列车长持时振动引起黄土滑坡微结构变化研究  

Research on the micro-structure change in the slide-zone soil in loess landslide caused by train-induced long-term vibration

作　　者：任权[1,2] 王家鼎[1] 谷天峰[1] 高建勋[2] 

机构地区：[1]西北大学地质学系/大陆动力学国家重点实验室,陕西西安710069 [2]陕西省交通规划设计研究院,陕西西安710068

出　　处：《水文地质工程地质》2013年第4期117-120,共4页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金资助项目(40572157)

摘　　要：通过研究不同试验条件下黄土滑坡滑带土孔隙定向性的变化特征,研究列车振动对黄土滑坡产生的诱发作用。结果表明:滑带黄土承受动荷载作用后,结构发生明显变化,孔隙破碎严重,其结构形态从圆形或椭圆形向长条形变化且呈一定的定向性,从而造成土体压密。在此基础之上,提出一种列车长持时振动荷载下的黄土滑坡形成机理。Based on numerous dynamic triaxial and SEM tests,this paper examines the characteristic changes in porosity micro-structure of loess slide-zone soil under the dynamic load.The results show that under the dynamic triaxial test,the structure of the samples become more compact and stable,and loess pore breaks up and show the characteristics of orientation.Based on the results,the mechanism of loess landslide induced by long-term vibration is presented,following minor amplitude and long-term vibration—Micro-structure changed—among soil particles cemented weakened—seismic subsidence of loess—soil shear strength reduction—state of stress changed—shear failure produced in slope toe—shear stress adjustment—shear failure produced in slope(continuous cycle)—slip surface produced—loess landslide.

关 键 词：黄土滑坡 振动荷载 孔隙结构 机理 

分 类 号：P642.131[天文地球—工程地质学]