Abstract: Using a self-designed model of grouting penetration,the groutability and grouting reduced infiltration effect of chemical grout in weak cementation porous media is investigated.By controlling the different ratio of coarse and fine particles,permeability coefficient test and chemical grouting experiments of six different permeability models are completed.The results show that with the increasing of coarse granule contents in models,the permeability coefficient increases by exponential function before grouting;each model's leakage reduction effect is different after grouting,but overall leakage reduction effect from model 1 to model 4 is unsatisfactory.Under the test conditions,model 1to 4 were grouted by second time,and the effect is good.Through test the samples about natural water absorption and vacuum water absorption before and after grouting,the relationship between effect of reduction permeability of grouting and porosity is discussed.Analysis shows that the decline proportion of large open porosity reflected by natural water absorption after grouting is greater than the decreased degree of total porosity,which indicates that chemical grout has good filling effect for large pores with better connectivity.