红黏土在原状及重塑状态下的力学性质试验研究

土的结构性是土中颗粒或颗粒集合体及孔隙之间的大小、形状、排列组合及联结等综合特征。不同围压下固结不排水三轴压缩试验表明,贵阳原状和重塑红黏土应力应变曲线、有效应力路径、抗剪强度指标、破坏形态等宏观力学行为明显不同。考虑红黏土结构性,通过SEM电镜扫描测试,指出红黏土矿物颗粒单元间接触和联结状态,对比分析原状和重塑土样在颗粒形态、孔隙结构与分布等微观差异,研究结构性红黏土宏观强度与变形特性的细微观机理。研究成果对于正确认识红黏土的结构性具有重要作用,可为结构性红黏土工程设计与施工提供理论依据和技术指导。

Experimental Study on Undisturbed and Reconstituted Mechanical Properties of Red Clay

Soil structural is the comprehensive characteristics of size,shape,arrangement and connection between particles,aggregates,and corresponding pore system in soil.The results undrained triaxial test under different confining pressure shown that the Macro-mechanical behaviors of stress-strain curve,effective stress path,shear strength index and failure mode of Guiyang undisturbed and reconstituted red clay were obviously different.Considering the structure properties of red clay,the contact and coupling state of the red clay mineral particles were analyzed by scanning electron microscopy (SEM),the micro mechanism of macroscopic strength and deformation characteristics of structural red clay was studied through comparative analysis the microscopic differences of particle morphology,pore structure and distribution for undisturbed and reconstituted red clay.The research results play an important role in understanding the structural of red clay correctly,and provide a theoretical basis and technical guidance for engineering design and construction in structural red clay region.