基于边坡单元的公路沿线滑坡危险度概率分析

公路沿线发生的滑坡、泥石流等自然灾害是造成交通停滞的主要原因。对公路沿线边坡进行稳定性评价及滑坡灾害分析对于公路管理和灾害防治具有重要意义。为了能对大范围边坡应用三维力学模型进行稳定性评价，研究中将较大研究区域划分为多个边坡单元（slope unit），并介绍了边坡单元划分方法。对每个边坡单元，采用随机生成许多假想滑动面并通过一个基于GIS的边坡稳定性三维分析模型计算其安全系数的方法，找出具有最小安全系数的危险滑动面，同时求出在试算过程中安全系数小于某临界值（通常设为1.0）的结果出现的比率，作为该边坡单元的滑坡发生概率，以此作为指标对研究区域进行危险度评价。通过对日本49号国道沿线边坡中的应用对该方法的实用性进行了验证。

Slope unit based probabilistic analysis of slope stability along highway routes in Japan

Landslides, that occurred on steep slopes along highway routes, always cause traffic stagnation, even endanger property and human life. For doing maintenance work effectively and avoiding disaster, it is essential to assess stability of road slopes. In this study, the large research area is firstly divided into slope units, which are used as the objectives of the three-dimensional deterministic model. Then a random searching method is used to locate the critical slip surface of each slope unit. The critical slip surface with the minimum safety factor is calculated by a GIS-based 3D slope stability model. The failure probability of each slope unit is calculated and landslide hazard degree of the studied area is zoned quantitatively. The methodology is illustrated by a probabilistic slope analysis of the 49th national road in Gouto area of Japan.