不同渗透系数的非均质黏土劈裂注浆数值模拟

Numerical simulation of split grouting of heterogeneous clay with different permeability coefficient

针对地下工程中软弱黏土地层病害治理问题,考虑黏土材料的非均质性与低渗透性,对黏土进行劈裂注浆加固特性分析。基于Weibull分布函数理论构建非均质黏土地层模型,对黏土进行劈裂注浆加固模拟;基于注浆模拟计算结果,分析不同均质度与渗透系数对黏土劈裂注浆效果的影响。结果表明:土体劈裂注浆难度随均质度的增大而增加,均质度较高土体劈裂后产生的裂缝较为单一,裂缝分布范围较小;均质度较低土体劈裂产生的裂缝宽度较大,裂缝影响范围更广。浆脉扩展的长度及增长幅度随土体渗透系数的增大而减小,高渗透系数土体的劈裂浆脉宽度要大于低渗透系数的土体,渗透系数较小土体的浆脉长度始终比较大,浆脉距注浆孔越远,其宽度越小。研究可为软弱黏土地层劈裂注浆的工程应用提供指导。

Considering the heterogeneity and low permeability of the clay materials, the fracture grouting reinforcement characteristics of the clay are analyzed in view of the disease treatment of soft clay stratum in underground engineering.Based on Weibull distribution function theory, a heterogeneous clay formation model was constructed, and the clay was simulated by splitting grouting. Based on the results of grouting simulation, the influence of different uniformity and permeability coefficients on the grouting effect of clay splitting was analyzed. The results show that the difficulty of splitting grouting increases with the increase of the uniformity of soil mass, and the crack produced by splitting of soil mass with higher uniformity is relatively single and the distribution range of crack is smaller. The crack width is larger and the influence range is wider when the soil is less homogeneous. The length and growth amplitude of slurry vein expansion decrease with the increase of soil permeability coefficient. The width of slurry vein in the soil with a large permeability coefficient is larger than that in the soil with a low permeability coefficient. The length of slurry vein in the soil with a small permeability coefficient is always larger, and the farther the slurry vein is from the grouting hole,the smaller the width. The research has important guiding significance for the engineering application of fracture grouting in soft clay stratum.