scholarly journals Evaluation of Seismic Performance Focusing on Increasing Response of Lead Rubber Bearing (LRB) and Over Strength of RC Pier During Earthquake

2020 ◽  
pp. 33-50
Author(s):  
Naito Nobuyuki ◽  
Park Kyeonghoon ◽  
Mazda Taiji ◽  
Uno Hiroshige ◽  
Kawakami Masahide
Keyword(s):  
Shear Strain ◽  
Seismic Performance ◽  
Elastic Behavior ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Laminated Rubber Bearing ◽  
Current Design ◽  
Rubber Bearings ◽  
Bearing Behavior

The characteristics of the seismic bearing change depending on various factors. When an earthquake occurs, the behavior of the bridge may differ from the values expected in the structural design. The shear deformation of the seismic bearing may increase, but it is difficult to reach the fracturede formation. This paper studied the effect of the stiffness due to various dependency and durability on Lead Rubber Bearings (LRB) and the over strength of bridge piers on the bearing behavior when an earthquake occurred. As a result, if the stiffness of LRB reduces within the criteria, seismic performance can be expected safety even if the shear strain designed in the current design is greater than the allowable shear strain. The reason is that the hardening phenomenon in the high strain region of the laminated rubber bearing suppresses the displacement. Also, since the seismic bridges with over strength of the piers have come near elastic behavior when an earthquake occurs, shear strain is easy to be large.

Derailment of trains moving on lead rubber bearing bridges under seismic loads

2020 ◽  
Vol 26 (19-20) ◽  
pp. 1646-1655
Author(s):  
Shen-Haw Ju
Keyword(s):  
Finite Element ◽  
Seismic Loads ◽  
Base Shear ◽  
Natural Period ◽  
Train Derailment ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Dominant Period ◽  
Rubber Bearings

This study investigates the derailment of trains moving on bridges with lead rubber bearings. A moving wheel/rail axis element that couples two wheels and rails together is first developed to generate a train finite element model with 12 cars, while the sliding, sticking, and separation modes of the wheels and rails are accurately simulated. The finite element results indicate that the base shear of the bridge with lead rubber bearings is much smaller than that without lead rubber bearings. Similar to the base shear, the train derailment coefficients for the bridge with lead rubber bearings are much smaller than those without lead rubber bearings because yield lead rubber bearings during large seismic loads can change the bridge natural frequency to avoid resonance. For earthquakes with a very long dominant period, the lead rubber bearing effect to reduce the train derailment may not be obvious because the natural period of the bridge due to the full yield of lead rubber bearings can approach the dominant period of the earthquake.

Research on Isolated Strengthening of Erose School Buildings

2011 ◽  
Vol 94-96 ◽  
pp. 1298-1303
Author(s):  
Xi Sen Fan ◽  
Shu Zhen Ren
Keyword(s):  
Seismic Response ◽  
Masonry Structure ◽  
School Buildings ◽  
Isolation System ◽  
Torsional Response ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Rubber Bearings ◽  
Strengthening Technique

The aseismatic strengthening technique for masonry structure was researched in this paper. The seismic response of a L-type school building with and without isolation system were computed by using software SAP2000. The isolation system were made up of lead rubber bearings or combined Isolation system. The results showed that base-isolated strengthening can reduce not only the translational response but also the torsional response with earthquake. The combined Isolation system was more effetive in decreasing translational response than the lead rubber bearing, but inferior to in decreasing torsion response.

The Effects of the Rubber Bearing on the Seismic Performance of the Aqueduct-Water Coupling Structure

2013 ◽  
Vol 275-277 ◽  
pp. 1370-1373
Author(s):  
Qiu Hua Duan ◽  
Dan Dan Zeng ◽  
Lu Feng Yang
Keyword(s):  
Numerical Analysis ◽  
Temperature Stress ◽  
Seismic Performance ◽  
Water Depth ◽  
Coupling Structure ◽  
Rubber Bearing ◽  
Bridge Structures ◽  
Rubber Bearings ◽  
Water Bridges

Rubber bearings are widely used in bridge structures. The aqueduct structures are water bridges, so rubber bearings are often set at the end of the aqueducts. Rubber bearing cannot solve the problems such as temperature stress and supporting inhomogeneous settlement, but also play role of isolation damping. This paper mainly studies on the effects of the water-depth with changing rubber bearing on the seismic performance of the aqueduct-water coupling structure by numerical analysis.

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.

Longitudinal seismic response control of long-span cable-stayed bridges using shape memory alloy wire-based lead rubber bearings under near-fault records

2017 ◽  
Vol 29 (5) ◽  
pp. 703-728 ◽  
Author(s):  
Shuai Li ◽  
Farshad Hedayati Dezfuli ◽  
Jing-quan Wang ◽  
M Shahria Alam
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Alloy Wire ◽  
Base Shear ◽  
Alloy Wire ◽  
Near Fault ◽  
Long Span ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Rubber Bearings

This article investigates the efficiency of a new generation smart isolation system, namely shape memory alloy wire-based lead rubber bearing, for the seismic response control of long-span cable-stayed bridge systems under near-fault ground motions. The constitutive model of shape memory alloy wire-based lead rubber bearings is coded and implemented into OpenSees as a new user element. This user element can accurately predict the re-centering capability and energy dissipation capacity of shape memory alloy wire-based lead rubber bearing under different excitations. The Sutong cable-stayed bridge in China, with a main span of 1088 m, is taken as an example. Results reveal that implementing shape memory alloy wires into lead rubber bearings can effectively increase the self-centering property and, as a result, reduce the residual deformation in shape memory alloy wire-based lead rubber bearings under near-fault ground motions. Shape memory alloy wires lead to an increase in the horizontal stiffness and energy dissipation capacity of shape memory alloy wire-based lead rubber bearings. The deck displacement is restricted effectively, and a superior structural performance is achieved in terms of the deck acceleration. Shape memory alloy wire-based lead rubber bearings can effectively reduce the base shear and base moment of the towers. However, it is observed that an increase in the shape memory alloy wire diameter may have negligible effect on the deck acceleration, tower base shear and moment, and in some cases, on the pier base shear and moment.

Design of Shape Memory Alloy Damper for Base Isolated Structure

1997 ◽  
Author(s):  
Krzysztof Wilde ◽  
Paolo Gardoni ◽  
Yozo Fujino ◽  
Stefano Besseghini
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Base Isolation ◽  
Hysteretic Behavior ◽  
Isolation System ◽  
Rubber Bearing ◽  
Laminated Rubber Bearing ◽  
Base Isolation System ◽  
Rubber Bearings ◽  
Smart Base Isolation

Abstract Base isolation provides a very effective passive method of protecting the structure from the hazards of earthquakes. The proposed isolation system combines the laminated rubber bearing with the device made of shape memory alloy (SMA). The smart base isolation uses hysteretic behavior of SMA to increase the structural damping of the structure and utilizes the different responses of the SMA at different levels of strain to control the displacements of the base isolation system at various excitation levels. The performance of the smart base isolation is compared with the performance of isolation by laminated rubber bearings to assess the benefits of additional SMA damper for isolation of three story building.

The Behavior of Bearings Used for Seismic Isolation under Rotation and Axial Load

1999 ◽  
Vol 15 (2) ◽  
pp. 225-244 ◽  
Author(s):  
Atsushi Mori ◽  
Peter J. Moss ◽  
Nigel Cooke ◽  
Athol J. Carr
Keyword(s):  
Seismic Isolation ◽  
Axial Loads ◽  
Isolation System ◽  
Elastomeric Bearings ◽  
Lead Rubber Bearings ◽  
Combined Action ◽  
Lift Off ◽  
Rubber Bearings ◽  
Bearing Behavior ◽  
Angle Of Rotation

The investigation described in this paper looked at both laminated elastomeric bearings and lead-rubber bearings in order to obtain a better understanding of the real bearing behavior under the combined action of rotation and axial loads when used in a seismic-isolation system. In particular, the investigation focused on the distributions of vertical pressure on the bearing faces and the degree of lift-off of the edges of the bearings as the angle of rotation increased.

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