综放工作面推近断层过程中顶板稳定性力学分析

Mechanics analysis of roof stability on the fully mechanized caving face approaching faults

为研究综放工作面推进顶板过程中的顶板力学结构,以中煤平朔井工三矿34201综放工作面过断层为工程原型,采用理论分析方法,推导了工作面推近断层面时基本顶和直接顶的力学平衡方程和力矩平衡方程,研究了基本顶和直接顶发生压垮支护系统和转动失稳的判据,定性分析了影响基本顶和直接顶稳定的主要因素.依据基本顶和直接顶失稳判据进行分析可知:基本顶和直接顶更易沿断层面转动失稳,基本顶的悬臂长度应随工作面推近断层而减小,当工作面距离断层5m时,基本顶悬臂长度应小于1.43m,否则基本顶可沿断层面上一点转动.这为控制基本顶和直接顶转动失稳提供了的力学依据.

In order to study the mechanical structure of roof before and after fully mechanized caving face passing by fault,the 34201 fully mechanized caving face of the No.3 coal mine,China Coal Pingshuo Group CO.,LTD was used as engineering prototype,and the theoretical analysis method was used to derive the mechanical equilibrium equation and moment equilibrium equation of basic roof and immediate roof when the work face is near fault plane,and study the criterion of crushed supporting system and the rotational instability of the basic roof and immediate roof.The main factors affecting the basic roof and immediate roof stability are qualitatively analyzed.The analysis of the basic roof and immediate roof instability criterion shows that the basic roof and immediate roof is apt to rotational instability along the fault plane.The length of the basic roof cantilever should decrease as the working face approaches the fault.When the working face is 5 m away from the fault,the length of the basic cantilever should be less than 1.43 m,otherwise,the basic roof can be rotated a little along the fault plane.This provides a mechanical basis for controlling the instability of the basic roof and immediate roof rotation.