Mindlin方法在桩承式U形路基沉降分析中的应用  

Application of Mindlin Theory in Settlement Analysis of Pile Supported U-shaped Subgrade

作　　者：郭帅杰 宋绪国 GUO Shuaijie;SONG Xuguo(China Railway Design Corporation,Tianjin 300308,China;National-Local Joint Engineering Laboratory of Rail Transit Survey&Design,Tianjin 300308,China;National Engineering Laboratory for Digital Construction and Evaluation Technology of Urban Rail Transit,Tianjin 300308,China)

机构地区：[1]中国铁路设计集团有限公司,天津300308 [2]轨道交通勘察设计国家地方联合工程实验室,天津300308 [3]城市轨道交通数字化建设与测评技术国家工程实验室,天津300308

出　　处：《铁道标准设计》2023年第4期22-27,33,共7页Railway Standard Design

基　　金：中国铁路设计集团有限公司科技开发计划项目(2019YY222101,2020YY241004);2019-2021年度中国铁道学会青年人才托举工程项目(2019QNRC001)。

摘　　要：为解决桩承式悬臂U形路基的沉降分析问题,将Mindlin理论应用于桩承路基引起的地基附加应力分布与地基沉降变形计算。通过对复合地基、桩基两种承载方式的U形路基和放坡式路基地基深层附加应力以及沉降位移的对比分析,系统提出基于Mindlin点荷载附加应力叠加的桩承式U形路基沉降分析方法。分析结果表明:承载桩体桩侧摩阻同桩端阻的荷载分配应满足竖向力平衡条件,桩侧摩阻根据地层应为非线性分布;Mindlin理论能够满足桩承式U形路基的沉降计算需求,有效反映出桩体承载对加固区及桩端下卧层附加应力分布的影响;相同条件下,桩承式U形路基中心沉降分别为复合地基加固U形路基中心沉降量的22%和放坡式路基中心沉降量的15.4%,其在沉降位移控制方面优势突出。In order to analyze the settlement of pile supported cantilever U-shaped subgrade,Mindlin theory is applied to the calculation of additional stress distribution and settlement displacement.Based on the comparison of the additional stress as well as the settlement displacement of U-shaped and sloping subgrade with composite foundation or pile foundation,a newly developed method based on stress point load superposition is systematically proposed.The analysis results show that the load distribution between pile side friction and end resistance should satisfy vertical force balance condition,and the pile side friction must be in non-linear distribution according to the stratum.Mindlin theory can meet the settlement calculation requirements of pile supported U-shaped subgrade,and effectively reflect the influence on the additional stress distribution in the reinforcement and underlying layer.Moreover,under the same condition,the pile supported cantilever U-shaped subgrade has outstanding advantages in the foundation settlement control with 22% central settlement of the U-shaped subgrade reinforced by composite foundation and 15.4% of the sloping subgrade respectively.

关 键 词：U形路基 沉降分析 Mindlin理论 附加应力 结构形式 高速铁路 

分 类 号：TU433[建筑科学—岩土工程] U238[建筑科学—土工工程]