地震作用下双曲面球型减隔震支座在铁路简支梁桥中的动力行为

Dynamic behaviors of double spherical isolation bearing in simply-supported railway bridges under earthquakes

为研究双曲面球型减隔震支座在铁路简支梁桥中的减隔震效果,采用ABAQUS软件建立8m及25m墩高的铁路简支梁桥有限元模型,进行地震荷载作用下的非线性动力时程分析。通过对有限元计算结果与振动台模型试验结果进行对比,验证有限元模型的正确性。与普通球型钢支座作对比,分析地震作用下双曲面球型减隔震支座的水平滑动位移、竖向位移和竖向荷载变化等动力行为。研究得到双曲面球型减隔震支座在不同地震烈度下的水平滑动位移范围。研究结果表明:相对于普通支座,双曲面球型减隔震支座在大多数情况下,能明显减小顺桥向地震作用造成的简支梁固定端与滑动端之间的竖向相对位移,对轨道结构造成的不利影响更小;双曲面球型支座能显著降低横桥向地震作用造成的支座竖向荷载变化幅值,并有效避免支座滑动面发生脱离碰撞。

To investigate the seismic isolation effect of double spherical seismic isolation(DSSI)bearings in the simply-supported railway bridges,the finite element models(FEM)of those bridges with pier height of 8 m and25 m were established by the ABAQUS software,and were studied by a nonlinear dynamic time-history analysis under earthquakes.Based on the comparison of finite element calculation results and shaking table test results,the correctness of FEM was verified.The dynamic behaviors,including horizontal sliding displacement,vertical displacement and vertical load change of DSSI bearings under earthquakes,were analyzed and compared with the traditional spherical steel bearings.The horizontal sliding displacement range of DSSI bearings under different seismic intensities was obtained.The results show that when compared with the traditional spherical steel bearings,the DSSI bearings can significantly reduce the vertical relative displacement between the fixed end and the sliding end of the simply-supported girder under longitudinal earthquake effects in most cases,and have less detrimental effects on track structure.The DSSI bearings can significantly reduce the amplitude of vertical load of bearing under transverse earthquake effects and can effectively avoid the separation and collision of sliding surface of bearing.