渗透注浆过程中水泥颗粒对土体孔隙的堵塞会产生滤过效应,滤过效应在浆液扩散过程中起着非常重要的作用。基于此,研究滤过效应对卵砾石层中注浆浆液扩散的影响。在总结浆液可注入性标准的基础上,考虑浆液滤过过程中水、水泥和土体的质量平衡,引入线性滤过定律,给出一种球孔扩散条件下考虑滤过效应的水泥浆浆液扩散模型,并通过模型理论结果和现场实测数据的对比,说明该方法的合理性和考虑滤过效应的必要性。不同注浆时间和水灰比条件下滤过效应对渗透注浆的影响分析表明,滤过效应导致土体的渗透阻力逐渐增大,土体中注浆压力随时间逐渐增加。浆液水灰比越小,注浆压力越大,滤过效应也越显著。
Due to progressive blocking of cement grains within the soil matrix, filtration of grout plays a significant role during grout dispersion process. The influence of filtration on the grout dispersion in gravel is studied. The injectability criterion of the grout is first summarized. Then the linear filtration law is introduced into the mass balance relationships of water, cement and soil to develop a cement grout dispersion model in spherical coordinates with account for filtration. The comparison between model results and experimental data proves the validity of the given model and the necessity of considering the phenomenon of filtration. In addition, the influences of filtration on permeation grouting under different injection durations and water-cement ratios are also studied. The results reveal that the penetration resistance increases gradually due to grout filtration, leading to the increase in grouting pressure with time. For grout with smaller water-cement ratio, the grouting pressure is larger and the influence of filtration is more obvious.