摘要
为了更准确地预测主应力轴旋转条件下基坑开挖过程中的土体变形特性,采用有限元分析软件FLAC3D数值模拟地下连续墙典型支护形式下的基坑开挖过程,确定考虑主应力轴旋转的基坑开挖三维应力路径,并在此基础上采用空心圆柱扭剪仪开展一系列三维应力路径试验,探讨主应力轴旋转对基坑开挖过程中土体应变与非共轴性的影响。结果表明:在基坑开挖过程中,随着主应力轴旋转角的增加,坑内土体的应力-应变曲线上升越来越快,各正应变分量和切应变快速增大,应变逐渐增大;水平方向应变随着坑内测点与坑底表面中心距离的增加而缓慢增大且最终逐渐减小;非共轴性整体差别较小,初始有效应力与卸荷方式对非共轴性的影响较小;坑侧土体应力-应变曲线变化趋势基本保持平稳,各正应变分量和切应变从地表到坑底表面快速增大,达到屈服时的应变逐渐增大。
To predict soil deformation characteristics during foundation pit excavation under the condition of principal stress axis rotation more accurately,foundation pit excavation process with the typical support form of underground dia-phragm walls was numerically simulated by using finite element analysis software FLAC3D.Three-dimensional stress paths considering principal stress axis rotation were determined,and a series of three-dimensional stress path tests were conducted on the basis of this by using hollow cylinder torsional shear apparatus to investigate influences of principal stress axis rotation on soil strain and non-coaxiality during foundation pit excavation.The results show that as the prin-cipal stress axis rotation angle increases during foundation pit excavation,stress-strain curves of soil in pit show a faster upward trend,so do both normal strain components and shear strain,leading to gradual increase of strain.Horizontal strain increases gradually and eventually decreases with the increase of distance between observation points in pit and the center of pit bottom surface.Non-coaxiality shows relatively small differences,with no significant influence observed from initial effective stress and unloading method.The change trend of soil stress-strain curves remains stable along the side wall of pit,where increase of each normal strain component and shear strain accelerate from the ground surface to the pit bottom surface,and the strain reaching yield increases gradually.
作者
张亚宁
扈萍
高子茗
雍浩然
阮佳榆
ZHANG Yaning;HU Ping;GAO Ziming;YONG Haoran;RUAN Jiayu(School of Civil Engineering and Architecture,University of Jinan,Jinan 250022,Shandong,China;School of Civil Engineering,Heilongjiang University,Harbin 150080,Heilongjiang,China)
出处
《济南大学学报(自然科学版)》
北大核心
2025年第5期741-749,共9页
Journal of University of Jinan(Science and Technology)
基金
国家自然科学基金项目(51979122)。
关键词
基坑开挖
土体变形特性
三维应力路径试验
主应力轴旋转
非共轴性
foundation pit excavation
soil deformation characteristic
three-dimensional stress path test
principal stress axis rotation
non-coaxiality
作者简介
第一作者:张亚宁(2000-),女,山东日照人。硕士研究生,研究方向为土体本构理论与数值模拟。E-mail:19861825548@163.com;通信作者:扈萍(1980-),女,山东东营人。副教授,博士,硕士生导师,研究方向为岩土的本构理论与变形特性。E-mail:cea_hup@ujn.edu.cn。
