非饱和黄土的结构屈服特性及主要影响因素  

Structural yielding characteristics of unsaturated loess and main influencing factors

作　　者：闫亚景[1] 文宝萍[1] 

机构地区：[1]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《水文地质工程地质》2013年第3期63-68,共6页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目资助(40872182)

摘　　要：本文以兰州黄土为对象,基于三轴试验,探讨了非饱和黄土的结构屈服特征及主要影响因素。研究发现,非饱和黄土的剪切破坏性状随饱和度、干密度不同,密度较大黄土具有应变软化行为,反之呈现应变硬化特性;前者在饱和度70%时,其剪切行为显著转变。黄土的结构屈服特性随饱和度增加逐渐弱化,其中密度较高和密度较低黄土的结构屈服应力分别呈非线性及线性降低;另一方面,随围压、干密度和粘粒含量增加,不同饱和度黄土的结构屈服特性逐渐增强。密度较高和较低黄土的结构屈服应力与围压分别非线性、线性正相关关系,随干密度增大非线性增加。In this paper,the variation in structural yielding characteristic of the loess from Lanzhou city and the main affecting factors were analyzed via triaxial test.The results show that shear behavior of the unsaturated loess varied with degree of saturation,dry density and confining pressure.The loess with higher dry densities was of strain-softening behavior,while those with lower dry densities had strain-hardening nature.For the former,its shear behavior changed at saturation degree of 70%.The structural yielding characteristics were weakened with increase in saturation degree,with which structural yielding stress for the loess with higher and lower dry densities decreased nonlinearly and linearly.On the other hand,structural yielding characteristics of loess with different saturation degree were strengthened with the increase in confining pressure,dry density and clay content.Particularly,the structural yielding stress of the loess with higher and lower dry densities had nonlinear and linear correlations with confining pressure respectively,and increased nonlinearly with dry density.

关 键 词：非饱和黄土 结构屈服应力 饱和度 围压 粘粒含量 

分 类 号：TU444[建筑科学—岩土工程]