九度地震区近断层高速铁路简支梁桥减隔震支座系统研究

Research on Seismic Isolation Bearing System of Near-Fault High Speed Railway Simply Supported Girder Bridge in Nine-Degree Earthquake Area

通过对渝昆(重庆—昆明)高速铁路九度地震区近断层地震动人工地震波进行反应谱分析,发现近断层地震动比远场地震动对高速铁路简支梁桥结构安全威胁更大,提出采用双曲面球型减隔震支座+剪力榫组合的减隔震支座系统进行抗震设计,并对其减震原理予以阐述。以近断层人工地震波为地震动输入,分别对10 m高实心墩和20 m高空心墩的五跨简支梁进行非线性时程分析。以普通支座作为参照,对比分析双曲面球型减隔震支座和双曲面球型减隔震支座+剪力榫组合的减隔震支座系统的减震性能。结果表明,九度地震区近断层高速铁路简支梁桥须采用减隔震支座系统才能满足结构抗震设计要求。

The response spectrum of the artificial seismic wave of near-fault ground motion in the nine-degree earthquake area of Chongqing-Kunming high speed railway was analyzed,it is found that the near-fault ground motion is more dangerous to the safety of the simply supported girder bridges on high speed railway than far-site ground motion.So the seismic isolation bearing system combined double-spherical seismic bearing+shear tenon was proposed for the seismic while five-span simply supported girders with 10 m high solid pier and 20 m high hollow pier respectively were applied to non-linear time history analysis.Using ordinary bearings as a reference,seismic isolation performances of double-spherical seismic bearing and the seismic isolation bearing system combined double-spherical seismic bearing+shear tenon were compared.The results indicate that the seismic isolation bearing system is required to meet the seismic design of structures for the near-fault simply supported girder bridges in the nine-degree earthquake area.