高速铁路桩筏结构的筏板合理设计研究  

Study on ideal raft design of pile-raft structure in high-speed railway

作　　者：王育恒[1,2] 肖宏 乔少帅[1] WANG Yuheng;XIAO Hong;QIAO Shaoshuai(Beijing Key Lab of Track Engineering,Beijing Jiaotong University,Beijing 100044,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]北京交通大学轨道工程北京市重点实验室,北京100044 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《北京交通大学学报》2021年第2期19-27,共9页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：中央高校基本科研业务费专项资金(2015JBZ004);国家自然科学基金(51978045)。

摘　　要：桩筏结构在高速铁路中的应用较多,但理论研究滞后于工程实践.为得出高速铁路桩筏结构的筏板的合理设计,采用三维有限元软件ABAQUS建立了桩筏结构空间模型,仿真模拟了桩筏结构的应力和沉降,并对筏板沿线路纵横垂三个方向的受力特性与规律进行研究.在此基础上,分析比较了筏板在不同的筏板厚度及垫层厚度时的受力与沉降,从而得出最为合理的筏板厚度及褥垫层厚度,并得到如下结论:1)筏板在桩筏结构中应按抗弯部件设计;2)筏板厚度的增加使得其所受应力呈指数下降;3)褥垫层厚度对筏板的竖向应力影响微小;4)褥垫层在桩筏结构中对缓解筏板竖向应力集中起到了一定的作用.本文研究结论为今后桩筏结构的设计及数值模拟提供了参考.Pile-raft structure is widely used in high-speed railway,but the theoretical research lags behind the engineering practice.In order to obtain the rational design of the raft,a three-dimensional space model of pile-raft structure is established with the finite element software ABAQUS to simulate the stress and settlement of pile-raft structure.Then the mechanical characteristics and laws of the raft board along the vertical and horizontal directions are studied.On this basis,this paper compares and analyzes the stress and settlement of pile-raft structure under different raft thickness and different cushion thickness,and the most reasonable raft thickness and cushion thickness are obtained and the conclusions are drawn as follows:1)The raft should be designed as a bending member in pile-raft structure.2)The increase in the thickness of the raft makes the stress down exponentially.3)The thickness of the cushion has a small effect on vertical stress of raft.4)The cushion in pile-raft structure plays a certain role in relieving the vertical stress concentration of raft.These provide a reference for pile-raft structure design and numerical simulation in the future.

关 键 词：高速铁路 桩筏结构 有限元 应力分析 筏板厚度 

分 类 号：U213.1[交通运输工程—道路与铁道工程]