急倾斜厚煤层走向长壁开采底板破坏滑移机理

Damage and Slip Mechanism of Floor in Longwall Mining on the Strike of Steep and Thick Coal Seam

为掌握急倾斜走向长壁放顶煤工作面底板破坏和滑移机理,结合弹塑性力学相关理论分析了急倾斜煤层底板破坏的力学临界条件,采用数值模拟对宝积山矿急倾斜综放开采底板在无支护条件和木锚杆临时支护条件下进行了模拟,得到了相应的塑性破坏区,为急倾斜工作面底板管理提供理论基础。研究结果表明:工作面推进过程中的底板瞬时卸压是底板破坏的主要原因,由于煤层倾角较大,破坏的底板发生沿倾向滑移,破坏"顶板-支架-底板"系统的整体稳定性。应用木锚杆对底板进行临时支护,可有效控制底板破坏和滑移。

In order to obtain the damage and slip mechanism of steep longwall top coal caving face floor, this paper combined elastic-plas- tic mechanics theory to analysis the mechanical critical condition of steep coal seam floor damage.The numerical simulation was applied to simulate no supporting condition and temporary supporting with wooden bolt condition in fully-mechanized top coal caving face of steep and thick coal seam and obtained the corresponding plastic damage zone,provided a theoretical basis for the floor management of steep coal seam working face.The results showed that the maijor reason of floor damage was the instantaneous pressure relief of floor in the process of working face advancing.Due to the big coal seam angle, the damaged floor slipped along the dip direction which destroyed the overall stabil- ity of roof-support-floor system.Wooden bolt on the floor for temporary supporting could effectively control the damage and slip of floor.