Study on Seismic Isolation of Electrical Transformer by Lead Rubber Bearing

2021 ◽  
Author(s):  
Sheng Li ◽  
Zhicheng Lu ◽  
Yingying Zhang ◽  
Kewei Luo ◽  
Haibo Wang ◽  
...  
Keyword(s):  
Seismic Isolation ◽  
Rubber Bearing ◽  
Lead 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>

Study of Vertical Seismic Isolation of Self-Anchored Cable-Stayed Suspension Bridge Based on Lead Rubber Bearing

2014 ◽  
Vol 904 ◽  
pp. 520-523
Author(s):  
Feng Miao
Keyword(s):  
Seismic Isolation ◽  
Suspension Bridge ◽  
Stiffness Analysis ◽  
Seismic Input ◽  
Damping Characteristics ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Yield Force

Based on the background of Dalian Bay Cross-Sea Bridge project, some plans with settings of lead-rubber bearing among side pier, tower and stiffening girder have been analyzed under vertical seismic input using the favorable shearing property of laminated rubber, damping characteristics of lead and reasonable parameters (yield force and stiffness). Analysis results show that the displacement of controlling node and force of controlling section have been reduced.

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.

scholarly journals Recent research and applications of seismic isolation in New Zealand

1995 ◽  
Vol 28 (4) ◽  
pp. 253-264 ◽  
Author(s):  
W. H. Robinson
Keyword(s):  
New Zealand ◽  
Los Angeles ◽  
Seismic Isolation ◽  
Strong Support ◽  
Industrial Plant ◽  
Northridge Earthquake ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Seismically Isolated ◽  
Bearing System

In New Zealand, seismic isolation, the technique in which the structure is decoupled from earthquake-induced ground motions, has now advanced to the point where it is often considered for the protection of both new and existing buildings, bridges, and to a lesser extent, industrial plant. Many of the devices used in these applications have been developed in our laboratory. We describe here how the lead-based devices operate, and we give some examples of the application of seismic isolation to structures m New Zealand. Current interest is focused on the application of seismic isolation to three buildings in central Wellington. In July 1993, the construction of the seismically isolated Museum of New Zealand was started on the Wellington waterfront. All of the lead-rubber isolators have now been tested and installed. Nearby the NZ Parliament Building and Library have been retrofitted with a lead-rubber bearing system. To support the continuation of improvements to the seismic resistance of structures a number of research programs are operating in the Universities of Auckland and Canterbury, the Engineering Seismology Section of the NZ Institute of Geological and Nuclear Sciences, Works, a number of engineering consultants and in our company. Very strong support for the principles of seismic isolation is given by the fact that of the ten hospitals affected by the 1994 Northridge earthquake in Los Angeles, only the hospital seismically isolated by a lead-rubber bearing system was able to continue to operate. Further support is given by the excellent behaviour of two isolated buildings in the 1995 Hyogo Ken-Nanbu earthquake.

scholarly journals Link Slab Capacity In Bridges Supported By Lead Rubber Bearing And Elastomer

2019 ◽  
Vol 24 (2) ◽  
pp. 73
Author(s):  
Inas Novikasari ◽  
Anis Rosyidah
Keyword(s):  
Seismic Isolation ◽  
Design Criteria ◽  
Isolation System ◽  
Expansion Joints ◽  
Debris Accumulation ◽  
Seismic Isolator ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Seismic Force ◽  
High Level

Debris accumulation in bridge slab gaps which use expansion joints can restrain deck expansion, causing undesirable forces on floor deck and damage to the structure. In order to avoid the worst possibility that can occur, an alternative using link slab is utilized. The use of link slab at high level seismic force location, requires the Seismic Isolation System on bridge to reduce the seismic force. The application of Seismic Isolation System can be conducted by Lead Rubber Bearing (LRB) type of seismic isolator. This study compares the use of Lead Rubber Bearing (LRB) and elastomer on bridge link slabs against the dimension of the link slab. In this study structural modeling used 2 models: bridges supported by elastomer and bridges supported by LRB with software-made. The link slab analysis approach used were analytical methods or classical methods. Based on results of the analysis, the width of the crack that occured on bridge supported by LRB is 0.218 mm while on the bridge supported by elastomer is 0.269 mm. The use of Lead Rubber Bearing (LRB) type of support will give more advantages to the design of the link slab since it results in smaller crack design criteria.

scholarly journals Recent developments in devices for seismic isolation

1992 ◽  
Vol 25 (3) ◽  
pp. 167-174 ◽  
Author(s):  
W. J. Cousins ◽  
W. H. Robinson ◽  
G. H. McVerry
Keyword(s):  
New Zealand ◽  
Seismic Isolation ◽  
Performance Characteristics ◽  
Printing Press ◽  
Police Station ◽  
Capacitor Banks ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Recent Developments ◽  
Central Police

Significant extensions to the technology for seismic-isolation were required for three recent applications in New Zealand. The structures isolated were a new Central Police Station in Wellington, a printing press hall built in Petone for Wellington Newspapers Ltd., and capacitor banks at Haywards substation near Lower Hutt. In each case the isolating devices were tested to verify their performance characteristics. This paper presents the results of the testing. The devices were a lead-extrusion damper rated at 250 kN load ± 400 mm stroke, a lead-rubber bearing measuring 609 mm x 609 mm x 460 mm, and a steel taper-beam damper rated at 10.6 kN load ± 200 mm stroke.

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