Volume of fluid method based finite element analysis of fracture grouting

Fracture grouting is an effective method for soil reinforcement, yet the theoretical studies are far behind engineering practice. Using secondary-developed ABAQUS, a finite element model of fracture grouting is proposed based on the smeared crack model and VOF (volume of fluid) method. Results of FEM analysis are in good agreement with the laboratory tests. The effects of grouting depth and injection rate on the grout vein shapes are then investigated. The results show that fracture process can be divided into two stages: fracture initiation and extension. When the grout veins reach model boundary, higher grouting pressure is needed to increase the width of grout veins. With the grouting depth increases, the grout veins have less branches, reducing length and increasing width. The main factors affecting the shape of grout veins change from randomness of soil properties to the difference between major and minor principle stress. For given injection volume, higher injection rate results in shorter and thicker grout veins and higher grouting pressure. The research provides theoretical support for engineering applications of fracture grouting.