内摩擦角空间变异性对大型滑坡滑动距离的影响  

Influence of spatial variability of the internal friction angle on the run-out distance of large-scale landslides

作　　者：张卫杰 陈洪鑫 陈宇 姬建 ZHANG Wei-jie;CHEN Hong-xin;CHEN Yu;JI Jian(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210024,China;College of Civil and Transportation Engineering,Hohai University,Nanjing,Jiangsu 210024,China;Jiangsu Design of Century Architecture Co.,Ltd.,The New North District,Changzhou,Jiangsu 213022,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210024 [2]河海大学土木与交通学院,江苏南京210024 [3]江苏筑森建筑设计有限公司,江苏常州213022

出　　处：《岩土力学》2024年第11期3388-3398,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.52278344,No.51890912);江苏省优秀青年基金项目(No.BK20211575)。

摘　　要：自然条件下形成的地层中,岩土体的强度参数分布往往具有空间变异性。利用有限的强度数据预测大型潜在滑坡的滑动距离,难以全面反映大型滑坡滑动距离的变化范围,因此有必要结合强度参数的统计特征和分布规律开展滑坡滑动距离的随机分析,为滑坡灾害的防治工作提供参考。对此,基于宾汉姆模型、等效黏度和摩尔-库仑破坏准则,构建了滑坡大变形滑移过程的光滑粒子流体动力学(smooth particle hydrodynamics,简称SPH)方法。利用中心点法生成内摩擦角的随机场样本,通过蒙特卡洛模拟对滑动距离进行随机分析,从而获得了大型滑坡滑动距离的分布特征。选取羊宝地滑坡作为研究案例,通过模拟验证了SPH方法的可行性。通过建立和分析具有不同随机场参数的地层模型,验证了内摩擦角随机场离散的准确性,并校准了模拟参数。在此基础上,通过改变内摩擦角随机场变异系数、竖向波动范围和水平波动范围,分析了不同条件下滑坡滑动距离的极差和分布规律。结果显示:变异系数增大导致滑坡距离的极差增大,滑动距离表现出更强的离散性;竖向波动范围的增大会增大强度参数分布团块的尺寸,从而增大滑坡距离的极差;水平波动范围、竖向波动范围及变异系数均与滑动距离标准差呈正相关性,且水平波动范围的影响最小。The strength parameters of geotechnical bodies in strata formed under natural conditions often exhibit spatial variability.Predicting the run-out distance of potential large-scale landslides using limited strength data is challenging as it may not comprehensively reflect the range of changes in sliding distance.Therefore,it is necessary to conduct stochastic analyses of landslide sliding distance by combining statistical characteristics and distribution laws of strength parameters,providing a reference for the prevention and control of landslide disasters.This study presents a smooth particle hydrodynamics(SPH)method for modeling the large-deformation sliding process of landslides,based on the Bingham model,equivalent viscosity,and Mohr-Coulomb failure criterion.The mid-point method is used to generate random field samples of the internal friction angle.Monte Carlo simulations were conducted for stochastic analysis of the sliding distance,thereby obtaining the distribution characteristics of the run-out distance for large-scale landslides.The Yangbaodi landslide was chosen as a study case to verify the feasibility of the SPH method.The accuracy of the discretization of the internal friction angle random field was verified by establishing and analyzing geological models with different random field parameters,and the simulation parameters were calibrated.On this basis,the range and distribution pattern of landslide sliding distance under different conditions were analyzed by varying the coefficient of variation of the internal friction angle,as well as the vertical and horizontal scales of fluctuation.The results show that an increase in the coefficient of variation leads to an increase in the range of the landslide distance,with the sliding distance showing stronger discreteness;an increase in the vertical fluctuation range increases the size of the intensity parameter distribution clusters,which in turn increases the range of the landslide distance;both the horizontal and vertical fluctuation ranges,as well as th

关 键 词：大型滑坡 滑动距离 内摩擦角 变异系数 波动范围 随机分析 

分 类 号：TU457[建筑科学—岩土工程]