裂隙介质动水注浆硅溶胶浆液扩散规律研究

Study on the Diffusion Law of Silica Sol Grout in Fractured Media under Dynamic Water Injection

摘要: 为揭示动水条件下裂隙介质注浆的浆液扩散机制，采用可视化平板裂隙模型试验与数值模拟，对比研究了单孔与双孔注浆时硅溶胶浆液在单一平板裂隙中的扩散形态与渗流压力演化规律。结果表明：(1) 浆液扩散形态呈“圆形–扁平椭圆形–U形”三阶段演化，动水作用是形态畸变的主导因素；(2) 单孔注浆扩散初期快、中后期慢，形态散乱而充填效率低，双孔注浆因两孔浆体相互约束，扩散边界稳定，逆水与竖向充填能力显著增强，14 s时充填面积由单孔的45%提升至90%；(3) 两种工况的起压顺序均为x轴正向 > y轴双向 > x轴负向，双孔注浆使y轴双向测点的起压时刻提前约7~9 s；(4) 数值模拟可再现扩散形态，但受二维建模限制，其充填面积与封堵时间与试验存在一定偏差。研究结果可为动水地层多孔注浆设计提供依据。

Abstract: To reveal the slurry diffusion mechanism of grouting in fractured media under dynamic water conditions, a comparative study was conducted using visual flat plate fracture model tests and numerical simulations, examining the diffusion patterns and seepage pressure evolution of silica sol slurry in a single flat plate fracture during single-hole and dual-hole grouting. The test fracture zone dimensions were 400 mm × 300 mm with an aperture of 5 mm, under a dynamic water head of 1 m and grouting pressure of 0.02 MPa. The results indicate: (1) The slurry diffusion pattern evolves through three stages-“circular-flattened elliptical-U-shaped”, with dynamic water being the dominant factor causing morphological distortion; (2) Single-hole grouting exhibits rapid initial diffusion but slower progression in the middle and late stages, resulting in scattered patterns and low filling efficiency. In contrast, dual-hole grouting achieves stable diffusion boundaries due to mutual confinement of the two holes, significantly enhancing counterflow and vertical filling capacity, with the filling area increasing from 45% (single-hole) to 90% at 14 s; (3) The pressure initiation sequence for both conditions follows the order: positive x-axis > bidirectional y-axis > negative x-axis, with dual-hole grouting advancing the pressure initiation time at bidirectional y-axis measurement points by approximately 7~9 s; (4) Numerical simulation can reproduce diffusion patterns, but due to the limitations of two-dimensional modeling, there may be deviations in filling area and sealing time compared to experimental results. The findings can provide a basis for designing pore grouting in dynamic water-bearing strata.