基于弹塑性土体本构模型的滑坡运动过程SPH模拟  

SPH simulations of post-failure flow of landslides using elastic-plastic soil constitutive model

作　　者：胡嫚[1,2] 谢谟文[2] 王立伟[3] 

机构地区：[1]西南大学工程技术学院,重庆400715 [2]北京科技大学土木与环境工程学院,北京100083 [3]燕山大学建筑工程和力学学院,河北秦皇岛066004

出　　处：《岩土工程学报》2016年第1期58-67,共10页Chinese Journal of Geotechnical Engineering

摘　　要：滑坡的仿真模拟是分析滑坡运动过程并预测滑坡影响范围的重要手段之一。采用了基于岩土体弹塑性本构模型的光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)方法,模拟滑坡失稳后岩土材料的特性。该模型以经典弹塑性理论为基础,包含了线弹性变形和德鲁克-普拉格(Drucker-Prager,DP)屈服准则下非关联流动法则的塑性变形,由于考虑了岩土材料的塑性特征,该方法能够更加精确和真实地模拟滑坡运动过程。同时,结合地理信息系统(geographic information system,GIS)的数据管理与建模,进一步将该SPH模型应用到滑坡模拟的实例中。基于GIS平台,完成了能够自动生成计算模拟所需的滑坡粒子数据的C#程序。该程序同时生成了高精度的滑坡体实粒子和复杂、不规则的边界虚粒子。实现了一系列模型建模与模拟计算,并验证了该方法的精度,还将此模型与方法应用在汶川地震中引发的大光包滑坡实例中,模拟结果与现场收集数据十分符合。Modeling of post-failure flow of landslides is one of the important approaches that can be used to simulate landslide flow development and predict the landslide hazard zone. A Smoothed particle hydrodynamics（SPH） model based on the constitution of elastic–plastic constitutive mechanics for soil is developed for simulating the behavior of a class of geo-materials. The SPH soil model considers the plastic behavior of the materials, and hence it is very important for more accurate and realistic simulations of geo-materials of soil type. The implemented material laws in the SPH soil code include classical elastic-plasticity with a linear elastic part, and different applicable yield surfaces with non-associated flow rules. In order to apply the SPH method to actual landslide modeling, the geographic information system（GIS） is utilized to generate site-specific models. Thus a C# code is developed to generate the particles of a given landslide site, which produces realistic particle mass and actual complicated boundaries for the SPH soil model. With GIS enabled, complex topography and irregular boundary can be accurately and easily generated. To improve the accuracy of such a complicated landslide simulation, a modified approach is proposed to implement the complex topography representation of landslide mass and the effective treatments of the irregular and complicated boundaries generated from the GIS. The SPH soil code is applied to the well-known Daguangbao landslide triggered by Wenchuan Earthquake in 2008. The topographies after failure are compared with those obtained from field collected data, and good agreement is found.

关 键 词：滑坡 模拟 光滑粒子流体动力学(SPH) GIS 弹塑性土体 

分 类 号：TU411[建筑科学—岩土工程]