论文部分内容阅读
控制顶板下沉是综放沿空留巷成功的关键,为研究综放沿空留巷顶板下沉规律,根据能量守恒和损伤力学的理论,建立了综放沿空留巷顶板下沉损伤力学模型,推导出顶板下沉量的计算公式,并分析了顶板下沉量与其15个影响因素的定量关系。结果表明:直接顶、顶煤、巷旁支护体的有效弹性模量三者耦合,大部分顶板下沉量由有效弹性模量较小者吸收;顶板下沉量随支护体宽度增加而降低,支护体宽度达4 m左右时,下沉量基本保持不变;顶板下沉量随巷道宽度、采高、顶煤厚度和直接顶厚度增加而增加;顶板下沉量随关键块给定载荷的增大而急剧增加。关键块参数对顶板下沉具有决定作用,提高巷旁支护强度,可减小关键块破断长度和回转角,使关键块破断位置靠近巷旁煤壁,有效减小顶板下沉;巷内支护阻力、直接顶容重和顶煤容重对顶板下沉量影响较小。
Controlling the roof sinking is the key to the success of fully mechanized top-coal caving face. In order to study the roof subsidence law of gob - side entry retaining in fully mechanized caving face, according to the theory of energy conservation and damage mechanics, Model, the calculation formula of roof subsidence is derived, and the quantitative relationship between roof subsidence and its 15 influencing factors is analyzed. The results show that the effective elastic moduli of direct roof, top coal and roadside support are coupled, and most of the roof subsidence is absorbed by the smaller effective elastic modulus. The roof subsidence decreases with the width of supporting body increasing , When the width of support body reaches about 4 m, the amount of subsidence remains basically unchanged; the amount of roof subsidence increases with the width of roadway, mining height, the thickness of top coal and the thickness of direct roof; The load increases sharply. The key block parameters have the decisive effect on the roof subsidence and improve the roadside support strength can reduce the key block breaking length and rotation angle, so that the key block rupture location near the roadway coal wall, effectively reducing the roof sinking; laneway support Resistance, direct top weight and top coal weight have little effect on roof subsidence.