Seismic isolation of highway bridges: Effective performance of LRBs at low temperatures

2015 ◽  
pp. 279-286
Author(s):  
C Galindo ◽  
G Moor ◽  
B Bailles
Author(s):  
Kazuhiko Kawashima ◽  
Shigeki Unjoh

This paper presents the seismic isolation design code for highway bridges. This is based on the 1996 Design Specifications for Highway Bridges, Part. V: Seismic Design, issued by the Japan Road Association in December 1996. This paper focuses on the outlines of the seismic isolation design code including the seismic design basic principles, design ground motion, and seismic isolation design.


2010 ◽  
Vol 136 (5) ◽  
pp. 502-510 ◽  
Author(s):  
George C. Lee ◽  
Yu-Chen Ou ◽  
Tiecheng Niu ◽  
Jianwei Song ◽  
Zach Liang

1999 ◽  
pp. 57 ◽  
Author(s):  
J.M. Kelly

The first seismically isolated building in the United States was completed in 1985. In the fourteen years since then, a total of not more that twenty-five new buildings and twenty-two retrofits of existing buildings hass been completed. In constrast, the number of base-isolated building in Japan completed over the same time period is of the order of a few hundred, and in China, where the first isloated building was completed in 1995, there are now over seventy base-isolated building.Currently there are several building codes that govern the desing of base-isolated buildings in the United States. New regulations have been prepared for the year 2000 and beyond, which are both complex and conservative, discouraging the use of seismic isolation. These codes require the engineer to desing isolators for very large displacements and mandate extensive prototype and production testing, thereby restricting isolation's application to special structures such as hospitals and emergency service centers where a requirement for operational functionality following large earthquake events justifies the cost premium and time delays associated with the use of seismic isolation.Conversely, seismic isolation is widely used throughout the United States for highway bridges and is governed by a single desing code that is simple tob use and not overly conservative. Isolation systems are being used for the retrofit of several very large bridges in California. The isolators to be used for this projects are very large, and a test machine at the University of California, San Diego (UCSD), has just been completed to test these Isolators at full-scale, real-time rates.This paper will describe the current regulatory evironment for seismic isolation and the testing requirements for isolators. A description of the new test facility at UCSD will be included. 


2021 ◽  
Author(s):  
Hiroshi Shimmyo ◽  
Tolga Onal ◽  
Shozo Nakamura ◽  
Kazuya Tokunaga

<p>In the current Specifications for Highway Bridges of the Japan Road Association, a bilinear force- displacement relationship is recommended as the hysteresis loops of the seismic isolation rubber bearings for the dynamic structural analysis of seismically isolated bridges. However, it has been confirmed that the restoring force characteristics of the actual devices are different from the bilinear model due to the Mullins effect and the hardening phenomenon of the rubber under large shear strains. In this study, the effect of these two factors on the seismic response of a bridge is investigated through the dynamic analysis with the tri-linear double target model considering the factors. The parameters of the model are obtained from product test results of lead-plugged laminated rubber bearings and high-damping laminated rubber bearings.</p>


1992 ◽  
Vol 118 (1) ◽  
pp. 284-304 ◽  
Author(s):  
Ronald L. Mayes ◽  
Ian G. Buckle ◽  
Trevor E. Kelly ◽  
Lindsay R. Jones

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