深部巷道注浆加固浆液扩散机理与应用研究

Research on the grouting diffusion mechanism and its application of grouting reinforcement in deep roadway

针对深部软岩巷道采用普通注浆工艺的不足,采用三步注浆工艺进行围岩加固,能取得更好的效果。对三步注浆浆液扩散机理进行探讨,并将三步注浆工艺应用于现场注浆工程。"一步"低压注浆充填壁后散体状碎石充填层,堵塞浅部围岩泄压通道;"二步"注浆主要针对围岩中的裂隙网络进行注浆,通过浆液固化充填、胶结作用提高围岩的自承载能力;"三步"注浆为预留注浆,对成型巷道变形较大处进行补强加固。虽然三步注浆工艺增加了注浆工序,但浆液扩散范围得到保证。注浆后检查影像表明:采用此注浆工艺的围岩注浆扩散深度普遍大于3 m,达到了预期注浆加固的有效范围。而注浆前后巷道的变形监测数据表明:三步注浆工艺大大改善了注浆加固围岩的效果,有效提高了岩体的自承载能力,围岩的整体稳定性得到有效控制。

For the deficiencies of common grouting technology in deep soft rock roadways, three-step grouting technology is proposed to reinforce the surrounding rock to get better results. The three-step grouting diffusion mechanism is explored in this paper, and the technique is applied to field engineering. Step one is to grout with low grouting pressure to fill the gravel pack interval and blocked the channels which relieves the grouting pressure in the shallow surrounding rock. Step two is mainly for the filling of the fractures space in the surrounding fractured rock to improve the bearing capacity of the sur-rounding rock through the effect of grout cementation and filling with grout solidifying. In step three grouting is prepared to further reinforce the strong deformation sections of the roadway. Although in-creasing the working procedures of grouting, the three-step grouting technology ensures the radius of grouting diffusion. The inspection holes monitoring shows that grouting diffusion depth is generally more than 3 m, and that the three-step grouting technology has achieved the expected effective range of grouting reinforcement. The roadway deformation monitoring datum of grouting before and after indi-cates that three-step grouting technology has greatly improved the effect of grouting reinforcement of surrounding rock and effectively improved the bearing capacity of rock mass,and thus the overall stability of surrounding rock of roadway is effectively controlled.