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.

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.

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.

Laminated Type Isolation Device for Light Weight Structure Using Urethane Elastomer

2017 ◽  
Author(s):  
Kengo Goda ◽  
Osamu Furuya ◽  
Kohei Imamura ◽  
Kenta Ishihana
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Light Weight ◽  
Loading Test ◽  
Isolation System ◽  
Seismic Safety ◽  
Base Isolation System ◽  
Weight Structure ◽  
Isolation Device ◽  
Urethane Elastomer

At the present, base isolation system has been recognized by general earthquake resistant technique since the Great Hanshin Earthquake 1995. The seismic isolation will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In generally, although the base isolation system is divided into laminated rubber bearing type and friction sliding bearing type. In the case of former type, shape factor, maximum or minimum outer shapes and so on are restricted by the material characteristics in visco-elastic material. In general, the isolation structure is used in high damping rubber. However, we pay attention to base isolation using urethane elastomer. Urethane elastomer has excellent elasticity, mechanical strength, abrasion resistance, weather resistance, oil resistance, impact resistance the absorbent, anti-vibration and excellent low-temperature properties. Furthermore, it is possible to impart various characteristics by a combination of isocyanate and polyol and chain extender, requires no large-scale apparatus, it has the advantage molecular design is easy. In previous study, the research and development of laminated type base isolation device using urethane elastomer was carried out to upgrade a seismic safety for various structures. The fundamental characteristics was investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. It was confirmed that urethane elastomer is not hardening up to 500% shear strain. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. As the results, it was confirmed that the laminated type seismic isolation device using urethane elastomer is possible to develop as a practicable device from the stable mechanical properties as considering in design step. In this study, the small-scale laminated type base isolation device using urethane elastomer is advanced to the direction of further technical upgrading and of scale down for light-weight structure as a sever rack. The first stage, basic properties of the urethane elastomer has been investigated by loading test. Furthermore, the design equation is created by loading test using urethane elastomer. The validity of the design equation has been confirmed. The second stage, the compression creep test with laminated type base isolation device has been investigated to confirm an effect on light-weight mechanical devices.

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.

A study on seismic isolation of building used LRB

2020 ◽  
Vol 6 (2) ◽  
pp. 52
Author(s):  
Muhammet Yurdakul ◽  
Mehmet Burak Yıldız
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Dynamic Loads ◽  
Isolation System ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Earthquake Design ◽  
Base Isolation System ◽  
Internal Forces ◽  
Storey Building

Base isolation system with lead rubber bearing (LRB) is commonly used to prevent structure against to damage of earthquake. Design of LRB system is detailed in this study. The isolated building with LRB design according to Uniform Building Code (UBC-97) and fixed building were examined. The six-storey building with LRB and fixed building were modelled in SAP2000 with the same dynamic loads. The relative floor displacement and internal forces of the seismic isolated and fixed building are compared. In addition, transverse and longitudinal reinforcement of any axis of seismic isolated and fixed building are compared. Analyse results showed that effectiveness of using seismic isolation system on building. The weight of longitudinal and transverse reinforcement of isolated building is smaller than fixed building about 36%, 40% respectively.

Study on Three-Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant: Hydraulic Three-Dimensional Base Isolation System

2004 ◽  
Author(s):  
Takahiro Shimada ◽  
Tatsuya Fujiwaka ◽  
Satoshi Moro
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Dynamic Test ◽  
Development Project ◽  
Response Analysis ◽  
Isolation System ◽  
Actual Structure ◽  
Load Carrying ◽  
The Government

In Japan, a number of three-dimensional base isolation systems have been studied for application to new nuclear plant concepts such as the FBR, but these efforts have not so far yielded practically applicable results. The impeding factor has been the difficulty of obtaining an adequate capacity on the vertical isolator for supporting the mass of an actual structure and for suppressing rocking motion. In this paper, we propose a new three-dimensional isolation system that should solve the foregoing problem. The system is constituted of a set of hydraulic load-carrying cylinders connected to accumulator units containing compressed gas, a set of rocking-suppression cylinders connected in series, and a laminated rubber bearing laid under each load-carrying cylinder. The present paper covers a basic examination for applying the proposed system to a FBR plant now under development in Japan. In order to verify expected system performance, the load-carrying cylinders were first tested independently of rocking-suppression cylinders, and this was followed by integrated dynamic test of the system incorporating both load-carrying and rocking suppression cylinders. Response analysis reflecting the test results has indicated the proposed system to be well applicable to the envisaged commercialized FBR. The study was undertaken as part of a research and development project sponsored by the government for realizing a three-dimensional seismic isolation system applicable to future FBR.

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