Numerical and Experimental Research on Diffusion Characteristic of Polymer Slurry in Narrow Slot at Constant Pressure

To determine the diffusion behavior of a polymer slurry in a narrow slot under a constant pressure head, a relevant simulation model was established based on the theory of a time-varying viscosity, and a visual narrow-slit polymer grouting diffusion model experiment under constant-pressure-head conditions was conducted to verify the accuracy of the established numerical model. On this basis, the effects of the grouting volume, lifting speed, and pressure head on the slurry diffusion behavior (diffusion distance and pressure distribution) were analyzed using the central composite design scheme (response surface method). The results showed that (1) the slurry diffusion range first rapidly increased with increasing grouting volume and then stabilized; (2) with increasing lifting speed of the grouting pipe, the slurry diffusion range first rapidly decreased and then stabilized. when the grouting volume is 0.06 m3, the hydraulic pressure is 0 MPa, the lifting speed is 0 m/s, and the maximum slurry diffusion area is 2.81 m2.; and (3) at the initial stage of the test, the grouting diffusion pressure slowly increased with increasing lifting speed. At the later stage of the test, with increasing lifting speed, the grouting pressure first rapidly increased and then stabilized.