位于巫溪县的南门湾危岩带曾发生多次破坏，共造成百余人死亡，严重制约了当地的社会经济发展。在前人研究成果的基础上，选择危岩带中4个滑移式危岩体为研究对象，根据蒙特卡洛模拟法计算出它们在天然和暴雨工况下的破坏概率，并结合实际情况分析了危岩体的威胁对象及其易损性，最后根据以上数据计算得出：自然工况下人员伤亡风险为0.30人，经济损失风险为15.16万元；暴雨工况下人员伤亡风险为0.65人，经济损失风险为31.91万元。评价结果可为防灾减灾服务。

Located in Wuxi county, Nanmenwan dangerous rock zone has encountered failure for many times which caused deaths of more than 100 people and restricted local social and economic development. On the basis of previous researches, four sliding dangerous rock masses from the zone were chosen as research objects, and their failure probability in normal and rainstorm conditions were calculated by Monte Carlo simulation. The element at risk of the rock masses as well as their vulnerability were also analyzed based on the actual situation. Finally, according to the computation of the above data, the authors concluded that under normal condition, the casualty risk was 0.30 person, and the economic loss risk was 151,600 yuan；while under rainstorm condition, the casualty risk was 0.65 person, and the economic loss risk was 319,100 yuan. Risk assessment results can be used as reference for disaster prevention and reduction.