ABSTRACT
The variation of grouting pressure has a significant impact on the internal force and deformation of adjacent segments, during synchronous grouting process of shield tunnel construction. To ensure the accurate control of grouting pressure and the safety for shield driving, the grout pressure space-time distribution along longitudinal direction of tunnel had been studied. Based on the study of grout viscosity time-variation, the process of grout diffusion and dissipation had been united. Considering the grout movement, the deformation formulas of tunnels along longitudinal direction had been obtained, with Winkler elastic foundation beam model. The result of theoretical calculation had been compared with field test data, and it shows that: the increase of grout viscosity and decrease of permeability of soil layers will affect the extent of grouting pressure dissipation, and then affect the deformation of tunnel segments. The result calculated from theoretical models are closer to field monitoring data when considering the time-varying effect of grout viscosity. The research provides a guideline for safety control of segment during construction.
