Effects of properties of surrounding rock on change laws of grouting pressures and diffusion patterns

The effects of properties of surrounding rock on grouting patterns of slurry diffusion and change laws of grouting pressure are studied by grouting simulation tests. The heterogeneity of practical surrounding rock is simulated by filling the soil with different void ratios into different parts of the model frame. Different stages of practical grouting are simulated by grouting through multiple grouting holes respectively. The diffusion patterns of grouting slurry are obtained by studying the grouting fractures and bulbs of different grouting holes. The change laws of grouting pressure are obtained by analyzing the grouting pressure data of different grouting holes. The effects of grouting on the void ratio and compression coefficient of the surrounding rock are obtained by testing the samples before and after grouting. The results show that the diffusion patterns of grouting slurry and the change laws of grouting pressure are closely related to the properties of the surrounding rock. By analyzing the diffusion patterns of grouting slurry or the change laws of grouting pressure, the properties of surrounding rock can be estimated so as to offer the basis for the improvement of the design of grouting parameters. The conclusions are verified by the curtain grouting project of Yonglian Tunnel.