基于DDD离心加载法的黑山铁矿西帮边坡稳定性研究

RESEARCH ON THE STABILITY OF THE WEST SLOPE OF THE HEISHAN IRON MINE BASED ON THE DDD CENTRIFUGAL LOADING METHOD

  • 摘要: 非连续变形与位移分析方法(DDD)是一种新的岩石破坏全过程分析方法,该方法有效的结合了RFPA有限元方法及非连续变形分析(DDA)方法的优势,解决了有限元不能很好地进行大位移动态分析及DDA不能模拟岩石中新破裂的萌生、扩展过程的问题,真实再现了边坡由细观裂纹的演化直至宏观破坏的全过程。在原有的DDD方法的基础上,结合了传统的离心加载试验机理,形成了全新的DDD离心加载法。该方法不仅保存了DDD方法原有的计算特点,且实现了不用预先假定滑移面而是通过计算得出其滑移失稳面,更加符合工程实际。基于改进的DDD离心加载法,结合黑山铁矿西帮边坡给出的剖面及要进行崩落开采的实际工况,建立了二维的含有采空区的边坡稳定性分析模型。模拟了在有无锚索作用下的含有采空区边坡的滑移机理并进行了对比分析,分别分析了有无锚索作用下的含有采空区边坡由细观裂纹的演化直至宏观破坏的剪应力变化过程、安全系数、竖向及水平位移矢量的变化。结果表明:采空区外凸棱角区是边坡应力集中的关键点,边坡的失稳破坏过程有明显的张拉作用,与实际提供的工况现场取得了较好的一致性。锚索虽将断层以上坡体应力集中形态有效分散提高了边坡的安全系数、使得各向位移矢量的变化明显减小,但黑山西帮边坡仍然存在潜在滑移的可能,仍需后续的继续观测。

     

    Abstract: Discontinuous deformation and displacement analysis (DDD) is a new way for analyzing the slope failure process, and this method combines the advantage of finite element method of RFPA and discontinuous deformation analysis (DDA) effectively. The problems such as large displacements which cannot be analyzed by RFPA, by the fractured rock initiation, and by propagation process issues which cannot be simulated by DDA, can be solved by DDD. And it also revealed the whole production process of the microscopic crack of the slope until it is destructed. Based on the original method of DDD and conventional centrifugal load test mechanism, it has been converted into a new formation called DDD centrifugal loading. This method not only preserves the feature of the original DDD, but also attains the instability sliding surface of the slope. Based on the DDD centrifugal loading method, the sectional slope of west slope of the Heishan Iron Mine and determination of caving in actual working conditions that establish a two-dimensional model of the slope with hole. It simulated mechanism of the sliding slope with hole under the presence or absence of the anchor and it also analyzed the evolution of the shear process from microscopic cracks to macroscopic damage, the safety factor and the vertical and horizontal displacement vector. The results show that:the caving hole of the convex corners area of the slope is a key point of stress concentration, and there is a significant effect of tension on slope instability and failure process which got a good agreement with the actual provision of the slope. Although the anchor disperses stress concentration effectively, improves the safety factor of the slope, and reduce the displacement, it still has the possibility of destruction and need to observe continuously.

     

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