Abstract

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Title:: Research on Seismic Isolation Characteristics of LRB for Simply Supported Beam Bridge

Author(s):: LIU Xin-hua; LI Jia-wu; ZHOU Qin; HUANG Sen-hua; CCCC Second Highway Consultants Co. Ltd

Keywords:: bridge engineering; simply supported bridge; LRB; seismic isolation design; damping rate; dynamic characteristics

Abstract:: Taking a 4×40 m simply supported Tgirder bridge as example, comparative analysis of nonisolated design by conventional plate type elastomeric pad bearings and seismic isolation design by lead rubber bearing （LRB） was done, and the bridge structure dynamic characteristics of the two bearing design were compared. Furthermore, the structural internal force and displacement response differences between isolation design bridge and nonisolation design were also compared. In other conditions consistent with the premise， the influence of mechanical parameters of LRB on seismic isolation was studied. Study results show that plate type elastomeric pad bearings design of LRB can extend the period of bridge structure； the designed LRB has obvious damping effect， and LRB can greatly reduce shear and moment at the pier bottom， and each pier again tends to balance and reasonably distributes the seismic forces. In seismic isolation design， the blind pursuit of increasing LRB models will give the bridge substructure adversely affected.