

2002 ◽  
Author(s):  
Shinichiro Kajii ◽  
Naoki Sawa ◽  
Nobuhiro Kunitake ◽  
K. Umeki
Keyword(s):  
Seismic Isolation ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Hydraulic Cylinder ◽  
Seismic Load ◽  
3D Seismic ◽  
Isolation System ◽  
Response Characteristics ◽  
Seismic Motion ◽  
Hydraulic Cylinders

A three-dimensional (3D) seismic isolation system for FBR building is under development. The proposed vertical isolation system consists form hydraulic cylinders with water-based liquid and accumulators to support large vertical static load and to realize low natural frequency in the vertical direction. For horizontal isolation, laminated rubber isolator or sliding type isolator will be combined. Because the major part of the feasibility of this isolation system depends on the sealing function and durability of the hydraulic cylinder, a series of feasibility tests of the hydraulic cylinder have been conducted to verify the reliability against seismic load and seismic motion. This paper describes the specification of the seismic isolations system, seismic response characteristics and the results of the feasibility tests of the seal. This study was performed as part of a government sponsored R&D project on 3D seismic isolation.

Analysis of Vibration Isolator’s Anti-Seismic Performance in Porcelain SF6 High Voltage Circuit Breaker

2013 ◽  
Vol 448-453 ◽  
pp. 2045-2048
Author(s):  
Yan Zhong Ju ◽  
Xin Lei Wu
Keyword(s):  
Seismic Performance ◽  
High Voltage ◽  
Seismic Isolation ◽  
Circuit Breaker ◽  
Isolation System ◽  
High Voltage Circuit Breaker ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing ◽  
Sf6 Circuit Breaker ◽  
Isolation Device

Choosing LW15-550Y porcelain high voltage SF6 circuit breaker as the research subject, we designed the lead laminated rubber bearing (LRB) seismic isolation device for LW15-550Y circuit breaker. We finally gets the results that the LRB isolation system increases the flexibility of the breaker structure and improves the seismic performance of the high voltage circuit breaker structure.

Development of Three-Dimensional Seismic Isolation Technology for Next Generation Nuclear Power Plant in Japan

2004 ◽  
Author(s):  
K. Inoue ◽  
M. Morishita ◽  
T. Fujita
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
3D Seismic ◽  
Next Generation ◽  
Air Spring ◽  
Isolation System ◽  
Earthquake Loads ◽  
Base Isolation System

Mitigation of earthquake loads by seismic isolation technology is very promising for enhanced safety and economy of the next generation nuclear reactors, through rationalized and simplified design of structures, systems and components. The horizontal base isolation with laminated rubber bearings is a proven technology and its application has been widely spread including nuclear facilities. On the other hand, significantly increased benefit of mitigated seismic loads is expected with three-dimensional (abbreviated 3D) seismic isolation, since the earthquake loads are inherently three-dimensional and the vertical component of the earthquake load sometimes plays an important role in the structural design of reactor components. From these points of view, a research project has been undertaken for the development of 3D seismic isolation technology, under the sponsorship of the Ministry of Economy, Trade and Industry of the Japanese government. It was presented in a former conference that two types of 3D seismic isolation systems were applicable to the next generation nuclear power plants. One is 3D base isolation of a whole nuclear island, and the other is a vertical isolation system for main components with horizontal base isolation system. Among a number of proposed concepts, three were promising ideas for the 3D base isolation system (or device), i.e., “hydraulic 3D base isolation system”, “independent cable reinforced rolling-seal air spring”, and “rolling seal type air spring”. Then the last idea, i.e., “rolling seal type air spring”, was selected from above three ideas for further development. In this paper, current status of this R&D project are firstly shown. Next, the performance requirements for 3D isolation system and devices are shown. Then the developing targets for 3D isolation technology are shown. Furthermore, future plan of the project is provided.

Study on Three-Dimensional Seismic Isolation System for Next Generation Nuclear Power Plant: Independent Cable Reinforced Rolling-Seal Air Spring

2004 ◽  
Author(s):  
Mitsuru Kageyama ◽  
Yoshihiko Hino ◽  
Satoshi Moro
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Outer Diameter ◽  
Next Generation ◽  
Air Spring ◽  
Isolation System ◽  
Rubber Sheet

In Japan, the development of the next generation NPP has been conducted in recent years. In the equipment/piping design of the plant, seismic condition has been required much more mitigate than before. So, the three-dimensional (abbreviation to 3D) seismic isolation system development has also been conducted since 2000. The superlative 3D base isolation system for the entire building was proposed. The system is composed of cable reinforced air springs, rocking arresters and viscous dampers. Dimensions of the air spring applied to the actual power plant are 8 meters in the outer-diameter and 3.5 meters in height. The allowable half strokes are 1.0 meters in horizontal and 0.5 meters in vertical respectively. The maximum supporting weight for a single device is 70 MN. The inner design air pressure is about 1.8MPa. This air spring has a distinguishing feature, which realizes 3D base isolation with a single device, whose natural periods are about 4 seconds in horizontal and about 3 seconds in vertical. In order to verify the 3D performance of this system, several feasibility tests were conducted. Firstly, 3D shaking table tests were conducted. The test specimen is scaled 1/4 of the actual device. The outer diameter and inner air pressure of air spring is 2 meters and 0.164 MPa. Next, a pressure resistant test for the sub cable, textile sheet and rubber sheet, which composed air spring, were conducted as a full scale model test. Then, air permeation test for the rubber sheet was also conducted. As a result, the proposed system was verified that it could be applied to the actual nuclear power plants.

Three Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant With Rolling Seal Type Air Spring and Hydraulic Rocking Suppression System

2005 ◽  
Author(s):  
Takahiro Shimada ◽  
Junji Suhara ◽  
Kazuhiko Inoue
Keyword(s):  
Dynamic Loading ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Loading Test ◽  
Isolation System ◽  
Ability Test ◽  
Base Isolation System ◽  
Suppression System

Three dimensional (3D) seismic isolation devices have been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed seismic isolation system is composed of rolling seal type air springs and the hydraulic type springs with rocking suppression system for vertical base isolation device. In horizontal direction, the same laminated rubber bearings are used as horizontal isolation device for these systems. The performances and the applicability have already been evaluated by the technical feasibility tests and performance tests for each system. In this study, it was evaluated that the performance of the 3D base isolation system with rolling seal type air springs combined with hydraulic rocking suppression devices. A 1/7 scaled model of the 3D base isolation devices were manufactured and some performance test were executed for each device. For the rolling seal type air springs, dynamic loading test was executed with a vibration table, and pressure resistant ability test was executed for reinforced air springs. In the dynamic loading test, it is confirmed that the natural period and damping performance were verified. In the pressure resistant ability test, it is confirmed that the air springs had sufficient strength. For the hydraulic rocking suppression system, forced dynamic loading test was carried out in order to measure the frictional and oil flow resistance force on each cylinder. And the vibration table tests were carried out with supported weight of 228 MN in order to evaluate and to confirm the horizontal and vertical isolation performance, rocking suppression performance, and the applicability of the this seismic isolation system as the combined system. 4 rolling seal type air springs and 4 hydraulic load-carrying cylinders with rocking suppression devices supported the weight. As a result, the proposed system was verified that it could be applied to the actual nuclear power plant building to be target.

scholarly journals Laminated Rubber Bearing for Seismic Isolation

Kobunshi ◽  
2008 ◽  
Vol 57 (7) ◽  
pp. 523-523 ◽  
Author(s):  
Toshikazu YOSHIZAWA
Keyword(s):  
Seismic Isolation ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing

Development of Cable Reinforced 3-Dimensional Base Isolation Air Spring

2002 ◽  
Author(s):  
Mitsuru Kageyama ◽  
Tsutomu Iba ◽  
Takahiro Somaki ◽  
Hisako Hino ◽  
Katsuhiko Umeki
Keyword(s):  
Power Plant ◽  
Base Isolation ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Air Pressure ◽  
Horizontal Direction ◽  
Outer Diameter ◽  
Air Spring ◽  
Steel Cable ◽  
3 Dimensional

In Japan, the study on the development of a 3-dimensional base isolation system to be applied to a nuclear power plant, which requires supreme safety against severe earthquakes, has been carried out since 2000. An idea with the concept of a cable reinforced air spring was proposed as the 3-dimensional base isolation device. The dimension of the air spring applying to the actual power plant is 9 meters in the outer-diameter and 3.5 meters in height. The allowable half strokes are respectively 1.5 meters for the horizontal direction and 0.5 meters for the vertical directions. The supporting weight for a single device is 52MN, where the inner air pressure is about 1.2MPa. This device enables to realize three-dimensional base isolation with a single device, whose characteristics is a natural period of over 4 seconds in the horizontal direction and over 3 seconds in the vertical direction. Furthermore, this device does not require precision mechanical parts just common building materials, which are steel, cable wire, polyester fabric and a rubber sheet. Therefore, the construction cost for this device could be reduced effectively. In order to confirm the performance of the proposed device, experimental tests using the three dimensional shaking table were carried out on the proposed cable reinforced 3-dimensional base isolation air spring, whose outer diameter is 2 meters, being 1/4.5 scale of the actual size. The weight of approximately 392kN including a 4-story steel frame was loaded on the test specimen in order to create inner air pressure of 0.157MPa. As a result, the device was confirmed to function smoothly in three dimensions with natural periods of 1.8 seconds in the horizontal direction and 1.4 seconds in the vertical direction, and is considered that the proposed system can be applied to actual power plants.

scholarly journals Vertical Seismic Isolation Device for Three-Dimensional Seismic Isolation of Nuclear Power Plant Equipment—Case Study

2021 ◽  
Vol 12 (1) ◽  
pp. 320
Author(s):  
Gyeong-Hoi Koo ◽  
Jin-Young Jung ◽  
Jong-Keun Hwang ◽  
Tae-Myung Shin ◽  
Min-Seok Lee
Keyword(s):  
Energy Dissipation ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Three Dimensional ◽  
Seismic Energy ◽  
Vertical Load ◽  
Power Plant Equipment ◽  
Plant Equipment ◽  
Steel Damper ◽  
Isolation Device

The purpose of this study was to develop a vertical seismic isolation device essential for the three-dimensional seismic isolation design of nuclear power plant equipment. The vertical seismic isolation device in this study has a concept that can be integrally combined with a conventional laminated rubber bearing, a horizontal seismic isolator with a design vertical load of 10 kN. To develop the vertical seismic isolation device, the vertical spring and the seismic energy dissipation device capable of limiting the vertical displacement of the spring were designed and their performances were verified through actual tests. In this study, the target elevation of the floor is 136 ft, where safety-related nuclear equipment, such as cabinet and remote shutdown console, etc., is installed. The sensitivity studies were carried out to investigate the optimal design vertical isolation frequencies for the target building elevation. Based on the results of the sensitivity study, a disc spring and a helical coil spring were selected for the vertical stiffness design, and the steel damper was selected for the seismic energy dissipation, and their performance characteristics were tested to confirm the design performance. For the steel damper, three types were designed and their energy dissipation characteristics by hysteretic behavior were confirmed by the inelastic finite element analyses and the tests in static fully reversed cyclic conditions. Through the study of the vertical seismic isolation device, it was found that 2.5 Hz~3.0 Hz is appropriate for the optimal design vertical isolation. With results of the vertical seismic isolation performance analysis, the appropriate number of steel dampers are proposed to limit the vertical seismic displacement of the spring within the static displacement range by the design vertical load.

Research and Development of Three-Dimensional Isolation System for Sodium-Cooled Fast Reactor: Part 3 — Characteristics for Elements on Basis of Half-Scale Loading Tests

2019 ◽  
Author(s):  
Takahiro Somaki ◽  
Tsuyoshi Fukasawa ◽  
Shigeki Okamura ◽  
Takayuki Miyagawa ◽  
Masato Uchita ◽  
...  
Keyword(s):  
Fast Reactor ◽  
Seismic Isolation ◽  
Design Method ◽  
Three Dimensional ◽  
Isolation System ◽  
Rubber Bearing ◽  
In Series ◽  
Loading Tests ◽  
Rubber Bearings ◽  
Disc Spring

Abstract The authors have been developing the three-dimensional isolation system for a Sodium-cooled Fast Reactor, and reported the details of characteristics of disc springs and vertical oil dampers on the basis of full-scale loading tests [1]. To clarify the fundamental characteristics of the three-dimensional isolation system, the loading tests using a half-scale assembled specimen have been planned, which is composed of a rubber bearing, disc spring units, the horizontal supporting functions, the smoothly sliding elements, and the rotate restraint elements. This paper describes each characteristic of the rubber bearings, disc springs and sliding element before assembling a half-scale specimen of the three-dimensional seismic isolation system by the static or dynamic loading. The applicability of design method, the scaling effect in disc springs, and the dependence on the friction coefficient of the sliding elements were investigated and confirmed. Additionally, the method of minimizing the variation of force-displacement relationships between four disc spring units, each of which has the three disc springs stacked in parallel and six disc springs stacked in series, was studied. It should be noted that this paper is in series from Part 2 [1] held on 2018PVP.

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