8.5 m大采高工作面矿压显现规律数值模拟研究

Research on numerical simulation of mine pressure behavior laws of 8.5 m mining height work face

研究浅埋巨厚煤层大采高综采工作面矿压规律和支架阻力,是实现安全高效开采的前提。根据煤岩的力学性质,运用数值模拟软件FLAC3D,从工作面顶板位移和应力变化特征、采场覆岩的空间变形破坏和运移特征和工作面支架阻力变化3个方面,研究了特厚煤层与厚煤层的矿压规律和支架阻力变化异同点。结果表明,工作面顶板位移随推进度呈近似线性变化,推进到130～140 m达到极限值,随后趋于稳定。应力变化出现明显的分区现象;采场覆岩空间整体呈现"O"型下沉破坏,地面出现锅底型式台阶;工作面支架阻力呈现大小交替的周期规律型变化,最大阻力相近。经过对工作面矿压规律和支架阻力的数值模拟分析,确定了厚煤层与特厚煤层在矿压及支架阻力变化方面具有相似的规律变化,而在来压步距和最大阻力值等整体数值方面特厚煤层比厚煤层呈现更大增长趋势。

It is the precondition to realize safe and efficient mining to study the mining pressure laws and support resistance of fully mechanized mining face with large mining height in the shallow-buried thick coal seam. According to the mechanical properties of coal and rock,by using numerical simulation software FLAC3D,from three aspects of the characteristics of work face roof displacement and stress changing,the overburden rock deformation damage and migration characteristics and work face support resistance change,the extra-thick coal seam and thick coal seam mine pressure laws and the similarities and differences in support resistance changes were studied. The results showed that the roof displacement was approximately linear change along with the advance degree,reaching limit when advancing 130~140 m,then tended to be stable. The pressure appeared obvious zonal phenomenon. The overburden space of the stope presented "O" type subsidence failure,and the bottom of the pot type steps appear on the ground. The support resistance of the work face changed regularly and the maximum resistance was close to each other. Through the numerical simulation and analysis of the mine pressure laws and the support resistance of work face,it was determined that thick coal seam and extra-thick coal seams had similar laws in the changes of mine pressure and support resistance,while the overall value of the pressure step distance and the maximum resistance value of extra-thick coal seam presented a greater growth trend than that of thick coal seam.