急倾斜厚煤层综采工作面采动围岩破坏演化规律与成灾机理研究

Adoping the comprehensive mechanizied coal mining on steep-pitching thick coal seam is the sole approch and the urgent task to ensure the safety and high efficiecy. This project is based on a finished mining all high industral experiment on coal seam of over 3.5 m thick, maximum angle to 70 degree with the comprehensive mechanizied coal mining. It will take the working spot of steep-pitching thick coal seam with comprehensive mechanizied mining as the research subject. Through the study of evolution laws of stress field and fracure activity of overlying rock mass in comprehensive mechanized coal mining field, the project plans to find the rules of strata movement and characteristics of rock failure, the evolution law of fracture field, the condition of strata formation, the characteristic of losing instability or steady of overlying rock mass. Besides, the project aims to have a research on the floor of slipping damage and regions of steep-pitching thick coal seam, to explore the formation and evlution of the three- dimentional irregular stress field of surrounding rock face, to set up the mechanical systems of the "roof-support-floor" and explore the principle of its stability and dynamic disaster tendency. This project adopts the integrate research methods of thearetical analysis, similar material simulation in lab, numerical calculation and field investigation combining with actural measurement. The target of this project is to improve the level of surrounding rock control in coprehensive mechanized mining of steep-pitching s thick coal seam, to promote controlling effect of the surrounding rock and to guide the safe producing in mining field.

急倾斜厚煤层实现综合机械化开采是解决安全高效唯一途径和迫切任务，本课题以已经实现最大倾角70 ，3.5m厚度以上煤层一次采全高的综采工业实验为背景，采用理论分析、实验室相似材料模拟实验、数值计算方法和现场调研与实测相结合的综合研究方法，以急倾斜厚煤层综采工作面为研究对象，通过对综采采场采动覆岩破断运动及应力场演化规律的研究，掌握急倾斜厚煤层采场覆岩的破断运动规律、裂隙场的演化规律、覆岩结构的形成条件、结构失稳特征与稳定性等；研究急倾斜厚煤层综采工作面底板破坏滑移、破坏与分区；探索急倾斜厚煤层采场围岩三维非规则应力场形成与演化机制，建立急倾斜厚煤层开采"顶板-支架-底板"力学系统，探索三者之间稳定性规律及动力灾变机理，提高急倾斜厚煤层的综合机械化开采水平，提高采场围岩控制效果，指导工作面安全生产水平。

急倾斜厚煤层实现综合机械化开采是解决安全高效唯一途径和迫切任务，本课题采用理论分析、实验室相似材料模拟实验、数值计算方法和现场调研与实测相结合的综合研究方法，以急倾斜厚煤层综采工作面为研究对象，通过对急倾斜厚煤层综采开采稳定性规律及动力灾变机理研究，提高急倾斜厚煤层的综合机械化开采水平和围岩控制效果，保障工作面安全高效开采。课题研究的主要结论是：（1）急倾斜煤层走向长壁综采工作面矿压显现具有不均衡性和时序性，工作面中上部要比工作面下部承受更大的动载；一般情况下，工作面中部或中上部首先来压，工作面下部后来压。（2）沿倾斜方向不同区域对老顶的充填特征不同，工作面下部填实，中部填满，上部悬空。沿工作面倾斜方向冒落带和裂隙带呈现出非对称特征，且顶板垮落具有“时序性”。（3）急倾斜煤层走向长壁综采工作面开采时，“X”破断的长边与工作面线平行的，首先在工作面中部靠上方开裂，在板的上部形成弧三角形板要先于在板的下部形成弧三角形板。（4）以工作面中轴线为界支承压力分布呈现出典型的非对称特征。工作面中部或中部靠上区域底板中支承压力降低幅度较大，向工作面两侧底板中支承压力降低幅度较小。（5）煤层倾角越大，顶板破断对工作面支架工作阻力的影响越明显，尤其是顶板破断后期对工作面中上部的影响尤为明显。（6）降架使上邻架支撑力增加的幅度大于下邻架支撑力增加的幅度；升架会使上邻架的支撑力降低的幅度大于下邻架的支撑力降低的幅度。（7）建立了急倾斜煤层开采顶底板破断力学模型，提出了急倾斜走向长壁开采顶板的破坏条件和底板破坏判据。（8）倾角越大，底板破坏越严重，工作面支架和设备下滑、倾倒的可能性增加；支架与底板的摩擦系数与支架的下滑稳定性成正变，但是对底板的破坏性是先减小后增大。