底板深孔爆破卸压机理及底臌控制技术研究

高河矿E2305工作面胶带巷由于底板岩层强度低,在高应力作用下导致巷道底臌严重。利用FLAC3D分析了底臌发生的主要机理,经过理论计算和数值模拟计算,提出了底板深钻孔松动爆破方案。通过相似模拟,研究工作面回采过程中矿压显现、回采巷道附近围岩的应力分布、位移、巷道的破坏方式及程度的规律。对回采巷道底板岩层进行深孔爆破卸压处理后与原支护不爆破卸压的巷道底臌现象和规律做出对比,结果显示底板深孔爆破卸压能够解决底臌问题。工程实践表明:巷道最大底鼓量为55mm,最大底鼓速率为26mm/d,变形速率及底鼓量在巷道正常使用允许范围之内,底板卸压爆破后巷道变形尤其是底臌得到了有效控制,可以为相似条件下巷道底臌治理提供借鉴。

Study on pressure relief mechanism and floor heave control technology of deep hole blasting in bottom plate

The belt roadway of E2305 working face in Gaohe mine is seriously heave at the bottom of the roadway under the action of high stress due to the low floor rock strength.The main mechanism of floor heave is analyzed by FLAC3D, and the loose blasting scheme of deep borehole of floor is put forward after theoretical calculation and numerical simulation.By means of similar simulation, the law of mine pressure appearance, stress distribution, displacement and failure mode and degree of roadway in surrounding rock near the stoping roadway are studied.The results show that the bottom heave problem can be solved by blasting the bottom heave after the deep hole blasting unloading treatment, compared with the bottom heave phenomenon and the law of the roadway bottom heave without blasting unloading under the original support.The engineering practices showed that,the maximum displacement and the maximum rate of floor heave were 55 mm and 26mm /d, the displacement and rate of floor heave were with controllable range. The roadway deformation, especially the floor heave, is effectively controlled after floor pressure relief blasting.It can provide a reference for the treatment of roadway bottom heave under similar conditions.