水敏性黄土的湿剪试验研究  

Wet shear tests on structural loess

作　　者：李鹏[1,2,3] 胡再强 焦黎杰[1] 田春亮[1] 

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048 [2]陕西省黄土力学与工程重点实验室,陕西西安710048 [3]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《岩土工程学报》2010年第9期1434-1438,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50778152)

摘　　要：应用改制的应力式直接剪切仪,首先对不同剪应力水平作用下原状黄土浸水饱和湿剪演化规律进行了研究;其次选取了一个剪应力水平对不同增湿浸水量作用下原状黄土和扰动黄土湿剪演化规律进行了进一步探索,并在此基础上定义了黄土水敏性结构参数mω。结果表明,黄土在湿剪过程中剪位移随时间变化曲线可以分为两个阶段:湿剪迅速发展阶段和湿剪稳定阶段;浸水饱和增湿后试样抗剪强度值受剪应力水平影响较小,竖向变形以增湿湿陷变形为主;而其水敏性结构参数在低固结压力、低含水率条件下对水的敏感性较强,在高固结压力、高含水率条件下对水的敏感性较小。A modified direct shear stress instrument is employed to study wet shear evolution of saturated loess under different levels of shear stress.The wet shear evolution rules of undisturbed and disturbed loess are further discussed under different humidifying water volumes according to a certain level of shear stress.On such a basis,a structural parameter of loess mω is defined.The results show that during the wetting process of loess,the curves of shear displacement over time can be divided into two stages： rapid development stage and stability shear stage.The shear stress has small impact on the shear strength of the saturated loess samples,and the vertical deformation is mainly the collapsible one.The structural parameter exhibits strong sensitivity to water under low consolidation pressure and low water content,and weak sensitivity to water under high consolidation pressure and high water content.

关 键 词：结构性黄土 湿剪 不同增湿量 水敏性结构参数 

分 类 号：TU444[建筑科学—岩土工程]