巨厚煤层大断面临空煤巷综放矿压规律模拟研究

Numerical simulation about the mine pressure law with sub-level caving mining of large section roadways along gob in extremely thick coal seam

为了掌握巨厚煤层大断面临空煤巷综放开采过程中的矿压分布规律，以塔山矿5203巷为研究对象，利用数值模拟的手段再现了煤炭开采的全过程，并对围岩位移、锚杆锚索轴力以及围岩应力等矿压显现进行了监测，研究表明：采动对矿压显现的影响可以分为无影响、微影响和强影响三个阶段，距工作面的距离分别为大于120m、120～50m和小于50m；随着工作面的临近，锚杆、锚索轴力逐渐增加，但当距工作面距离小于14m后，上述轴力迅速降低，且采动对煤柱侧锚杆的影响较实体煤侧大，而对锚索的影响较为均匀；巷道开挖后，有效的支护限制了围岩的破坏，使巷道周围集中应力达到17MPa；煤层回采后，煤体被超前支承压力破坏而使其应力得到释放，在煤柱或煤体内出现多个应力峰值。

Purpose to control the mine pressure law with sub-level caving mining of large section roadways along gob in extremely thick coal seam, reproduces the whole process of coal mining by numerical simulation based on 5203 roadway in Tashan Coal Mine,and monitored the law of rock displacement, axial force and rock anchor bolt stress, etc. The results showed that ： the influence on strata of mining has no effect stages, micro-impact stages and high-impact stages, the distances from the face were more than 120m, 120~ 50m and less than 50m; the axial force of anchor gradually increased with the face of approaching, but the axial force decreased rapidly when the distance is less than 14m away from the face,and the effect of mining on cables near coal pillar is larger than others; effective supporting limit the destruction of roadway excavation rock,and the stress concentration around the tunnel reaches 17MPa;coal is damaged under the enormous lead abutment pressure and its internal stress is released after coal mining, so coal or coal pillar have multiple stress peaks.