基于赫巴流体的盾构同步注浆三维扩散机理

The complex geological environment and diverse excavation sections in a shield tunnel pose challenges in grouting control. This paper investigates 3D diffusion mechanism of synchronous grouting in shield tunnel, using Herschel -Bulkley fluid constitutive model. A theoretical model was proposed to describe the filling diffusion and permeation diffusion processes, and derives the corresponding calculation formulas for each. It was verified by engineering examples and grouting test results. Additionally, a parametric analysis was conducted on key factors, such as grout density, shield tail void thickness, grouting pressure, grouting rate, and stratum permeability coefficient. The results show that in the circumferential filling stage, the dissipation rate of the grout at the grouting hole decreases with the increase of grout density, while the shield tail void thickness has minimal effect. In the axial filling stage, the slurry filling pressure dissipates over time, with the dissipation rate of grout gradually decreases as the shield tail void thickness increases. In the radial permeation stage, the permeation depth of the grout increases with the increase of permeability and grouting pressure, while grout density and shield tail void thickness have minimal effect.