Abstract: The circular tube grouting test was made by the established model of grouting slurry tube in rock mass and using piston type grouting pump commonly used in grouting engineering. The test results indicate that grouting pressure and grouting amount in unit time increase with the increase of the transmission velocity of the grouting pump. However, at the same velocity, the grouting pressure will increase with the decrease of the groutability of rock mass. The grouting pressure formed by cement type suspensoid is greater than that by high molecular chemical slurry. The effect of grouting pump, material or rock mass condition on the grouting pressure is mutually affected and mutually restricted. It is not merely an active representation of grouting pump power but a passive representation restricted by several factors such as rockmass condition and grouting material.

Key words: Grouting pressure, Rock mass, Circular tube model, Groutability