煤矿覆岩空间结构OX-F-T演化规律研究

 煤矿工作面高强度、大尺度快速推进，导致采场覆岩运动范围增大，空间结构复杂。多工作面情况下，工作面与采空区覆岩结构协同运动，相互影响，造成的矿山动力灾害，称之为覆岩空间结构失稳型动力灾害。根据工作面上覆岩层边界状态的不同，将覆岩空间结构分为OX，F与T型3类。研究OX-F-T演化特征，即顶板O-X破断形成的OX结构为覆岩基本形式，同时又作为相邻工作面的边界条件，一侧为OX结构形成F型覆岩结构，两侧存在OX则形成T型覆岩结构。阐述不同结构的断裂运动规律，并将各结构进行详细分类。利用现场SOS微震监测系统，分别选取代表OX，F与T覆岩结构的单一工作面、双工作面、孤岛工作面，分析各工作面开采过程中的震源分布规律。针对不同覆岩结构特征，提出不同的防治措施，为冲击震动的预防工作提供理论指导。

STUDY OF OX-F-T SPATIAL STRUCTURE EVOLUTION OF OVERLYING STRATA IN COAL MINES

The rupture and movement scope of overlying strata increase sharply since the high strength and rapid exploitation of the longwall mining faces;and the spatial structure formed by fractured strata becomes much more complex.The overlying strata would move and interact coordinately when more workfaces exist;hence leading to mining dynamic disasters that defined as spatial structure instability in this paper.Based on the boundary conditions,three basic forms that named OX,F and T structure are identified,respectively.The OX-F-T evolution of the overlying strata is presented that the O-X fracture is the elemental structure of overlying strata and also the boundary of adjacent workface,one side is OX constitute F structure,and both side with OX is T structure.The characteristics and detailed classifications for each type are elaborated.The microseismic system is used for on-site monitoring,single,double and isolated workfaces that represent the OX,F and T structure are selected respectively to research the distribution rules of seismic events;the results confirmed the OX-F-T spatial structure feature.At last,specialized methods are proposed targeted to workfaces with different spatial structures.The research results provide theoretical guidance for dynamic disaster prevention and control in coal mines.