Diffusion Mechanism and Parameters Acquisition of Quasirectangular Shield Synchronous Grouting using SPH Method

Abstract:

Due to the particularity of heterotype shield, further research need to be executed on grouting diffusion effect and control parameters. This diffusion mechanism and parameter acquisition were studied using smoothed particle hydrodynamics (SPH) for the first quasirectangular shield tunneling project in China. The results show that the grout diffusion pattern has an related squeezing filling property in longitudinal and ring direction, and its filling efficiency is poor at top/bottom of the shield; The grout diffusion surface curvature, grouting pressure loss rate, entire flow sealing efficiency and filling uniformity of rectangular grout are better than these situation of liquid grout and thick grout; The disturbance degree of 150% injection rate for the surrounding stratum environment is minimal, and the optimum effect with grout injection ratio is 4∶3∶2∶1, which reflects in pressure distribution is more uniform; And considering the filling time, it is suggested that the symmetrical hole position is more suitable for synchronous grouting.

Key words:quasi-rectangular shield; smoothed particle hydrodynamics(SPH) method; numerical simulation; synchronous grouting; diffusion mechanism; parameters acquisition