路堤下穿对高铁简支梁桥下部结构的侧向效应

Lateral Effects of Embankment Underpass on the Substructure of High-speed Railway Simply Supported Beam Bridges

本文以新建路堤下穿高铁32m简支梁桥为例,建立Midas GTS三维有限元模型,总结了路堤下穿引发的高铁桥梁下部结构侧向效应特点;研究了考虑墩梁间摩擦力作用的墩顶侧移。结果表明:路堤下穿会引起桩基“弓形”侧向变形和墩顶侧移;桩底嵌固区段附加剪力和附加弯矩较大;桩顶区段附加弯矩较大;墩梁间摩擦会限制墩顶侧移,实际工程中宜在高铁桥梁上部结构架设完成后进行路堤下穿施工。

By establishing a Midas GTS three-dimensional finite element model,this article summarizes the lateral effects on the lower structure of the high-speed railway bridge caused by the embankment underpass,and studies the lateral displacement of pier top considering the frictional force between piers and beams.The results indicate that embankment underpass can cause lateral deformation of the pile foundation in a bow shape and lateral displacement of the pier top.The additional shear force and additional bending moment in the embedded section at the bottom of the pile are relatively large.The additional bending moment in the pile top section is relatively large.The friction between the piers and beams will limit the lateral displacement of the pier top.In actual engineering,it is advisable to carry out the construction of the embankment after the completion of high-speed rail installation.