滑坡运动距离超越概率评价及危险性区划  

Assessment of exceedance probability of landslide run-out distance and hazard zoning

作　　者：孙小平 曾鹏 张天龙 王升 SUN Xiaoping;ZENG Peng;ZHANG Tianlong;WANG Sheng(College of Environmental and Civil Engineering,Chengdu University of Technology,Chengdu 610059,Sichuan,China;State Key Laboratory of Geo-hazard Prevention and Geo-environment Protection,Chengdu 610059,Sichuan,China)

机构地区：[1]成都理工大学环境与土木工程学院,四川成都610059 [2]地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《地质通报》2021年第9期1560-1569,共10页Geological Bulletin of China

基　　金：国家自然科学基金项目《土质滑坡冲击强度超越概率定量评价方法研究》(批准号:41977224);国家自然科学基金青年基金项目《基于稀疏随机响应面法的单体滑坡系统失稳概率定量评估》(批准号:41602304);四川省科技计划《基于自适应克里金方法的三维单体滑坡系统风险定量评估研究》(编号:2019YJ0405)。

摘　　要：针对岩土体物理力学参数不确定性强、动态数值模拟方法对滑坡运动距离预测精度有限的问题,提出一种基于拉丁超立方采样法(LHS)的滑坡运动距离超越概率定量评价方法,以提高滑坡滑程预测结果的可靠性。该方法将滑坡计算参数考虑为服从某种概率分布的随机变量,使用LHS对随机变量进行分层抽样,并基于动态数值模型计算每组随机样本对应的滑坡运动距离,最后,通过构建不同运动距离阈值下的极限状态函数计算运动距离超越某一给定位置的概率。应用该方法对大堡子滑坡运动距离进行评价,得到该滑坡运动距离在95%置信水平下的置信区间为[196 m,302 m];并根据运动距离-超越概率图,提出以50%、10%、1%和0.1%作为分界概率值将该滑坡潜在威胁范围分为极高、高、中、低、极低5个危险性等级。计算结果显示,滑坡实际运动距离在95%置信区间内,实际的威胁范围也在划分的高-极高危险区内,说明评价结果合理,证明了基于运动距离超越概率的滑坡运动危险性评价的有效性。研究成果为滑坡运动距离评价及危险性区划提供了新的思路,具有重要的理论意义和工程实用价值。In view of the large uncertainties embedded in the physical and mechanical parameters of the dynamic numerical model,a quantitative method to assess exceedance probability of landslide run-out distance based on Latin Hypercube Sampling(LHS)is proposed to improve the reliability of landslide slide prediction results.In the proposed method,the input parameters are considered as random variables with probability distribution functions;the LHS is used to generate stratified samplings for the random variables,and the dynamic numerical model is used to compute the landslide run-out distance corresponding to each random sample;and finally,the exceedance probability of landslide run-out distance is calculated by constructing limit state functions for different run-out distance threshold values.The proposed method is applied to conduct a probabilistic assessment of the run-out distance for Dabaozi landslide,and the 95%confidence interval of the run-out distance is computed as[196 m,302 m].According to the run-out distance-exceedance probability curve,the potential affected area of the landslide is classified into five categories(i.e.,extremely high,high,medium,low and extremely low)based on different threshold values of exceedance probability(i.e.,50%,10%,1%and 0.1%).The calculation results show that the actual run-out distance of landslide is within the 95%confidence interval,and the actual threat range is also within the classified high-extremely high danger zone.The results show that the evaluation results are reasonable and the landslide movement risk evaluation based on the distance exceeding probability is also proved effective.The proposed method may provide new ideas for landslide run-out distance assessment and for hazard zoning,which has important theoretical significance and practical engineering value.

关 键 词：滑坡运动距离 动态数值模型 LHS 超越概率 危险性区划 

分 类 号：P694[天文地球—地质学] P642.22