岩溶坡体裂隙对山体的稳定性起到了控制作用。为研究采动和裂隙水作用下含深大裂隙岩溶山体的失稳破坏机制，依托贵州纳雍普洒“8·28”特大崩滑案例，在现场调查的基础上，分析了山体崩滑特征，采用离散元UDEC数值模拟，研究了地下开采和裂隙水渗流耦合作用下含深大裂隙岩溶山体的变形破坏过程和失稳机制，分析了采动诱发含深大裂隙山体的破坏特征，讨论了裂隙水渗流对采动山体变形的作用规律。结果表明，采动对坡体变形的影响是一个随开采不断调整的过程，随开采进行，坡体变形由坡体整体下沉转变为坡体中部临空挤出。岩溶山体的深大裂隙对坡体的变形和破坏起控制作用，其中延伸最长的主裂隙决定了坡体的破裂演化形式。坡体破坏时，坡顶岩体沿主裂隙向下滑移，挤推中、下部坡体，在中、下坡体内形成潜在滑面，潜在滑面向主裂隙底部扩展并贯通。采动作用下含深大裂隙岩溶山体的整体失稳破坏过程为：坡体沉陷变形—坡顶向坡内倾倒—主裂隙闭合—坡体上部沿主裂隙滑移—主裂隙开裂—坡体中部挤出—中、下部岩体破碎—潜在滑面贯通—崩滑形成。地下开采前，裂隙水是引起坡体变形的主要因素，但对坡体稳定性影响不大。开采后，采动对坡体的变形起主导作用，水力对坡体变形和破坏的贡献取决于开采阶段。随着开采的进行，开采对坡体的扰动强度先增加后减小，水力促进坡体变形的作用也先增加后减小。开采扰动越强烈，水力作用越显著，反之水力作用越弱。

The stability of karst slope is controlled by karst fracture. To study the instability and failure mechanism of karst mountain with deep and large fissures under the action of mining and fissure water, taking the case of “8·28” landslide in Pusa, Nayong County, Guizhou Province, as an example, based on field investigation, the characteristics of the landslide are analyzed. By using UDEC, the deformation and failure process and instability mechanism of karst mountain with deep and large fissures under the coupling of underground mining and fissure water seepage are investigated, and the mining-induced failure in the mountain with deep and large fissures is analyzed, in addition, the effect of fissure water seepage on the deformation of mining mountain is discussed. The results show that the influence of mining on the slope deformation is a process of continuous adjustment with mining. With the development of mining, the deformation of the slope changes from overall subsidence to extrusion in the middle of the slope. The deformation and failure of the slope are controlled by deep and large fissures and the fracture evolution form of the slope is determined by the longest fissure. When the slope is destroyed, the rock mass at the top of the slope downslides along main fracture, pushing the middle and lower slopes, forming a potential slip surface in the middle and lower slopes, and the potential sliding surface extends to the bottom of main fracture and penetrates through. The whole failure process of karst mountain body with deep and large fractures under the mining action is as follows: slope subsidence deformation-slope top toppling into the slope-main fissure closing-upper slope sliding along main fissure-the main fracture cracking-extruding in the middle of slope-the middle and lower rock mass being broken-potential sliding surface connecting-collapse forming. Before underground mining, the fissure water is the main factor causing slope deformation, but it has little effect on slope stability. After mining, the mining plays a leading role in slope deformation, and the contribution of hydraulic to slope deformation and failure depends on the mining stage. With the development of mining, the disturbance intensity of mining on the slope increases first and then decreases, and the effect of hydraulic pressure on slope deformation increases first and then decreases too. The stronger the mining disturbance is, the more significant the hydraulic effect is, conversely, the weaker the hydraulic effect is.

1 滑坡基本概况

   1.1 基本地质条件

   1.2 气象水文条件

   1.3 岩溶及裂隙发育特征

   1.4 采矿活动

2 坡体变形失稳过程

   2.1 沉陷-拉裂变形阶段

   2.2 山体整体溃屈阶段

3 采动-裂隙水耦合下含深大裂隙岩溶山体破坏数值模拟实验

   3.1 UDEC数值模拟方案

   3.2 数值模拟结果分析

   3.3 采动和裂隙水作用下含深大裂隙岩溶山体失稳破坏机理分析

4 结论