Four multiple grouting model tests have been finished with slurry tracked by different colors

by using typical porous sandstone selected in Ningdong. It reveals the law of diffusion and filling of slurry in pores

and the relationship between repetitions of grouting and permeability coefficient and porosity of the injected rock and soil mass. The studies found: the filling state of grout is obviously different from others in each single grouting of the multiple grouting test

the slurry of the first time grouting has more uniform filling in the entire profile

while the slurry shows accumulation of filling partly. In the experiment

the more the times of grouting is

the smaller the permeability coefficient of the model material and the greater the filling rate of pores will be. The relation between the permeability coefficient

filling rate of pores and number of repetitions of grouting can be fitted respectively by power function

and logarithmic function. The permeability coefficient of the model material is reduced by 97% after grouting for four times

which means that multiple grouting indeed has an influence on infiltration reduction. According to the test results

a numerical model is established to predict the water inflow of grouting holes and shaft with different grouting times and pore filling rate; and the water inflow of shaft is compared with the actual situation. The results are fairly consistent each other. showing that it is feasible to predict the water inflow by using numerical mode and basis of test results.