软土地区铁路桥大直径群桩基础的大型厚承台设计实践

摘要

针对软土地区铁路桥大直径超长群桩基础，以甬江铁路桥为背景，采用有限元数值分析（三维实体模型）、撑杆-系杆体系、梁式体系3种计算方法对超大桩头力、不等长桩的铁路桥梁大型厚承台进行计算。结果表明，不等长桩的大型厚承台在强大荷载作用下，基础位移及基础变位所致塔顶位移均不显著，而承台底面主拉应力较大，需作配筋设计和验算。%As for the super-long large-diameter pile group foundation of railway bridges in the soft soil area,based on the background of Yongj iang Railway Bridge,three methods including three-dimen-sional finite element method (3D FEM),strut-tie system and beam system were adopted to calculate the working performance of railway large-scale thick pile cap with unequal-length piles and huge forces on the pile heads in this paper.As to the thick pile cap with unequal-length piles,the results show that the deformations of the foundation and the displacements on the top of the towers are all non-sig-nificant,and the principal tensile stress on the bottom of the pile cap is great which means that rein-forcement design and calculation should be accomplished.