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

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 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 an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 11 — Improvement of the Seismic Isolator Design Method

2014 ◽  
Author(s):  
Yuji Aikawa ◽  
Hiroshi Hibino ◽  
Yoshitaka Takeuchi ◽  
Shingo Asahara ◽  
Hideo Hirai ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Design Method ◽  
Axial Stress ◽  
Seismic Isolator ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper provides a part of series of “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. This part shows improvements of seismic isolator design method applied to nuclear power facilities. The proposed improvement design methods consist of the following two items. One is an improvement of design method for axial stress in a laminated rubber bearing. Largely different natural frequency in vertical and horizontal direction of the seismic isolator may need a special consideration to combine the design seismic loads in different directions. Therefore isolator’s behavior under multiple direction earthquake is studied, and an improved design method is proposed in the axial stress in a laminated rubber bearing. The other is a reasonable design method for seismic isolator joints. A seismic isolator joint is considered to be one of the key factors for assuring seismic integrity of the seismic isolation system for nuclear power facilities. As a series of design method of seismic isolators, evaluation method of axial force of anchor bolts, among various parts of joints, under design level seismic load is studied and improved method is proposed to confirm the structural behavior for a better performance of the system.

scholarly journals Development of Small-Sized Lead Inserted Laminated Rubber Bearing for Nuclear Component Seismic Isolation

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3193
Author(s):  
Gyeong-Hoi Koo ◽  
Jin-Young Jung ◽  
Jin-Hyeong Lee ◽  
Tae-Myung Shin ◽  
Jin-Young Park
Keyword(s):  
Shear Deformation ◽  
Seismic Isolation ◽  
Damping Ratio ◽  
Test Results ◽  
Performance Parameters ◽  
Shape Factors ◽  
Design Specifications ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing ◽  
Nuclear Component

This paper presents a design specification of the small-sized lead inserted laminated rubber bearing (LRB) for application to nuclear component seismic isolation and describes the results of test verification on design performance parameters such as effective horizontal stiffness, equivalent viscous damping ratio, design seismic isolation frequency, and ultimate shear deformation. To do this, two types of LRB, having the same vertical design load of 10 kN but with different shape factors, are designed, fabricated, and tested by the quasi-static procedures. To determine the effective horizontal stiffness and the equivalent damping value from the test results, the new method is proposed and compared with the methods of the ASCE and ISO standards in case that the tangential stiffness curve is not linear in tests. From the comparison between tests and design specifications in the performance parameters, it was found that the design specifications developed in this paper are in a good agreement with the test results. Furthermore, the target design shear deformation limits are confirmed to have sufficient design margins in ultimate shear deformation tests.

Stability of laminated rubber bearing and its application to seismic isolation

1999 ◽  
Vol 13 (8) ◽  
pp. 595-604 ◽  
Author(s):  
Gyeong-Hoi Koo ◽  
Jae-Han Lee ◽  
Hyeong-Yeon Lee ◽  
Bong Yoo
Keyword(s):  
Seismic Isolation ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing

scholarly journals A comparative study of base isolation devices in light rail transit structure featured with lead rubber bearing and friction pendulum system

2018 ◽  
Vol 195 ◽  
pp. 02013
Author(s):  
Santi Nuraini ◽  
Asdam Tambusay ◽  
Priyo Suprobo
Keyword(s):  
Seismic Isolation ◽  
Time History ◽  
Light Rail ◽  
Rail Transit ◽  
Light Rail Transit ◽  
Pendulum System ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Friction Pendulum ◽  
Friction Pendulum System

Advanced nonlinear analysis in light rail transit (LRT) structures has been undertaken to examine the influence of seismic isolation devices for reducing seismic demand. The study employed the use of two types of commercially available bearings, namely lead rubber bearing (LRB) and friction pendulum system (FPS). Six LRT structures, designed to be built in Surabaya, were modelled using computer-aided software SAP2000, where each of the three structures consisted of three types of LRB and FPS placed onto the pier cap to support the horizontal upper-structural member. Nonlinear static pushover and dynamic time history analysis with seven improved ground motion data was performed to gain improved insights on the behavioural response of LRT structures, allowing one to fully understand the supremacy of seismic isolations for protecting the structure against seismic actions. It is shown that both devices manage to isolate seismic forces, resulting in alleviation of excessive base shear occurring at the column. In addition, it is noticeable that the overall responses of LRB and FPS shows marginal discrepancies, suggesting both devices are interchangeable to be used for LRT-like structures.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 6 — Scaled Tests to Obtain Basic Characteristics of Lead Rubber Bearing

2014 ◽  
Author(s):  
Tsutomu Hirotani ◽  
Ryota Takahama ◽  
Masaki Yukawa ◽  
Hiroshi Hibino ◽  
Yuji Aikawa ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Loading Test ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Basic Characteristics ◽  
Isolation Systems ◽  
Seismic Isolation Systems ◽  
Hysteresis Characteristics

This paper provides a series comprising the “Development of Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. Part 6 presents scaled tests for Lead Rubber Bearing (LRB) newly developed for this project. Following tests are performed to obtain the basic characteristics of LRB,. (1) Horizontal and Vertical Simultaneous Loading Test: LRBs with diameter of 250mm are tested dynamically under simultaneous axial and lateral loading. The hysteresis characteristics is not changed under compressive load although it is changed under tensile load. (2) Basic Break Test: LRBs with a diameter of 800mm are tested statically under various combinations of axial and lateral forces. The hysteresis characteristics model of LRB is determined by this test. It is confirmed that the breaking strain of LRB under compression load exceeds 450%. (3) Horizontal Hardening and Vertical Softening Test: For LRBs with a diameter of 1200 mm, 75% scale of actual LRB are tested statically for horizontal hardening and vertical softening regions. It is confirmed that the hysteresis model which is developed by smaller LRBs is applicable to these large scale models.

scholarly journals Improving the Seismic Behavior of Symmetrical Steel Structures Under Near-Field Earthquake Using a Base Isolation Method Lead Rubber Bearing Isolator

2016 ◽  
Vol 10 (7) ◽  
pp. 10
Author(s):  
Musa Mazji Till Abadi ◽  
Behnam Adhami
Keyword(s):  
Seismic Isolation ◽  
Retaining Wall ◽  
Vertical Component ◽  
Steel Structures ◽  
Vertical Movements ◽  
Near Fault ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Fixed Base ◽  
Near Fault Earthquakes

<p>In this study, the function and application of seismic isolation system through lead rubber bearing isolator (LRB) in near-fault earthquakes are compared with fixed-base structures. As a result of their high frequency content, near-fault earthquakes impose huge energy on structures and cause severe damages. One of the appropriate solutions for this issue is the use of LRB which decreases the amount of imposed energy on structures. To improve the function of isolated structures under the near-fault earthquakes, isolators are designed in a way to tolerate the vertical component of earthquakes. To this purpose, we limit the displacements due to the horizontal movements of isolator through Gap spring which acts as a retaining wall and prevent shocks to other buildings. Moreover, this approach decreases the vertical movements of isolators and indirectly improves their behavior. In the current study, three buildings with four, eight, and 12 floors (with and without gap spring) were included. Isolators were manually designed in accordance with AASHTO-LRB regulations and the behaviors of both isolators and buildings are considered non-linear. Then we analyzed and compared the amount of energy, displacement, and acceleration of structure at the center of roof. The results indicated a significant decrease in the results of base shear, the acceleration of roof center, floors drift and energy imposed on the structure in the isolated system in comparison with the fixed-base structure.</p>

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