基于NSGA-Ⅱ遗传算法的黄土滑坡参数反分析与稳定性预测  

Parameter Back Analysis and Stability Prediction of Loess Landslide Based on NSGA-II Genetic Algorithm

作　　者：曾鹏 王宇豪 张天龙 张琳 南骁聪[5] Zeng Peng;Wang Yuhao;Zhang Tianlong;Zhang Lin;Nan Xiaocong(College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Sichuan Chuanjian Survey and Design Institute Co.Ltd.,Chengdu 610094,China;Shandong High‐Speed Engineering Detection Co.Ltd.,Jinan 250002,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]成都理工大学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 [3]西南交通大学土木工程学院,四川成都610031 [4]四川省川建勘察设计院有限公司,四川成都610094 [5]山东高速工程检测有限公司,山东济南250002

出　　处：《地球科学》2023年第5期1675-1685,共11页Earth Science

基　　金：国家自然科学基金项目(No.41977224).

摘　　要：甘肃省永靖县黑方台台塬周边区域由于黄河移民大规模农业灌溉诱发了众多黄土滑坡灾害,其稳定性分析与滑面预测可为防灾减灾提供重要支撑,显得尤为重要.黑方台黄土滑坡具有渐进后退式的失稳特征,已发生滑坡灾害与潜在滑坡灾害具有高度相似性,其反分析结果可为未来滑坡稳定性分析提供重要数据基础.选用有限差分强度折减法,通过设定3个目标优化函数(土体抗剪强度参数均值误差函数、滑面位置误差函数和稳定性系数误差函数),基于NSGA-Ⅱ遗传算法开展稳定性反分析获取黄土的粘聚力和内摩擦角.以黑方台党川2#滑坡为例,通过第一次滑动时观测到的滑面信息,并假设其稳定性系数等于1,利用NSGA-Ⅱ算法反分析得出当滑坡发生时,天然黄土层粘聚力为28.20 kPa,内摩擦角为25.16°,饱和黄土层有效粘聚力为16.59 kPa,有效内摩擦角为16.11°.基于该反分析结果,对党川2#滑坡后续3次失稳的稳定性系数和临界滑面进行了预测,并与实际观察结果对比验证.研究结果表明,通过多目标约束优化算法开展滑坡稳定性反分析可获得更加合理的黄土强度参数估计,为黑方台地区滑坡稳定性分析和风险定量评估提供了新的解决思路.Many loess landslides were caused by the agricultural irrigation in Heifangtai terrace,Yongjing County,Gansu Province.Their stability analysis and critical slip surface identification are particularly important,as it can provide a good support to disaster prevention.The loess landslides located on the margin of Heifangtai terrace have the characteristics of progressive backward failure,and the occurred and potential landslides are highly similar.The results from back analysis can provide important data basis for future landslide stability prediction.In this paper,the finite difference strength reduction method was used to calibrate the cohesion and internal friction angle of loess based on the NSGA-II genetic algorithm by setting three objective optimization functions(i.e.,mean value of soil strength parameters,slip surface and factor of safety).Taking Dangchuan 2#landslide in Heifangtai terrace as a study case,based on the slip surface observed after the first slide and assuming its factor of safety was equal to 1,the back analysis results show that the cohesion and internal friction angle of natural loess were 28.20 kPa and 25.16°;and the effective cohesion and internal friction angle of saturated loess were 16.59 kPa and 16.11°.Based on the computed results,the factor of safety and critical slip surface of the three subsequent slides were predicted,with their comparison with in-site observation information.The results show that a more reasonable estimation of loess strength parameters can be obtained by using the multi-objective constraint optimization algorithm,which provides a new solution for the stability analysis and quantitative risk assessment of landslides in Heifangtai terrace.

关 键 词：黄土滑坡 稳定性反分析 多目标优化 遗传算法 滑面预测 灾害地质. 

分 类 号：P694[天文地球—地质学]