破碎顶板淋水巷道多层次注浆加固技术研究

Research on Multi-level Grouting Reinforcement Technology for Fractured Roof Watering Tunnel

3300巷局部区域顶板破碎且有一定淋水情况,顶板淋水不仅会导致围岩支护用锚杆索及金属网锈蚀而且容易导致顶板内软岩夹层泥化,导致顶板支护体系失效。结合3300巷现场情况,提出采用多层次注浆加固技术提高破碎顶板整体稳定性并封堵导水裂隙。具体在顶板破碎淋水段布置排状钻孔、定点钻孔,以便实现顶板全覆盖注浆以及局部补强注浆,同时钻孔分2次钻进、2次注浆;1次钻进深度2 m,采用水泥浆液,注浆压力1 MPa;2次钻进深度为3.5 m,采用化学浆液、注浆压力2.5~3.0 MPa;通过多层次注浆可在巷道顶板形成初注帷幕、复注帷幕,提升围岩加固以及导水裂隙封堵效果。现场应用后,3300巷顶板淋水问题得以较好解决,顶板及支护用锚杆、锚索钻孔等未出现淋水情况,现场采用的多层次注浆加固技术取得显著效果。

In some areas of lane 3300,the roof is broken and there is a certain degree of water seepage.Water seepage on the roof not only causes corrosion of anchor rods and metal mesh used for surrounding rock support,but also easily leads to mudification of soft rock interlayers inside the roof,resulting in the failure of the roof support system.Based on the on-site situation of lane 3300,it is proposed to use multi-level grouting reinforcement technology to improve the overall stability of the fractured roof and seal the water conducting cracks.Specifically,arrange rows of boreholes and fixed-point boreholes in the water pouring section of the broken roof to achieve full coverage grouting and local reinforcement grouting of the roof.At the same time,the boreholes are drilled in two stages and injected twice.Drilling depth of 2 meters once,using cement slurry with a grouting pressure of 1 MPa.Drilling depth of 3.5 meters twice,using chemical slurry and grouting pressure of 2.5~3.0 MPa.Through multi-level grouting,initial and secondary grouting curtains can be formed on the roof of the roadway,improving the reinforcement of surrounding rock and the sealing effect of water conducting cracks.After on-site application,the problem of water seepage on the roof of lane 3300 was well solved,and there was no water seepage in the roof and support anchor rods,anchor drilling,etc.The multi-level grouting reinforcement technology adopted on site achieved significant results.