土质滑坡运动全过程物质点法模拟及其应用

发布时间：2018-04-22 03:32

本文选题：土质滑坡 + 运动全过程　；参考：《工程地质学报》2017年03期

【摘要】：物质点法(MPM)属于一种无网格数值计算方法,它可导入各种土体本构模型,考虑土体流固耦合行为,能够有效模拟土质滑坡大变形及超大变形。本文介绍了物质点法基本原理、控制方程与求解格式;基于5种物质点法的多孔介质表征模型,简要回顾了土质滑坡运动全过程物质点法模拟的最新研究进展。采用单套单相物质点模型,对深圳"12·20"人工堆填土滑坡全过程进行了物质点法模拟,使用了线性加载方式确定初始应力场,并使用了Drucker-Prager屈服准则弹塑性本构模型、GIMP算法与MUSL求解格式。模拟结果表明,该边坡发生失稳后,最大滑距达510m,滑坡范围纵向间距为1050m,最小滑坡角5.95°,均与观测结果相吻合。土体内部等效塑性应变区的演化趋势显示,滑坡机制为渐进式破坏,具体表现为:坡趾土体首先沿基岩界面发生剪切破坏,随后坡顶出现拉张裂隙,坡趾与坡顶塑性区分别沿基岩界面向坡体内部发育,形成贯通滑动面后滑动加速,超大变形出现。物质点法模拟滑坡运动全过程有助于理解滑坡致灾行为,可为滑坡防治提供参考。
[Abstract]:Material point method (MPM) is a meshless numerical method, which can introduce various constitutive models of soil and consider the fluid-solid coupling behavior of soil. It can effectively simulate the large and large deformation of soil landslide. In this paper, the basic principle, control equation and solution scheme of material point method are introduced. Based on five kinds of material point method, the latest research progress of material point method simulation in the whole process of soil landslide movement is briefly reviewed. A single set of single-phase material point model is used to simulate the whole process of "1220" artificial landfill landslide in Shenzhen, and the initial stress field is determined by linear loading method. The Drucker-Prager yield criterion is used to model the elastoplastic constitutive model and the GIMP algorithm and the MUSL solution scheme are used. The simulation results show that the maximum slip distance is 510m, the longitudinal distance is 1050m, and the minimum slope angle is 5.95 掳, which is consistent with the observed results. The evolution trend of equivalent plastic strain zone inside the soil mass shows that the landslide mechanism is progressive failure, which is shown as follows: the slope toe soil first occurs shear failure along the interface of the bedrock, and then the tensile fracture occurs at the top of the slope. The plastic zone of slope toe and slope top develop along the interface of bedrock to the slope body, and the slip accelerates after passing through the slip surface, and the super-large deformation occurs. The whole process of simulating landslide motion by material point method is helpful to understand the behavior of landslide disaster and provide reference for landslide prevention and control.
【作者单位】：南京大学地球科学与工程学院;
【基金】：国家自然科学基金重点项目(41230636) 江苏省自然科学基金项目(BK20160366) 苏州市科技计划项目(SYG201613)资助
【分类号】：P642.22

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