露天转地下开采诱发边坡变形破坏FDM自适应预测

发布时间：2018-03-26 03:21

本文选题：数值模拟　切入点：有限差分方法(FDM)　出处：《中国地质大学(北京)》2016年硕士论文

【摘要】：随着陡倾露天铁矿开挖深度的逐步增加,在地表将形成高陡边坡。考虑到工程的稳定性、经济性、环保性,需要由露天开采转入地下开采。露天转地下开采的常规做法是无底柱分段崩落法,即从矿坑底部开始,自上而下分层开挖矿体。随着开采层数的提高,矿坑边坡的临空面逐步扩大,边坡岩体将会发生非连续、大变形、大位移的运动与破坏。因此为了确保工程的顺利实施,必须对边坡的变形破坏规律进行研究。本文首先阐明了有限差分方法(FDM)在预测露天转地下开采诱发边坡失稳时的不足之处,其次提出一种基于有限差分方法的自适应网格重划分的边坡失稳预测方法,最后将该方法付诸于工程实践。本文的主要工作及成果如下:(1)露天转地下开采诱发边坡变形破坏特征研究。根据露天转地下开采的特征,对边坡破坏形式进行探讨,进而指出使用有限差分方法在进行露天转地下开采预测边坡稳定性的不足之处。(2)基于网格自适应重划分的边坡变形破坏预测方法。在采用FLAC~(3D)软件计算过程中,如果节点位移过大,模型会出现畸形单元,此时数值计算不收敛,而且最大剪切应变增量带发生贯通,表征边坡破坏。通过开发相关算法及代码,搜索并获取畸形单元,进行网格重划分,使单元的形状能够满足数值计算的要求;为了保证计算的连续性,本文借助形函数,将网格重划分前的物理场量传递至重划分后的网格单元和节点上。(3)基于网格自适应重划分的边坡失稳预测方法的应用实例研究。根据鞍山眼前山铁矿的代表性地质剖面,利用ANSYS软件构建三维地质模型,并将其导入FLAC~(3D)软件中,进行数值模拟。当数值计算不收敛时,采用网格自适应重划分边坡变形破坏预测方法,实现滑坡模拟,再现了边坡由稳定到失稳再到稳定的动态发展过程。因此,该方法对有连续发生多次滑坡可能性的边坡工程稳定性分析具有借鉴意义。
[Abstract]:With the steep slope of open pit mine excavation depth increased gradually at the surface will form a high and steep slope. Considering the stability of engineering, economy, environmental protection, by open-pit mining to underground mining. The conventional practice of open pit and underground mining is sublevel caving method, namely from the mine pit bottom, top-down excavation with the increase of layers. Ore mining, surface mine slope gradually expanded, non continuous rock slope will occur large deformation, movement and failure of large displacement. So in order to ensure the smooth implementation of the project, it is necessary to study the rules of deformation and failure of slope. This paper illustrates the finite difference method (FDM) deficiency in the prediction of open-pit to underground mining induced slope instability, then proposed a slope based on the finite difference method of the adaptive remeshing instability prediction method, the method is put into In the engineering practice. The main work and results are as follows: (1) study on the failure characteristics of slope deformation induced by underground mining to open pit. According to the characteristics of open-pit to underground mining, discusses the failure form of slope, and then pointed out that the use of finite difference method in the prediction of deficiency of slope stability of open pit to underground mining (2). Deformation prediction method of slope based on grid adaptive remeshing. In the use of FLAC~ (3D) software in the process of calculation, if the node displacement is too large, the model will appear abnormal unit calculation does not converge at this point value, and the maximum shear strain increment took place through the characterization of slope failure. Through the development of related algorithms and code, search and access abnormal unit, remeshing of the element shape, can satisfy the requirements of numerical calculation; in order to ensure the continuity of the calculation, the shape function, the remeshing The grid node transfer unit and physical volume before to after partition. (3) application of prediction method of slope stability based on adaptive mesh remeshing. According to the Anshan Yanqianshan Iron Mine of the representative geological sections, 3D geological model was constructed by using ANSYS software, and the introduction of FLAC~ (3D) software in the numerical simulation. When the non convergence of the numerical calculation, the adaptive mesh remeshing of slope deformation prediction method, landslide simulation reproduces the slope from stability to instability and dynamic development process stable. Therefore, the method of continuous slope stability analysis of the landslide possibility repeatedly has reference significance.

【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD861.1

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