考虑轨道约束的高铁简支梁桥横向地震碰撞效应

Transverse seismic pounding effect for simply-supported girder bridges of high-speed railway considering track constraint

为准确把握地震激励下高速铁路简支梁桥横向挡块的限位功能和防碰减震效果,以5跨32 m标准跨径简支梁桥为例,基于ABAQUS软件建立实体有限元模型;分析轨道系统约束作用、挡块材料非线性对横向碰撞有限元模型的影响;对不同地震波和峰值加速度激励、挡块-垫石间距、挡块强度、橡胶缓冲垫层的厚度等因素进行分析。研究结果表明:轨道约束作用会改变桥梁结构的动力特性与地震碰撞效应,挡块材料非线性对横向碰撞效应影响显著;在不同地震波和不同峰值加速度作用下,桥梁横向地震响应有明显差异;在EI-Centro地震波激励下,综合考虑各项碰撞效应,高速铁路简支梁桥挡块-垫石间距设置为3 cm是合理的;橡胶缓冲垫层会降低墩梁横向相对位移和碰撞力,且防碰减震效果与橡胶的厚度有关。

In order to accurately understand the limit function and earthquake mitigation effect of the transverse shear key of the high-speed railway simply-supported girder bridge during earthquake excitation,taking 5-span 32 m standard span simply-supported bridge as an example,a solid finite element model was established based on ABAQUS software.The effects of track constraint and shear key material nonlinearity on the transverse pounding finite element model were analyzed.The parameters of different seismic waves and different peak acceleration excitations,the initial gap between shear keys and bearing bases,the shear key strength and the thickness of the rubber cushion layer were analyzed.The results show that the track constraint will change the dynamic characteristics of the bridge structure and the seismic pounding effects,and shear key material nonlinearity significantly influences on the transverse pounding effects.Transverse pounding effects are significantly affected by different seismic waves and different peak accelerations.In EI-Centro seismic wave excitation and considering all the pounding effects,the initial gap with 3 cm of the high-speed railway simply-supported girder bridge between shear keys and bearing bases is reasonable.Rubber pads can reduce the transverse relative displacement of the pier and the girder and pounding force,and the effect of anti-collision is related to the thickness of the rubber cushion layer.