脑畔梁滑坡土体及接触试样物理力学特性研究

Study on physical and mechanical properties of soil mass and contact sample of Naopanliang landslide

脑畔梁滑坡是由黄土和红黏土接触形成的“双层异质”接触型滑坡,研究黄土、红黏土以及黄土-红黏土接触试样的物理力学特性对脑畔梁滑坡治理工作具有一定借鉴意义。通过常规土工试验、激光粒度分析试验、核磁共振试验、崩解性试验和三轴压缩试验,查明了黄土和红黏土的物理力学性质;制备天然含水率和饱和含水率的黄土-红黏土接触试样,对其进行单轴压缩试验和三轴压缩实验,研究表明,天然含水率与高围压饱和含水率接触试样破坏方式为红黏土试样剪胀破坏,低围压饱和含水率则为黄土试样剪胀破坏;脑畔梁滑带埋深较深,受到围压较大,接触面处红黏土更易形成滑带,与勘查结果相同。本文从黄土、红黏土及黄土-红黏土接触试样的物理力学特性入手,初步探究了黄土-红黏土接触面滑坡的形成机理,为该类型滑坡的形成演化机理等研究提供了新的思路。

The Naopanliang landslide is a“two-layer heterogeneous”contact landslide formed by the contact of loess and red clay.Studying the physical and mechanical properties of loess,red clay and loess-red clay contact samples has certain reference significance for the treatment of Naopanliang landslide.The physical and mechanical properties of loess and red clay are obtained through conventional soil test,laser particle size analysis test,nuclear magnetic resonance test,disintegration test and triaxial compression test;The uniaxial compression test and triaxial compression test are carried out on the loess-red clay contact samples under natural water content and saturated water content.The results show that the failure mode of the contact samples with natural water content and high confining pressure saturated water content is the shear expansion failure of the red clay sample,and the low confining pressure saturated water content is the shear expansion failure of the loess sample;The Naopanliang slip zone is deeply buried and subjected to large confining pressure.The red clay at the contact surface is more likely to form a slip zone,which is the same as the survey results.Starting with the physical and mechanical properties of loess,red clay and loess-red clay contact samples,this paper preliminarily explores the formation mechanism of the loess-red clay contact surface landslide,providing a new idea for the study of the formation and evolution mechanism of this type of landslide.