A series of experiments of chemical grouting into a fracture with flowing water are carried out by using fracture grouting equipment based on orthogonal test design. The correlation among water plugging effect

seepage pressure variation

and grouting technology is obtained by analyzing the test results. The results show that the seepage pressure curves of grouting into a fracture with flowing water can be divided into four types

including single peak type

platform type

multi-peak type and ladder type. The water plugging effect is good when the seepage pressure curves are platform type and multi-peak type. It is poor for water plugging when the seepage pressure is ladder-type. In order to improve the water plugging effect and save the grout

the grout amount should be increased while the seepage pressure is peak type; but it should be decreased while the seepage pressures are platform type and multi-peak type; and the volume ratio of grout should be regulated to short gel time while the seepage pressure is ladder-type. The results can improve the efficiency and technology of grouting based on seepage pressure monitoring.