原状黄土的结构强度变形特性分析

研究目的：在试验的基础上，分析原状黄土微结构性状及黄土的强度变形特性与黄土微结构的内在联系。 研究方法：采用扫描电镜图象分析及室内静三轴剪切试验的方法，对Q3、Q2原状黄土的结构性状及强度变形特性。研究结果：黄土的结构特性随着埋藏深度的增加，由支架大孔微胶结结构逐渐变为镶嵌微孔半胶结结构，支架大孔孔隙发育变为粒间孔隙发育，再为微孔孔隙发育。黄土的结构性是控制其强度变形特性最为重要的因素之一，上层Q3黄土的结构可稳性较大，可变性较小，在受荷过程中其应力应变曲线表现为较明显的变形软化性质；随着埋藏深度的及围压的增加，下层Q2黄土的结构可变性逐渐变大，而可稳性变小，在受荷过程中其应力应变曲线表现出较明显的变形硬化特性。 研究结论：黄土的强度变形特性是黄土结构可稳性和可变性的综合反映，和黄土颗粒的连接特性及排列特性相关。

Analysis of Structural Strength and Deformation Properties of Intact Loess

Research purposes: Based on the testing,this paper analyzes the microstructure properties of intact loess and the internal logic of the characteristics of strength and deformation with microstructure of intact loess.Research methods:Adopted the scanning electron microscopy(SEM) of microstructure and static triaxial shear tests of intact loess,this paper analyzes the microstructure feature and the characteristics of strength and deformation of Q3,Q2 intact loess.Research results:With the increasing of embedding depth,the microstructure feature of intact loess changed gradually from the bracketed-macropore weak-cemented texture to the inlaid-micropore half-cemented texture,the void properties changed from bracketed-macropore void to void among grains,then to micropore void.The microstructure feature of loess was one of important factors which dominated the characteristics of the strength and deformation of loess,upper Q3 loess layers,with greater stabilizability of microstructure than changeability,the curves types of stress-strain of loess in the process of loading appeared as the softening obviously deformation properties.With the increasing of embedding depth and confining pressures,the stabilizability of the microstructure of lower Q2 loess layers was less than its changeability,and the curves types of stress-strain of loess in the process of loading put up the hardening observably deformation properties.Research conclusions:The characteristics of the strength and deformation of intact loess were the comprehensive effect of the stabilizability and changeability of microstructure of loess,which correlated closely to the characteristics of linked and tactic of loess grains.