Study on Seismic Isolation of High-Speed Railway Bridge Fabricated Lead Rubber Bearings

2011 ◽  
Vol 80-81 ◽  
pp. 409-413 ◽  
Author(s):  
Huan Tang ◽  
Hui Wang ◽  
Biao Zhou ◽  
Ling Kun Chen
Keyword(s):  
High Speed ◽  
Seismic Isolation ◽  
Computational Method ◽  
Bridge Engineering ◽  
Design Parameters ◽  
Vehicle Speed ◽  
Widespread Application ◽  
Bridge Model ◽  
Lead Rubber Bearings ◽  
Rubber Bearings

Lead rubber bearings (LRB) is a new type of earthquake-resistance rubber bearings, formed by inserting lead-core into ordinary laminated rubber bearings, vertical supporting, horizontal displacement and hysteretic damping are hung in single unit together. Because lead-core can dissipate seismic energy and increase stiffness under load simultaneously, most of the requirements of the Seismic isolation system can be satisfied , the material-device has been found widespread application prospect in bridge Engineering. Equivalent linear model of hysteretic characteristics, computational method and the varying range of design parameters of LRB are presented. A full-bridge model of multi-span simple supported bridge with LRB is established in which box beam、LRB and piers are taken into account as a whole. By changing the property of earthquake excitation, ground motion intensity, vehicle speed and so on, the response of Bridge vibration system are analyzed, response law and characteristics of Bridge with LRB under different excitations are investigated systematically, compared with bridge with common bearings.

Dynamic Properties of Lead Rubber Bearings and its Seismic Isolation Applications in High-Speed Railway Bridge

2010 ◽  
Vol 150-151 ◽  
pp. 164-167 ◽  
Author(s):  
Ling Kun Chen ◽  
Li Zhong Jiang ◽  
Peng Liu
Keyword(s):  
High Speed ◽  
Seismic Isolation ◽  
Dynamic Properties ◽  
Computational Method ◽  
Dynamic Responses ◽  
Railway Bridge ◽  
Widespread Application ◽  
High Speed Railway ◽  
Rubber Bearing ◽  
Rubber Bearings

Lead rubber bearing (LRB) is a new type of earthquake-resistance rubber bearings, formed by inserting lead-core into ordinary laminated rubber bearing, vertical supporting, horizontal displacement and hysteretic damping are hung in single unit together. For lead-core can dissipate seismic energy and increase stiffness under load simultaneously, and most of the requirements of the Seismic isolation system can be satisfied, the material-device has been found widespread application prospect in bridge engineering. Hysteretic behaviors, ductility, and energy dissipation of LRB are mainly determined by some dynamical parameters such as characteristic intensity of LRB, post-yield, pre-yield stiffness and so on. Equivalent linear model of hysteretic characteristics, computational method and the varying range of dynamic parameters of LRB are presented. Dynamic responses of high-speed railway bridge fabricated LRB are calculated, and calculation results are compared with those fabricated common bearings, factors which influence seismic isolation are analyzed.

scholarly journals Numerical Study of Longitudinal Inter-Distance and Operational Characteristics for High-Speed Capsular Train Systems

Vehicles ◽  
2022 ◽  
Vol 4 (1) ◽  
pp. 30-41
Author(s):  
Bruce W. Jo
Keyword(s):  
Error Rate ◽  
High Speed ◽  
Position Control ◽  
Numerical Study ◽  
Design Parameters ◽  
Maximum Speed ◽  
Integer Number ◽  
Vehicle Speed ◽  
Start Time ◽  
Distance Control

High-speed capsular vehicles are firstly suggested as an idea by Elon Musk of Tesla Company. Unlike conventional high-speed trains, capsular vehicles are individual vessels carrying passengers and freight with the expected maximum speed of near 1200 [km/h] in a near-vacuum tunnel. More individual vehicle speed, dispatch, and position control in the operational aspect are expected over connected trains. This numerical study and investigation evaluate and analyze inter-distance control and their characteristics for high-speed capsular vehicles and their operational aspects. Among many aspects of operation, the inter-distance of multiple vehicles is critical toward passenger/freight flow rate and infrastructural investment. In this paper, the system’s equation, equation of the motion, and various characteristics of the system are introduced, and in particular control design parameters for inter-distance control and actuation are numerically shown. As a conclusion, (1) Inter-distance between vehicles is a function of error rate and second car start time, the magnitude range is determined by second car start time, (2) Inter-distance fluctuation rate is a function of error rate and second car start time, however; it can be minimized by choosing the correct second car start time, and (3) If the second car start time is chosen an integer number of push-down cycle time at specific velocity error rate, the inter-distance fluctuation can be zero.

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.

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

1999 ◽  
Vol 15 (2) ◽  
pp. 199-224 ◽  
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 shear 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 shearing displacement and the angle of rotation increased.

scholarly journals The implementation of seismic isolation in the retrofit of a large wharf

2003 ◽  
Vol 36 (3) ◽  
pp. 208-217 ◽  
Author(s):  
Barry J. Davidson ◽  
Darrin K. Bell ◽  
Stuart F. George
Keyword(s):  
Seismic Isolation ◽  
Seismic Retrofit ◽  
Design Requirement ◽  
Lead Rubber Bearings ◽  
Lateral Restraint ◽  
Energy Absorbers ◽  
Rubber Bearings ◽  
Ductility Capacity ◽  
Post Tensioned

The paper describes the implementation of lead-rubber bearings as energy absorbers as part of the retrofit and upgrade of a large wharf. The key design requirement of the seismic retrofit was to ensure that the limited ductility capacity of the existing wharf piles was not exceeded. This was achieved by providing additional lateral restraint to the wharf in the form of groups of raking piles fastened to the wharf via post-tensioned lead-rubber bearings acting as energy absorbers.

Some Models of Elastomeric Seismic Isolation Devices

2013 ◽  
Vol 430 ◽  
pp. 356-361 ◽  
Author(s):  
Vasile Iancu ◽  
Gilbert Rainer Gillich ◽  
Claudiu Mirel Iavornic ◽  
Nicoleta Gillich
Keyword(s):  
Natural Rubber ◽  
Mathematical Models ◽  
Seismic Isolation ◽  
Horizontal Displacement ◽  
Numerical Results ◽  
Hysteretic Behaviour ◽  
Hybrid Device ◽  
Mathematical Relation ◽  
Lead Rubber Bearings ◽  
Rubber Bearings

For the study and design of the elastomeric seismic devices is essential to know the mathematical relation between the horizontal displacement and the force leading it. In this paper we present mathematical models for three types of devices: (i) natural rubber bearings, (ii) lead rubber bearings and (iii) hybrid device combining the two first mentioned bearings. For all devices the specific domains of operation are determined and for each domain the relations connecting horizontal displacement and stiffness is contrived, highlighting the hysteretic behaviour in respect to ground excitation. Finally we present numerical results and a comparison between the three devices, defining the opportunity to involve them in specific applications, in function of the type and nature of the isolated structure.

Study on the damping efficiency of continuous beam bridge with constant cross-section applied by lead rubber bearings and fluid viscous dampers

2020 ◽  
Vol 51 (4-5) ◽  
pp. 85-92
Author(s):  
Li Zhen ◽  
Li Dejian ◽  
Peng Leihua ◽  
Lu Yao ◽  
Cheng Kepei ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Seismic Isolation ◽  
Seismic Energy ◽  
Continuous Beam ◽  
External Energy ◽  
Fluid Viscous Dampers ◽  
Continuous Beam Bridge ◽  
Lead Rubber Bearings ◽  
Rubber Bearings ◽  
Beam Bridge

Bridges are the lifelines of disasters in earthquake areas. Therefore, it is very necessary to ensure the safety and traffic function after earthquake. Seismic isolation refers to install external energy dissipation devices or external energy input devices in specific parts of engineering structures. There are certain differences in longitudinal and transverse seismic responses of multi-span continuous beam bridges by changing the seismic dynamic characteristics or dynamic effects of structures. It is difficult to achieve the purpose of seismic isolation in both horizontal directions using isolation devices alone. The rubber deformation ability of lead rubber bearings can effectively insulate, and the yield energy consumption ability of its lead core can effectively consume the seismic energy for damping. The horizontal resistance is very small under the creep load, and the stiffness decreases rapidly after yielding under the strong dynamic earthquake load; meanwhile, the seismic energy is dissipated by the hysteresis of bearing. Fluid viscous damper is a velocity-dependent energy dissipation device, which produces viscous damping force, provides strong restoring force for components, and has a good limit function. This process will also dissipate the seismic energy, so as to reduce the structural earthquake response. Using these two methods together, the horizontal seismic responses of multi-span continuous beam bridges can be effectively controlled at the same time. Based on this idea, this article takes a high-speed multi-span continuous beam bridge with equal section as the engineering background, and uses dynamic time history analysis method to discuss the seismic isolation effect of lead rubber bearings and fluid viscous dampers.

Implementation and Validation of a Numerical Model for Lead-Rubber Seismic Isolation Bearings

2017 ◽  
Vol 35 (02) ◽  
pp. 153-165 ◽  
Author(s):  
T. Zhou ◽  
Y. F. Wu ◽  
A. Q. Li
Keyword(s):  
Numerical Model ◽  
Seismic Isolation ◽  
Model Simulation ◽  
Lateral Displacement ◽  
Piecewise Linear ◽  
Stability Limit ◽  
Lateral Interaction ◽  
Vertical Stiffness ◽  
Lead Rubber Bearings ◽  
Rubber Bearings

ABSTRACTThis paper presents a numerical model for accurately representing the behaviors of lead-rubber bearings during earthquakes. This model, which is implemented in OpenSees as a user-defined element, accounts for the mechanical characteristics of bearings as follows: firstly, the bi-lateral interaction effect of hysteretic behaviors, as well as the variation in horizontal stiffness due to vertical load, is considered; secondly, the reduced vertical stiffness under large lateral displacement is incorporated by the piecewise linear formulation, and the linear reduction method is employed to determine the stability limit of bearings in the deformed configuration; furthermore, the cavitation and permanent damage effects in bearings are mathematically included. To validate the numerical model, simulation analyses are performed for a series of static and dynamic loading tests, and the numerical results show reasonable agreement with experimental ones, which indicates that the proposed model provides an effective tool for the failure mode analyses of bearings and the dynamic analyses of seismic isolated structures.

A Direct Displacement-Based Design Method Based on Chinese Code of Base Isolated Structures

2011 ◽  
Vol 255-260 ◽  
pp. 2555-2559
Author(s):  
Zhen Sun ◽  
Wei Qing Liu ◽  
Shu Guang Wang ◽  
Ding Zhou ◽  
Dong Sheng Du
Keyword(s):  
Seismic Isolation ◽  
Design Method ◽  
Response Spectrum ◽  
Base Shear ◽  
Direct Displacement Based Design ◽  
High Intensity Zone ◽  
Lead Rubber Bearings ◽  
Displacement Based ◽  
Rubber Bearings ◽  
Relationship Of

A simple and efficient direct displacement-based design (DDBD) method is introduced to base isolated (BI) structures. Assuming the vibration mode of superstructure to be the shear type and considering the BI structure to be an equivalent single degree of freedom (ESDOF) system with spring and damper at the seismic isolation layer. The acceleration response spectrum in Chinese code is converted to displacement response spectrum. Corresponding to the design displacement, the equivalent period is obtained. The relationship of the deign displacement, equivalent period, equivalent stiffness and base shear of the system can be derived from the given formulations. Then, the distribution of the base shear along the floors is obtained. This method has been applied to the design of a 12-story BI structure with lead rubber bearings in high intensity zone in Suqian city, Jiangsu province. The results show that the method is feasible for the design of BI structures.

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