砂土介质中颗粒浆液扩散距离变化规律

基于质量守恒方程、线性滤过定律、Darcy定律及边界条件,建立层流条件下颗粒浆液扩散距离的理论模型。采用自主研发的单体组配式渗透注浆装置,研究不同水灰比、不同流速条件下浆液扩散距离的变化规律,并将忽略渗滤理论值、考虑渗滤理论值、模型试验值进行比对分析。结果表明,恒定流速v0条件下,忽略渗滤效应的浆液扩散距离与实际不相符;浆液水灰比、注浆流速均与扩散距离呈正相关。水灰质量比1∶1时,模型试验值与考虑渗滤理论值偏差18.4~20.8 cm,偏差率68.9%~71.9%;水灰质量比2〓∶1时,模型试验值与考虑渗滤理论值偏差20.7~23.4 cm,偏差率27.0%~28.2%。研究成果可指导注浆钻孔间距设计,具有一定的工程应用价值。

Variation of granular slurry diffusion distance in sand medium

Based on the mass conservation equation, linear filtration law, Darcy's law and specific boundary conditions, a theoretical diffusion distance model of granular slurry under laminar flow conditions was established. By developing and applying an assembly-type device for permeating grouting, the diffusion rules of grout under different water-cement ratio and flow rate were studied. The value of model test was compared with the theoretical values when the filtration effect was considered or not. The results showed that when the flow velocity v₀ was constant, the theoretical diffusion distance without filtration effect considered was not consistent with reality. Both the water-cement ratio and velocity of grout were positively correlated with diffusion distance. When the water-cement ratio was 1∶1, the deviation between the value of model test and the theoretical calculation with filtration considered was 18.4 to 20.8 cm, with a deviation rate of 68.9% to 71.9%. When the water-cement ratio came to 2 ∶1, corresponding values were within 20.7 to 23.4 cm, and 27.0% to 28.2% respectively. The research results could guide the drilling spacing design of grouting and had some application value for project.