考虑浆液黏度时空变化的速凝浆液渗透注浆扩散机制研究

Penetration grouting mechanism of quick setting slurry considering spatiotemporal variation of viscosity

速凝类浆液的黏度时变性及双液注浆方式导致浆液黏度空间分布不均匀,在渗透注浆理论模型中应当考虑浆液黏度空间分布不均匀性的影响。基于黏度时变性宾汉流体本构模型,引入了描述渗流过程的均匀毛管组模型,建立了恒定注浆速率条件下考虑浆液黏度时空变化的一维渗透注浆扩散模型。设计了一维可视化渗透注浆扩散模拟试验系统,获得了不同介质渗透率及不同注浆速率条件下水泥-水玻璃浆液(C-S)注浆压力随时间变化规律。研究结果表明:考虑浆液黏度空间分布不均匀性时,孔口注浆终压计算值为试验值的1.2~1.4倍,浆液扩散距离计算值为试验测量值的0.9~1.1倍,计算值与试验值的误差在可接受范围内,所创建的理论模型可较好地描述速凝浆液一维渗透注浆扩散过程。不考虑浆液黏度空间分布不均匀性时,孔口注浆终压计算值为试验值的3.5~4.1倍,浆液扩散距离计算值为试验测量值的0.5~0.7倍,显著高估了注浆压力、低估了浆液扩散范围。因此,在注浆设计中应充分考虑速凝浆液黏度空间分布不均匀性。

Time-dependent behavior of viscosity of quick setting slurry and double liquid grouting mode lead to spatial uneven distribution of viscosity in diffusion region. The influence of spatial uneven distribution of viscosity should be considered in permeation grouting diffusion model of quick setting slurry. By regarding quick setting slurry as a Bingham liquid of time-dependent behaviour, an even capillary group model is used to describe porous flow process. A theoretical model of one-dimensional permeation grouting is developed under constant grouting rate. A visual permeation grouting simulation test system is designed to obtain the permeation rates of different media and the relationship between grouting pressure and grouting time for cement-sodium silicate（C-S） slurry. Results show that： when the spatial uneven distribution of viscosity is considered, the calculated value of grouting pressure is 1.2-1.4 times the test value and the calculated value of grouting distance is 0.9-1.1 times the test value. The theoretical and experimental results are in good agreement. The proposed model can well describe the process of one-dimensional permeation grouting of quick setting slurry. When the spatial uneven distribution of viscosity is not considered, the calculated value of grouting pressure is 3.5-4.1 times the test value and the calculated value of grouting distance is 0.5-0.7 times the test value. So the grouting pressure is overestimated significantly and the grouting distance is underestimated. The spatial uneven distribution of viscosity should be considered carefully in grouting design.