Experimental Study of Polyurethane Grout Diffusion in a Water-Bearing Fracture

Abstract

Polyurethane grouting can be used for antiseepage and reinforcement in underground construction. Understanding the diffusion characteristics of polyurethane grout is critical for good grouting design. However, the influence of water pressure on the diffusion of polyurethane grout is not clear. The aim of this work is to experimentally investigate the diffusion behavior of polyurethane grout in a water-bearing fracture. A series of laboratory experiments was conducted using a self-designed visual fracture grouting device under different conditions. The influences of grouting quantity and water pressure on grout diffusion distance and flow field are discussed. The results show that grout expansive diffusion and the pressure field change of the grout–water system have a phased characteristic. Also, the change of grout pressure is not synchronized with grout diffusion distance. The grout diffusion radius increases with the increase of grouting quantity, but decreases with the increase of hydrostatic pressure. The study helped gain insight into the performance of polyurethane grouting in fracture under static water condition.