“S”型覆岩空间结构煤柱导致冲击失稳的力学机制探讨

进入深部开采后，决定矿山压力显现程度的运动岩层在厚度和层面方向上已经超出传统的平面模型范围，所形成的覆岩空间结构的运动影响着采动应力场的分布，煤柱及其周围由于采动引起的应力重分布和应力集中是诱发煤柱冲击失稳的应力条件和根本原因。因此，通过分析覆岩空间结构的运动规律及其采动应力场分布，并以此探讨作用在残留煤柱的力源，是研究煤柱诱发冲击失稳机制的理论基础。以华丰煤矿六层煤残留煤柱为研究对象，通过研究四层煤开采形成的“S”型覆岩空间结构岩层运动特点和六层煤上覆岩层运动规律，分析作用在煤柱上的复合应力，探讨煤柱力源，通过应力计算和微地震监测分析煤柱及其周围的应力场的分布规律，研究煤柱导致动力失稳的应力条件和机制，研究结果表明，四层煤和六层煤开采形成的高应力是煤柱诱发动力失稳的应力条件，而煤柱及其周围形成的高应力差是动力失稳的根本诱因；基于煤柱应力分析，探讨高应力区煤柱卸压解危的措施。

MECHANISM DISCUSSION ON ROCK BURSTING CAUSED BY COAL PILLAR OF S-SHAPED OVERLYING MULTI-STRATA SPATIAL STRUCTURE

With the deepening of mining，dynamic disasters，the range of disaster-related rock formation motion is beyond the traditional plane model. The movement of overlying strata spacial structure affects the distribution of mining stress field；and the stress distribution and stress concentration of the coal pillar caused by mining are the stress condition and primary cause for rockburst. Therefore，an analysis of the movement rules and mining stress field distribution of overlying strata and a study of the pressure source which acts on the coal pillar by the movement of the S-shaped overlying multi-strata spatial structure are the theoretical basis on the study of mechanical mechanism of rockburst caused by the coal pillar. The residual coal pillar of the 6th layer in Huafeng Coal Mine is taken as research object. The movement rules of overlying strata of the 6th layer and the S-shaped overlying multi-strata spatial structure of four the 4th layer are studied，and the pressure source during the movement of S-shaped overlying multi-strata spatial structure of coal pillar is analyzed. The stress field of coal pillar is also analyzed and the mechanical mechanism and stress condition of rockburst are studied through the stress computing and the microseismic monitoring. The study results indicate that the high stress caused by the coal mining of the 6th layer and the 4th layer is the key stress condition for the rock burst of coal pillars， and the fundamental inducing factor of the rock burst of the coal pillar is the difference of high stress which exist around the coal pillar. Based on the stress computing，pressure relief methods of coal pillar are discussed.