摘要
高路堤承台式抗滑桩是一种可用于特殊条件下支挡高路堤的新型组合式抗滑结构,可适用于铁路沿线典型陡坡路堤工程,主要由上部的受荷桩板墙、中间的承台和下部的基础桩构成。为研究高路堤承台式抗滑桩在外荷载作用下桩侧土压力分布规律、内力与位移特征,依托云南弥勒至蒙自铁路某区段的典型高路堤工程,进行了几何、重度相似比分别为1∶13和1∶1的物理模型试验,并结合数值模拟及理论方法进行分析。结果表明:从桩-土系统变形发展与推力荷载关系而言,桩体水平位移随推力发展可分为较小推力作用下的线弹性小变形阶段、增长率缓慢增大的弹塑性变形阶段和增长率显著增大的塑性变形阶段共3个阶段;受荷桩板墙后侧土压力分布呈顶点位于中下部的抛物线模式;基础桩前侧和后侧土压力总体分别呈上小下大、上大下小的抛物线形分布,后侧土压力最大值位于基础桩顶端,后侧土压力合力占前侧的24%~37%;基础桩中部存在弯矩与剪力零点,其顶端弯矩、剪力较受荷桩底端显著减小,分别减小55%~60%、93%~94%;现行相关规范方法算得受荷桩、基础桩最大弯矩分别较试验值高出16%~36%、16%~23%,其算法显著偏保守;基础桩顶端弯矩较传统等截面抗滑桩减小56%~63%,意味着承台式抗滑桩可显著改善传统抗滑桩的“嵌固段”受力,整体上具有较为突出的力学性能优越性。
Stabilizing pile with rigid platform is a new type of composite stabilizing structure feasibly used to retain high embankment under special conditions,and particularly suitable for the typical embankments on steep terrains in railway engineering.It is mainly composed of upper loaded pile,middle rigid platform and lower inserted pile in the foundation.In order to reveal distribution mode of lateral earth pressure,internal force and displacement characteristics of the retaining structure under external loads,based on typical high embankments in Mile-Mengzi railway engineering in Yunnan province some model tests have been conducted with geometric and gravity similarity ratio of 1∶13 and 1∶1,respectively,and the related numerical simulation and theoretical method are jointly utilized to analyze the problem further.The results show that from the perspective of the relationship between the deformation development of pile-soil system and exerted thrust loads,the development of horizontal displacement of the retaining structure can be divided into three stages:small linear elastic deformation stage under low thrust,elastoplastic deformation stage with small increasing growth rate,and plastic deformation stage with significant increasing growth rate.Distribution curve of lateral earth pressure on the loaded pile-slab wall shows a parabolic pattern with a vertex at the middle-lower part.The earth pressure on the front and the back side of the inserted pile in the foundation generally presents parabolic distribution with small value at the top and big vale at the bottom,big value at the top and small value at the bottom,respectively.The maximum earth pressure on the back side of the inserted pile is located at its top,and the resultant force of the earth pressure on the back side accounts for 24% to 37% of that on the front side.There are zero bending moment and shear force in the middle of the inserted pile.Compared with internal forces at the bottom of the loaded pile,the bending moment and shear force at the top of the inserted pile are significantly reduced by 55% to 60% and 93% to 94%,respectively.The maximum bending moments of the loaded and inserted piles calculated by China railway specification are 16% to 36% and 16% to 23% higher than the experimental values,respectively,which suggests the proposed method in the specification is fairly conservative.Compared with the traditional stabilizing pile with invariable cross section,the bending moment at the top of the inserted pile is reduced by 56% to 63%,which indicates that the new retaining structure can greatly improve the mechanical state of the‘fixed segment’of the traditional stabilizing pile,and generally be of remarkable superiority in terms of mechanical performance.
作者
邓明园
杨泉
肖世国
李安洪
DENG Mingyuan;YANG Quan;XIAO Shiguo;LI Anhong(Department of Geological Engineering,Southwest Jiaotong University,611756 Chengdu,China;Key Laboratory of High-speed Railway Engineering,Ministry of Education,Southwest Jiaotong University,610031 Chengdu,China;China Railway Eryuan Engineering Group Co.,Ltd.,610031 Chengdu,China)
出处
《应用力学学报》
北大核心
2025年第1期182-193,共12页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金资助项目(No.51578466)
四川省交通运输科技项目(No.2020-A-01)
中铁二院工程集团有限责任公司科研项目(No.KSNQ202045)。
关键词
高路堤
承台式抗滑桩
力学行为
土压力
模型试验
high embankment
stabilizing pile with rigid platform
mechanical behavior
earth pressure
model test
作者简介
通信作者:肖世国,教授。E-mail:xiaoshiguo@swjtu.cn。
