Numerical analysis of slurry flow in pile‐end grouting of the drilling with prestressed concrete pipes

Understanding the diffusion law of cement slurry is the key to analyzing and evaluating the reinforcement effect of grouting. This study aimed to reveal the flow grouting mechanism of slurry in the reserved space between piles and soil and the penetration diffusion rule of slurry in the soil around the piles. For this purpose, the grouting slurry was regarded as a Newtonian fluid. The Navier–Stokes equations of fluid mechanics and renormalization group k–ε model were used to study the flow diffusion of slurry in the reserved space around a pile for grouting the drilling with prestressed concrete pipes. The permeability of soil slurry was determined using Darcy's law, and the flow field of slurry during grouting was numerically simulated. The results showed that the flow velocity of slurry and the reinforcement effect of grouting decrease gradually as the flow path extends. The radial flow of slurry in the grouting pipe shows a clear trend of circumferential diffusion. The slurry thickness in the reserved space for grouting decreases with an increase in the distance from the grouting outlet. Its attenuation trend becomes more obvious with increasing grouting height. The grouting thickness directly reflects the filling effect of slurry and is an important index to evaluate the grouting effect of drilling with prestressed concrete pipes.