采场顶板结构预裂切割对围岩控制的影响

The Impact of Pre-split Cutting of Stope Roof to the Surrounding Rock Control

根据关键层预裂切割对巷道围岩大结构和采场顶板结构影响的分析,得出了预裂缝将采场顶板围岩的固定边界变为了铰接边界,缩短了顶板边界条件的转化过程。预裂缝破坏了采场围岩基本顶的连续性,降低了采场顺槽侧向煤体支承应力。短悬臂梁将上覆岩层部分载荷转移到了煤体深部,减小了顺槽围岩塑性屈服范围。因此,对顶板预裂切割能有效起到减弱顶板边界约束和控制围岩破断的作用。

By analyzing the impact of the pre-split cutting of key stratum to big structure of laneway surrounding rock and the structure of stope roof, the pre-split can change the fixation boundary of stope roof surrounding rock into the hinged joints boundary. This shortens the transform process of the boundary of the roof hoard. The pre-split breaks the roof board continuity, and lowers the supporting stress of stope laneway side. Short cantilever beam transfers the part of load from upper strata into the depth to reduce the plastic yield scope of surrounding rock in stope laneway. Therefore the pre-split cutting of stope roof can weaken the boundary restriction of stope roof and control the fracture function of surrounding rock.