中文摘要：

随着黄土地区高速铁路的兴建,为了能更好地服务于该地区高速铁路沿线黄土滑坡的防治工作,本文通过室内不排水动三轴试验,研究了黄土在高速列车这种＂长持时,小振幅＂荷载作用下的动力特性。试验结果表明,黄土在列车循环荷载作用下其动强度随着振动次数的增加而降低,且黄土在振动过程大多会发生振陷。由扫描电镜试验可知黄土发生振陷主要是由于土体中的大颗粒被振碎,大、中孔隙减少,土体不断被压密所致。在此基础上,提出了循环荷载诱发黄土滑坡的形成机理,并首次将熵增理论应用到黄土滑坡形成机理的解释中,取得了较为满意的结果,为高速铁路沿线黄土滑坡的防治提供了新的理论依据。

英文摘要：

With the development of high-speed rail,dynamic characteristics of loess are studied under ‘minor amplitude and long-term’vibration induced by high-speed train through Undrained Compression Test in order to better serve the prevention and treatment of loess landslide along the high-speed rail in the loess region.The results indicate that dynamic strength of loess reduces with the number of vibration increase under cyclic loading of the train,and dynamic subsidence occurrs in the loess during the vibration.Known by the SEM,loess dynamic subsidence is mainly due to large particles being broken by vibration,large or medium porosity being reduced,and soil being compacted constantly.Based on it,the mechanism of loess landslide induced by cyclic load is presented and obtained by applying the principle of entropy increase to explain the mechanism of loess landslide at the first time.It will provide a new theory basis for the loess landslide prevention along the high-speed rail.