大柳塔煤矿综采工作面压架冒顶机理研究

Study on mechanism of powered support jammed and roof falling in fully-mechanized coal mining face in Daliuta Mine

针对大柳塔煤矿52304综采工作面在回撤阶段发生的压架冒顶事故,采用现场实测、数值模拟和理论分析对事故的原因和防治对策进行研究。研究结果表明:因受特殊回撤工艺的影响,沿垂直于工作面方向布置的调节巷导致煤体应力集中系数过大,引发工作面与调节巷交叉处发生大面积片帮,最终因端面距超过临界值引发端面冒顶。同时破断块体因失去啮合力而大幅回转切落导致压架,并进一步恶化顶板状况,造成52304工作面在支架支撑力足够的情况下仍发生严重压架冒顶事故。由此确定了相应的防治对策,通过采用加强调节巷围岩的支护、优化回撤巷道的布置和选择非来压时期挂网等措施来预防事故的发生,并得到了52303工作面安全回撤的验证。

According to the powered support jammed and roof falling accidents occurred in the face equipment remove stage of No. 52304fully-mechanized coal mining face in Daliuta Mine,a site measurement,numerical simulation and theoretical analysis were applied to study on accident causes and the prevention and control countermeasures. The study results showed that due to the influences by the special remove technique,the adjustment gateway set along the perpendicular to the coal mining face direction would cause the coal stress concentration coefficient too high,and would cause large area spalling occurred at the cross section between the coal mining face and the adjustment gateway and finally due to the face front distance over the critical value would cause the roof falling at the face front area.Meanwhile due to the meshing force lost,the broken rock blocks would highly rotate and cause the powered support jammed. Thus the roof condition would be further worse and under the support resistance insufficient of the powered support in No. 52304 coal mining face,serious powered support jammed and roof falling accidents occurred still. Therefore the relevant prevention and control countermeasures were proposed,the enhanced surrounding rock support in the adjustment gateway,the optimized layout of the face equipment remove gateway,the mesh pavement selected at the strata not pressurized period and other measures were applied to the prevent and control of the accident occurrence. The equipment safety remove from No. 52303 coal mining face was verified.