低应力作用下含水率对云南蒙自膨胀土抗剪强度的影响研究  

STUDY ON THE IMPACT OF MOISTURE CONTENT ON THE SHEAR STRENGTH OF MENGZI EXPANSIVE SOIL IN YUNNAN UNDER LOW STRESS

作　　者：李清滢 陈颖辉[1] 欧明喜[1] 赵雨 LI Qing-ying;CHEN Ying-hui;OU Ming-xi;ZHAO Yu(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,650500,Kunming,China;China Construction Transportation Construction Group Co.,Ltd.,100071,Beijing,China)

机构地区：[1]昆明理工大学建筑工程学院,昆明650500 [2]中建交通建设集团有限公司,北京100071

出　　处：《建筑技术》2023年第22期2772-2776,共5页Architecture Technology

摘　　要：为研究低应力作用下含水率对云南蒙自膨胀土抗剪强度特性的影响,对不同初始含水率的重塑膨胀土进行常规快剪试验。试验发现:在低应力作用下,含水率对蒙自膨胀土抗剪强度影响显著,随着含水率的增大,土体的抗剪强度减小,内摩擦角和粘聚力减小,且含水率与抗剪强度及其指标之间存在非线性关系。根据试验结果,首先采用3种非线性拟合方法建立含水率与抗剪强度之间的关系式,然后通过计算相关系数及残差平方和对3种拟合方法进行分析比较,最后得到基于Mnoh-Coulumb强度理论的研究方法拟合效果最好,多元非线性拟合分析的效果最差。因此选用基于Mnoh-Coulumb强度理论建立的强度关系式能较好地表达蒙自膨胀土在低应力作用下含水率与抗剪强度之间的关系,也为云南蒙自膨胀土的强度特性提供了参考和理论依据。In order to study the impact of moisture content on the shear strength of Mengzi expansive soil in Yunnan under low stress,conventional regular shear tests were carried out to expansive soil with different initial moisture contents.According to the test results:the moisture content has significant impact on the shear strength of Mengzi expansive soil under low press.As the moisture content rises,the shear strength of soil decreases,so does the internal friction angle and cohesion.In addition,the moisture content has a nonlinear relationship with the shear strength and other indexes.Based on the test results,the relationship between the moisture content and shear strength was first established by three nonlinear fitting methods.Then,these three fitting methods were analyzed and compared by calculating the correlation coefficient and residual sum of squares.Results show that the research method based on Mnoh-Coulumb strength theory had the best fitting effect,while the multivariate nonlinear fitting analysis had the worst fitting effect.Therefore,the strength relation formula based on Mnoh-Coulumb strength theory can better express the relationship between the moisture content and shear strength of Mengzi expansive soil under low stress.It also provides a reference and theoretical basis in terms of the strength of Mengzi expansive soil in Yunnan.

关 键 词：蒙自膨胀土 低应力 抗剪强度 含水率 非线性 

分 类 号：TU4[建筑科学—土工工程]