主应力方向诱导风积土各向异性强度准则及试验验证  

Anisotropic strength criterion of aeolian soil under stress path considering the variation of principal stress direction

作　　者：刘家顺[1,2,3] 朱开新 蔡燕燕 任钰[1] 生彦涛 刘页龙 LIU Jiashun;ZHU Kaixin;CAI Yanyan;REN Yu;SHENG Yantao;LIU Yelong(College of Civil Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210046,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Fujian Research Center for Tunneling and Urban Underground Space Engineering,Huaqiao University,Xiamen,Fujian 361021,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210046 [3]中国矿业大学(北京)力学与建筑工程学院,北京100083 [4]华侨大学福建省隧道与城市地下空间工程技术研究中心,福建厦门361021

出　　处：《岩石力学与工程学报》2023年第7期1789-1798,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52104088);河海大学岩土力学与堤坝工程教育部重点实验室项目(2020007);辽宁省教育厅科学研究经费项目(面上项目)(LJKZ0361)。

摘　　要：为探究岩土材料的各向异性与应力方向性力学行为,以辽西风积土为研究对象,利用空心圆柱扭剪仪(GDS-SSHCA)开展主应力方向角分别为0°,15°,22.5°,30°,45°,60°,67.5°,75°和90°的定向剪切试验,研究不同大主应力方向作用时风积土剪应力–剪应变曲线变化规律和各向异性强度特征。试验结果表明:当α≤30°时,土体的剪切强度随着α的增大而增大;当α>30°时,土体的剪切强度随着α的增大而减小。不同大主应力方向定向剪切时风积土试样强度存在显著的各向异性。在试验结果的基础上,基于等效应力思路,采用组构–应力坐标变换,综合考虑应力、组构的大小及应力–组构的方向关系,建立风积土的等效修正各向异性Lade-Duncan准则(EL-D准则)并利用定向剪切试验结果验证所建立的各向异性准则的可靠性。结果表明,所建立的EL-D准则可以较好的描述应力诱导的风积土各向异性强度特征。研究成果可为岩土材料各向异性研究和风积土工程灾害防治提供科学支撑。To investigate the anisotropy and stress directional mechanical behavior of geotechnical materials,directional shear tests of aeolian soil with principal stress direction angles of 0°,15°,22.5°,30°,45°,60°,67.5°,75°,and 90°were performed using a hollow cylinder torsion shear apparatus(GDS-SSHCA).The variation law of the shear stress-shear strain curve and anisotropic strength characteristics of aeolian soil under the action of different major principal stress directions are presented.Test results shown that when α≤30°,the shear strength of soil increases with the increase of α;when α>30°,the shear strength of soil decreases with the increase ofa.Significant anisotropy exists in the strength of aeolian soil samples under directional shearing in different major principal stress directions.Based on the test results,the equivalent modified anisotropic Lade-Duncan criterion(EL-D criterion)of aeolian soil is established by using the fabric-stress coordinate transformation based on the idea of equivalent stress and considering the stress,the size of the fabric,and the direct relationship between the stress and the fabric.The reliability of the established anisotropic criterion is verified by the directional shear test results of aeolian soil.The results show that EL-D criterion established in this paper can better describe the strength characteristics of stress-induced anisotropy in aeolian soil.The research results will provide scientific support for the study of anisotropy of geotechnical materials and the prevention and control of aeolian soil engineering disasters.

关 键 词：土力学 主应力方向 风积土 各向异性 等效应力 

分 类 号：TU43[建筑科学—岩土工程]