中文摘要：

基于切顶短臂梁理论,分析无煤柱切顶自成巷技术原理,结合柠条塔矿施工经验,总结出＂支、切、护、封＂四步成巷工艺。通过建立联孔聚能爆破力学模型,分析无煤柱自成巷聚能爆破机制,得出联孔爆破损伤贯通判据条件,并结合试验巷道围岩特性,进行聚能切缝关键参数设计。综合运用理论分析、数值模拟及现场实测,对无煤柱自成巷切缝前后工作面和巷道矿压分布规律和演变机制进行系统研究。结果表明,由于切缝结构面切断巷道顶板与工作面顶板岩体间的应力传递路径,改变顶板岩层结构形态,工作面和巷道矿压分布发生明显变化。切缝对工作面矿压影响有一定范围,切缝影响区内周期来压强度有所减小,周期来压步距有所增大。切缝引起的充填结构的支撑作用是造成工作面顶板压力减小的直接原因,来压控制关键层上的有效荷载减小是导致来压步距增大的根本原因。受切缝影响,碎石帮顶板岩体将经历＂垮落→压实→稳定＂的演变过程,充分利用采空区碎胀矸石的自承载特性和巷道围岩的协同支撑作用,可有效减小支护强度,增强巷道稳定性。

英文摘要：

Based upon the cutting cantilever beam theory and the construction experience in Ningtiaota coal mine,the mechanism of gob-side entry by roof cutting was analyzed and the key processes of this novel no-pillar mining method was proposed. A double blast-hole mechanical model was established to obtain the cutting-through criterion of adjacent holes. The key parameters for the cumulative blasting was obtained considering the roof lithology of mining face S1201. The stress distribution and development before and after the roof cutting in both the mining face and the entry were studied systematically by means of theoretical analysis,numerical simulation and field measurement. The results indicate that the mine pressure at the working face and retained entry changes a lot before and after the roof cutting,mainly because the cutting process alters the roof connection and prevents the stress propagation from the gob roof to the entry roof. The periodic pressure strength reduces while the periodic roof weighting pace increases to a certain extent within the area of roof cutting influence. Analysis also shows that the supporting role of the gangue filling body is the immediate reason for the pressure strength reduction,and the decrease of the effective loading acting on the key stratum is the substantial cause for the roof weighting pace to increase. The gob rock masses experience the caving,compacting and stabilizing processes due to the roof cutting. Fully utilization of the bearing capacity of hulking gangues and the collaborative support of surrounding rocks are the effective ways to reduce the supporting intensity and increase the stability of surrounding rocks.