平面应变下原状黄土的剪切带研究  

Study on shear bands of undisturbed loess under plane strain

作　　者：赵凯[1] 邵帅[1,2] 邵生俊[1,2] 魏军政[3] 张少英[1] 张玉 ZHAO Kai;SHAO Shuai;SHAO Sheng-jun;WEI Jun-zheng;ZHANG Shao-ying;ZHANG Yu(Institute of Geotechnical Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China;Shaanxi Key Laboratory of Loess Mechanics and Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an,Shaanxi 710043,China;Civil and Architecture Engineering,Xi’an Technological University,Xi’an,Shaanxi 710021,China)

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048 [2]西安理工大学陕西省黄土力学与工程重点实验室,陕西西安710048 [3]中铁第一勘察设计院集团有限公司,陕西西安710043 [4]西安工业大学建筑工程学院,陕西西安710021

出　　处：《岩土力学》2023年第2期433-441,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52108342);陕西省自然科学基础研究计划-引汉济渭联合基金项目(No.2019JLP-21,No.2019JLZ-13);西安理工大学博士启动金(No.107-451122001);陕西省水利科技计划项目(No.432021019)。

摘　　要：针对黄土地区工程建设中的平面应变问题,使用改进的西安理工大学真三轴仪进行了不同侧向固结压力、不同含水率下原状黄土的平面应变剪切试验,得出了剪切破坏时剪切带倾角试验值,根据应力-应变关系曲线求出了剪切带倾角的Mohr-Coulomb、Roscoe理论解,分析了相应控制因素下原状黄土强度、剪切带破坏模式与倾角的变化。结果表明:应力-应变曲线随含水率、侧向固结压力的增大从原生软化型向次生硬化型转变;剪切带破坏模式随侧向固结压力的增大依次呈现单一剪切带、锥型剪切带和X型剪切带;随着含水率的增大,黏聚力、内摩擦角减小导致Mohr-Coulomb剪切带倾角减小,剪胀作用增强导致Roscoe剪切带倾角增大;随侧向固结压力增大,动内摩擦角增大及剪胀作用增强,导致Mohr-Coulomb、Roscoe剪切带倾角增大。For the plane strain problem of engineering construction in loess area,the plane strain shear tests on intact loess under different lateral consolidation pressures and moisture contents were carried out by using the transformational true triaxial apparatus of Xi’an University of Technology.The experimental measurements of angle of inclination for shear band at shear failure were obtained.The Mohr-Coulomb and Roscoe solutions to angle of inclination for shear band of were derived from the stress-strain curve.The changes of intact loess strength,failure mode and angle of inclination for shear band were analyzed.The study results show that the stress-strain curve vary from primary softening type to secondary hardening type wih the development of new structure when the water content and lateral consolidation pressure increase.The failure modes of shear band present single line-shaped,cone-shaped and X-shaped as the increase of lateral consolidation pressure.Along wih the increase of moisture content,decrease in the cohesion,internal friction angle leads to reduce the angle of inclination for shear band of Mohr-coulomb solution,while the enhanced dilatancy rising the Roscoe solution.With the increase of lateral consolidation pressure,both the dynamic internal friction angle and the dilatancy are increase,resulting in shear band inclination angles of Mohr-Coulomb and Roscoe solution increase.

关 键 词：平面应变试验 黄土 应力-应变关系 Mohr-Coulomb剪切带 Roscoe剪切带 

分 类 号：TU444[建筑科学—岩土工程]