Numerical simulation of the influences of different heterogeneity coefficients on the soil grouting fracturing processes

Abstract

Soft clay foundation is easy to produce uneven settlement, which threatens the safety of hydraulic structures. Clay consolidation grouting is an effective means to improve its mechanical properties, but the traditional finite element method and discrete element method have limitations in dealing with the splitting process of clay grouting. In order to investigate the cracking mechanism of clay grouting, a meshless numerical method was established to simulate the development process of soil grouting splitting veins, in the SPH framework, the “soil particles” and “slurry particles” are defined, and the interaction between “slurry particles” and “soil particles” under grouting pressure is deduced. A fracture marker κ, which can reflect the failure of particles, is introduced, which can simulate the progressive expansion of soil grouting splitting cracks. Considering the heterogeneous characteristics of soil, Weibull distribution function is introduced to consider the heterogeneous distribution of tensile strength, and the soil grouting splitting characteristics under different heterogeneous characteristics are numerically simulated. The result show that the improved SPH method can well simulate the development process of slurry veins during clay grouting splitting. The above implementation fully demonstrates that: When the soil heterogeneity is not considered, the extension shape of slurry veins is single and symmetrical, while when the soil heterogeneity is considered, the soil grouting fracturing shape is more complex, forming a criss-cross network of slurry veins. The soil disturbance caused by grouting is mainly concentrated in the vicinity of the grouting hole before the grouting pulse cracking, but after the grouting pulse cracking, the soil along the grouting pulse is greatly disturbed. Finally, the formation mechanism of soil grouting fracturing fracture is discussed. It is found that soil grouting fracturing bifurcation is caused by soil heterogeneous characteristics, and the application prospect of SPH in soil grouting fracturing simulation is prospected. Future research should focus on the development of 3D high-performance parallel SPH algorithm.

Keywords

fracture marker / soil grouting fracturing / fracture morphology / non-uniform distribution / numerical simulation