浅埋煤层群开采的区段煤柱应力与地表裂缝耦合控制研究

为了探索浅埋煤层群开采减缓煤柱集中压力并实现地表均匀沉降和地表裂缝耦合控制,通过物理模拟和数值计算揭示了煤层群开采中不同区段煤柱错距的间隔岩层破断规律、煤柱集中应力分布规律、覆岩和地表裂缝发育规律及地表沉降规律,掌握了不同区段煤柱错距与煤柱应力集中及覆岩裂隙演化的关系。研究得出,根据煤层间岩层的破断规律,确定合理的上下煤层区段煤柱错距,可避免上下煤层区段煤柱间的集中应力叠加和煤柱支承影响区的岩层非均匀沉降,实现煤层群开采的应力和裂缝耦合控制。建立了浅埋煤层群开采的煤柱群集中应力和地裂缝控制模型,得出了避开煤柱集中应力和实现地表均匀沉降的耦合判据,揭示了减缓煤柱群集中应力和实现地表均匀沉降的机理。

Coupling control of pillar stress and surface cracks in shallow coal seam group mining

In order to investigate the coupling control of reducing coal pillar pressure concentration and realizing uniform surface subsidence to reduce surface cracks in shallow buried coal seams mining,the physical simulation and numerical calculation are employed.The interval strata breaking form,the concentrated stress distribution of coal pillars,the overburden and surface cracks and the ground surface subsidence in different coal pillar stagger distances are obtained.The relationship of the coal pillar stagger with the evolution of coal pillar stress concentration and of overburden fracture is discovered.According to the study,the determination of the reasonable upper and lower coal pillars stagger by interval layer breaking form can avoid the section coal pillar concentrated stress superposition and non-uniform strata subsidence in coal pillar supporting influence area,and realize the coupling control of stress and cracks in shallow coal seam group mining.In this paper,the control model of concentrated stress and ground crack of coal pillar group is established,and the coupling criterion to avoid the coal pillar concentrated stress and realize the uniform surface subsidence is put forward,so the mechanism of reducing the stress concentration of coal pillar and realizing the uniform subsidence of the ground surface is revealed.