城市超宽桥的地震反应分析

以某三跨连续梁桥为工程背景,采用时程分析法,对43.5 m宽的四柱和双柱式超宽桥以及25.5 m宽的普通桥的地震反应进行分析.结果表明：双柱超宽桥主梁稳定性较差,在抗震设计时需要充分考虑主梁的扭转效应;超宽桥地震反应明显大于普通桥,其桥墩弯矩和支座剪力达到普通桥的2～4倍;四柱超宽桥横桥向地震反应起控制作用,双柱式超宽桥纵、横向地震反应均较大;桥墩的布置方式和支座的约束形式对超宽桥地震反应影响较大,双柱式超宽桥更为不利.

Seismic Response Analysis of the Super Wide Bridge of the City

Taking a three-span continuous girder bridge as the engineering background,using time -history analysis method,the passage makes a seismic response analysis about a bridge of 43.5 m width of four column,a bridge of 43.5 m width of double column and a normal bridge of 25.5 m width.The results of calculation indicate that,the stability of the girders about the super-bridge of double column is poor.In seismic design,we need to fully consider the torsion effect of the main girder; the seismic response of the super-wide bridge is significantly greater than the ordinary,the moment of the bridge piers and the shear of the bearing are 2 ～ 4 times of the ordinary.The seismic response of the super-wide bridge on the transverse plays a control role.Seismic response of the super-wide bridge of the double column on longitudinal and transverse is larger.The effects of the bridge piers arrangement and support constraint to seismic response of the super-wide bridge of the city are great.The super wide bridge of double column is more adverse.