水力造穴增透预抽在掘进面区域防突中的应用试验

Application Test of Permeability Enhancement by Hydraulic Jet Cavity in Regional Outburst Prevention of Heading Face

以山西潞安集团一缘煤业的150112回风巷掘进工作面为试验地点,对水力造穴增透顺层条带预抽区域防突措施进行研究。试验采用前进式造穴工艺,在掘进工作面迎头打设5个长度为120m的造穴钻孔,实际造穴52个,造穴规格为长1m×Φ0.8m的圆柱体,造穴水压为16~18MPa,总出渣量150t。通过本次试验得出:造穴钻孔的标况日平均抽采纯量由未造穴时的62m^3提高到316m^3;掘进过程中巷道回风流瓦斯浓度由原来的0.7%降低到0.4%;造穴区域的软分层相比未造穴区域煤层含水量升高,煤质变硬,粉煤减少,掘进过程中产尘量减少,瓦斯动力次数减少,掘进效率大幅提高。但由于水力造穴过程会对煤层结构及顶、底板产生一定的破坏,所以在巷道掘进期间需加强顶板及巷道两帮的支护管理,且水力造穴技术不适用于造穴影响范围内巷道顶、底板有遇水后变软岩层的矿井。

Permeability enhancement by hydraulic jet cavity gas pre-drainage to prevent regional outburst wewe tested,the test site was selected in the 150112 air return way heading face of Yiyuan Coal Mine of Shanxi Lu’an Group.The process of forward hydraulic jet cavity was adopted in the test.5 hydraulic jet cavity drilling with length of 120 m were hit on the heading face,and 52 cavity were jet.The size of the cavity was a cylinder of 1 m×0.8 m,the water pressure of the cavity making was16~18 MPa,and total amount of slag was 150 t.The results were as follows:the average gas extraction amount of boreholes with hydraulic jet cavity was increased from 62 m^3/d to 316 m^3/d.In the process of tunneling,the gas concentration of heading face return air was reduced from 0.7%to 0.4%.The water content in coal seam of jet cavity area was higher than that in the non-jet cavity area,pulverized coal was reduced,the dust amount in tunneling was reduced,the number of gas dynamics was reduced,and the efficiency of tunneling was greatly improved.However,the process of hydraulic jet cavity will cause certain damage to the coal seam structure,roof and floor,so during the tunneling,the support management of the roof and roadway two sides shall be strengthened.Moreover,the technology of hydraulic jet cavity is not suitable for mines with water-weakenable stratum wthin the influence range of hydraulic jet cavity in the roadway roof and floor.