中文摘要：

采用有限差分软件FLAC3D对黄土高原坡沟系统重力侵蚀机理进行探索,对坡沟系统应力场和位移场进行数值模拟,分析了不同侵蚀基准面抬升高度对坡沟稳定性及重力侵蚀的影响。结果表明,随侵蚀基准面逐渐抬升,坡沟系统逐渐稳定,最大位移、安全系数及滑塌概率的变化符合指数函数分布规律。拟合方程精度较高,可应用于坡沟重力侵蚀的定性分析与定量计算。凹形边坡整体几何形态能够有效降低应力集中,减缓重力侵蚀的发生程度;坡沟系统上部位移是以＂沉降＂模式为主,梁峁顶和梁峁坡是重力侵蚀最为强烈的部位。随侵蚀基准面逐渐抬升,各方向位移均有不同程度降低。

英文摘要：

Mechanism of gravitational erosion in the slope-gully system of the Loess Plateau was explored with the aid of the finite difference software,Flac3D,while numerical simulation of stress field and displacement field of the system and analysis of effect of rising elevation of the erosion base level on slope-gully stability and gravitational erosion was performed.Results show that the slope-gully system tends to stabilize with the rising elevation of the erosion base level;its maximum displacement,safety factor and landslide probability vary within the exponential function distribution range.Its fitting equation is high enough in accuracy to be used in qualitative and quantitative analysis of gravitational erosion of the system.The geometric shape of concave slope can effectively reduce stress concentration,mitigate the likelihood of gravitational erosion,The displacement in the upper part of the slope-gully system appears mainly in the form of ＂settlement＂,tops and slopes of barren hills are the most susceptible to gravitational erosion;with rising elevation of the erosion base level,displacement to whatever direction is decreased to a various degree.