薄基岩浅埋煤层覆岩采动裂隙发育规律研究

Developing Law of Thin Bedrock Shallow Buried Coal Seam Overburden Strata Fracture

在分析东胜矿区某煤矿Ⅱ_(-3)煤层覆岩特征的基础上,采用有限元数值模拟和相似材料模拟2种方法模拟了薄基岩浅埋深煤层综放条件下的覆岩运移破坏过程。模拟结果表明,采动覆岩塑性破坏区的形态经历了"半圆拱形"-"马鞍形"-"拱箱形"的演化发育过程;随着采动空间的增大,采空区两端超前破坏裂隙扩展速度较中部变慢,最大导水裂隙带发育高度位于采空区中部,为76 m;采空区两侧应力集中程度呈现差异化现象,推进方向一侧应力集中程度较小,原始开切眼处应力集中程度较大。

Based on the analysis of Ⅱ-3 coal seam overburden strata characteristics of a coal mine which belongs to Dongsheng mining field, using the two simulation method： finite element and similar material simulation to simulate the migration and demolition process of overburden strata of thin bedrock shallow buried coal seam under full-mechanized caving mining. The simulation results show that the mining overburden plastic zones form experienced a evolution of ＂semicircular＂-＂saddle＂-＂arch box＂; with the increase of mining space, the advanced destroyed fissure′s extension speed on both ends of the minedout area is slower than the central, maximum height of water flowing fractured zone development is located in the middle of a moine-out area, that is 76 m; stress concentration showed differences phenomenon on both sides of mined-out area, the advancing direction side showed less stress concentration, at the open-off cut it showed large stress concentration.