刚性墙后有限宽度土体被动滑裂面特征试验研究  

Experimental study on passive slip surface of limited width soil behind a rigid wall

作　　者：王崇宇[1,2] 刘晓平 张家强[1] 曹周红[1] WANG Chong-yu;LIU Xiao-ping;ZHANG Jia-qiang;CAO Zhou-hong(School of Hydraulic Engineering,Changsha University of Science and Technology,Changsha,Hunan 410114,China;Hunan Water Planning&Design Institute Co.,Ltd.,Changsha,Hunan 410008,China)

机构地区：[1]长沙理工大学水利工程学院,湖南长沙410114 [2]湖南省水务规划设计院有限公司,湖南长沙410008

出　　处：《岩土力学》2021年第7期1839-1849,1860,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51309037);湖南省重点实验室基金项目(No.2018DT04)。

摘　　要：利用无黏性粗砂开展刚性墙后有限宽度被动土体模型试验,采用高速相机监测了试验过程的土体变形图像,基于数字图像相关法对土体变形、剪切应变进行了分析,以揭示平动(T模式)、绕墙顶转动(RT模式)、绕墙底转动(RB模式)3种变位模式下土体滑裂面的特征。结果表明:有限被动宽度土体宽高比(B/H)界限值为T模式B/H≤2.0、RT模式B/H≤1.6、RB模式B/H≤1.1;T模式下,当1.6≤B/H≤2.0时,被动滑裂面由两个不连续的破裂面组成,下、上破裂面起点分别为移动挡墙墙踵、固定挡墙墙顶,当1.10≤B/H≤1.35时,滑裂面为一条曲面,两端点分别为移动挡墙墙踵、固定挡墙墙顶,当B/H≤0.75时,滑裂面为多条直线组成的"反射折线",由移动挡墙、固定挡墙为起点的滑裂线与水平夹角差别明显;RT模式下,被动滑裂面为移动挡墙墙踵后H/4点、固定挡墙墙顶两点形成的曲面;RB模式下,被动滑裂面以固定挡墙墙顶为起点,向移动挡墙墙身中部延伸,延伸点高度随B/H减少逐步抬高。A model experiment of passive soil with limited width behind a rigid retaining wall was carried out using non-cohesive coarse sand,with the soil images during the experiment collected through a high-speed camera.In addition,the soil deformation and shear strain were analyzed based on the digital image correlation method to reveal the slip surface characteristics in 3 movement modes:translational mode(T mode),rotate-about-top mode(RT mode),rotate-about-base mode(RB mode).The results show that:the boundary value of width to height ratio(B/H)of soil with finite passive width is,B/H≤2.0 for T mode,B/H≤1.6 for RT mode and B/H≤1.1 for RB mode.In T mode,when 1.6≤B/H≤2.0,the passive slip surface is composed of two discontinuous fracture surfaces,the lower and upper fracture surfaces start from the heel of the moving retaining wall and the top of the fixed retaining wall respectively;when 1.10≤B/H≤1.35,the slip surface is a curved surface,the starting point and the end point are the heel of the moving retaining wall and the top of the fixed retaining wall respectively;when B/H≤0.75,the slip surface is a"reflective broken line"composed of multiple straight lines,and the horizontal angle between the sliding line starting from the moving retaining wall and the fixed retaining wall is obviously different.In RT mode,the passive slip surface is a curved surface which passes through the H/4 point,the heel of the moving retaining wall and the top of the fixed retaining wall;in RB mode,the passive slip surface starts from the top of the fixed retaining wall and extends to the middle of the moving retaining wall,and the height of extension point gradually increases with the decrease of B/H.

关 键 词：模型试验 有限宽度土体 被动土体 不同变位模式 滑裂面 无黏性粗砂 

分 类 号：TU432[建筑科学—岩土工程]