旱区陡坡黄土的低压力抗剪强度特性试验研究  

Experimental study on low pressure shear strength characteristics of steep slope loess in arid region

作　　者：邱明明 田宇轩 孙杰龙 杨红霞[1] 郑隆君 周恒祎 李明泽 QIU Mingming;TIAN Yuxuan;SUN Jieong;YANG Hongxia;ZHENG Longjun;ZHOU Hengyi;LI Mingze(School of Civil Engineering,Yan’an University,Yan’an 716000,China)

机构地区：[1]延安大学建筑工程学院,陕西延安716000

出　　处：《延安大学学报（自然科学版）》2023年第1期39-45,共7页Journal of Yan'an University：Natural Science Edition

基　　金：陕西省教育厅服务地方专项计划项目(21JC035);延安市重点研发计划项目(2019ZCSY-006);延安大学科研计划项目(CXY202006,YDY2020-36);大学生创新创业训练计划项目(202110719036)。

摘　　要：黄土强度指标的准确确定是地质体稳定性分析的基础依据。以延安地区某边坡上更新统黄土为研究对象,利用改进的直剪仪,开展不同初始含水率、密度、干湿循环条件下原状与重塑黄土的低压力抗剪强度试验,研究原状与重塑黄土的低压力抗剪强度及抗剪强度指标随初始含水率、密度及干湿循环次数的变化规律,建立黄土的低压力抗剪强度指标与初始含水率、密度及干湿循环次数之间的函数关系。结果表明,黄土的低压力抗剪强度与初始含水率的关系可采用指数函数描述,与土体密度和干湿循环次数的变化关系可采用线性函数描述;原状与重塑黄土的黏聚力、内摩擦角与初始含水率之间呈负相关,且原状黄土抗剪强度指标高于重塑黄土;黄土的抗剪强度指标随土体密度增加而显著提高,随干湿循环次数增加呈明显减小趋势。The accurate identification of loess strength index is the basis of geological stability analysis.The pleistocene loess on a slope in Yan’an was taken as the research object,the low pressure shear strength of undisturbed and remolded loess under the different initial water content,density and wetting-drying cycle condi⁃tions was tested by the improved direct shear apparatus.The variation rules of low pressure shear strength and shear strength indexes of undisturbed and remolded loess with initial water content,density and the times of wetting-drying cycles were studied,and the functional relationship between the low pressure shear strength indexes of loess and the initial water content,density and the times of wetting-drying cycles was established.The research results show that the relationship between low pressure shear strength and initial water content of loess can be described by exponential function,and the relationship between low pressure shear strength and soil density and the times of wetting-drying cycles can be described by linear function.The cohesion,internal friction angle and initial water content of undisturbed and remolded loess are negatively correlated,and the shear strength indexes of undisturbed loess is higher than that of remolded loess.The shear strength indexes of loess increased significantly with the increase of soil density and decreased significantly with the increase of the times of wetting-drying cycle.

关 键 词：黄土 低压力 干湿循环 抗剪强度 黏聚力 内摩擦角 

分 类 号：TU444[建筑科学—岩土工程]