掘进巷道突水溃砂高压扰动注浆技术与应用

High-pressure jet disturbance grouting technology for water and sand inrush in roadway tunneling and its application

为了对弱胶结地层条件下的掘进巷道突水溃砂进行治理,以宁东煤田麦垛山煤矿2煤大巷掘进期间突水溃砂为研究对象,针对地面治理工程量大、周期长、井下常规治理风险高等问题,采用井下挡水墙建造、高压扰动注浆、钻注一体化和孔口控压保浆技术,完成了突水溃砂点封堵体的构筑。结果表明:通过在巷道内建造挡水墙,可以有效控制注浆期间的水砂淹没范围,经过对挡水墙及其围岩强度的核算,挡水墙能够至少抵抗1.64 MPa的压力,大于顶板含水层1.2 MPa的水压。首先在距离突水溃砂点较远的区域采用高压扰动注浆建造1号封堵体,将水砂淹没范围进一步缩小,然后在距离突水溃砂点较近的区域继续施工2号封堵体,对突水溃砂点周边进行治理;研发钻注一体化技术及钻具,能够避免钻孔在退钻后塌孔,影响后续注浆,实现钻探和注浆一体化作业。发明了孔口控压保浆装置,达到了在20 MPa注浆压力条件下浆液高效利用的目的;对巷道内松散砂体固结形成的封堵体采用取心和压水试验进行质量检验,取心完整,并且封堵体在1.8 MPa水压的作用下不漏水,说明封堵体质量良好。采用高压扰动注浆对掘进巷道内突水溃砂进行治理,具有安全、高效、经济等特点,并且可以有效避免治理期间二次灾害的发生。

In order to control the water and sand inrush in roadway tunneling under weak consolidated formation condi-tions,taking water and sand inrush during the No.2 coal seam roadway tunneling in Maiduoshan Coal Mine of Ning-dong Coalfield as the research object,the problems of large amount of engineering,long period of surface treatment and high risk of underground treatment were solved.The construction of the blocking body at the water and sand inrush point was completed by using the water-retaining wall construction technology,high-pressure jet disturbance grouting technology,the integration of drilling and grouting technology,and the pressure control and slurry retention technology.The results show that the flooded area of water and sand can be controlled effectively by constructing the water-retain-ing wall in the roadway during grouting.With the strength of the water-retaining wall and surrounding rock being calcu-lated,the water-retaining wall can resist at least 1.64 MPa of pressure,which is greater than the water pressure of the roof aquifer(1.2 MPa).Firstly,the No.1 blocking body was constructed by high-pressure jet disturbance grouting in the area far from the water and sand inrush point to reduce the submerged range.Then,the No.2 blocking body was constructed in the area close to the water and sand inrush point to control the surrounding area.The development of integ-rated drilling and grouting technology and its relevant equipment can avoid borehole collapse after drilling,which af-fects subsequent grouting,and achieve continuous drilling and grouting operation.The orifice pressure control and slurry retention device was invented for the efficient use of grouting under the pressure of 20 MPa.The quality of the blocking body formed by the consolidation of loose sand in the roadway was tested by the coring and water injecting test.The coring was complete and the blocking body was watertight under 1.8 MPa water pressure,indicating that the block body has a good quality.The use of high-pressure jet disturbance grouting to control water and sand inrush in the roadway is safe,efficient and economical,and can avoid the occurrence of secondary disasters during treatment effectively.