速凝浆液裂隙动水注浆扩散规律模拟试验

Model test on quick setting slurry diffusion law of crack grouting with dynamic water

针对地下工程动水注浆中常用的两种速凝浆液,水泥-水玻璃浆液(C-S浆液)与高聚物改性水泥浆液(GT-1浆液),开展动水条件下的裂隙注浆模拟试验,研究速凝浆液的注浆扩散规律,包括浆液扩散形态、注浆压力场分布、浆液留存率及动水流量变化规律,对比分析了C-S浆液与GT-1浆液对动水注浆的适用性。研究结果表明:动水环境对速凝浆液裂隙注浆扩散过程影响显著,顺水扩散与逆水扩散存在明显差异,注浆扩散前期浆液扩散形态为"非对称椭圆",逆水方向的半椭圆长轴长度小于顺水方向的半椭圆长轴长度,注浆扩散后期浆液从出流边界流出,浆液扩散形态为"U"形;动水流速较低时,C-S浆液与GT-1浆液均可以保持较高的浆液留存率,但是随着动水流速增加,浆液留存率显著降低;注浆压力由注浆孔向周围非线性衰减,且注浆影响压力场的范围有限;GT-1浆液相比C-S浆液具有明显的优越性,主要体现在浆液扩散范围、动水抗分散能力、堵水效率、可注性等方面。

For two types of quick setting slurry which are frequently used in dynamic grouting projects, that is, C-S slurry and GT-1 slurry, model tests on crack dynamic grouting with quick setting slurry were carried out. Grouting diffusion laws of quick setting slurry, including slurry diffusion pattern, grouting pressure field distribution, retention rate of slurry and variation law of dynamic flow, were studied, and applicability of C-S slurry and GT-1 slurry in dynamic grouting projects was compared and analyzed. Results show that： dynamic flow may remarkably affect the slurry diffusion process, and the downilow diffusion may significantly differ from the upflow diffusion. In the early stage of grouting process, the slurry diffusion pattern is asymmetric ellipse and the length of long axis of half ellipse in upflow is smaller than that in downflow. In the later stage of grouting process, the slurry diffusion pattern appears to be ＂U＂. When the dynamic flow is slow, both C-S slurry and GT-1 slurry can maintain high retention rate of slurry. With the increase of flowing speed, however, the retention rate of slurry may be significantly reduced. Grouting pressure may decrease nonlinearly with the distance to the axis of grouting role, and the influence scope of grouting is limited. GT-1 slurry shall be superior to C-S slurry in dynamic grouting projects in those aspects such as grouting diffusion range, dispersion resistibility of dynamic flow, water blocking efficiency, and so on.