Abstract: Based on the generalized Darcy’s Law and theory for spherical diffusion model, a formula for calculating the effective diffusion radius of exponential fluids injected into homogeneous sandy stratum in grouting is deduced . It shows that the grouting pressure difference is related to the grout rheology parameters c, n and the diffusion radius. The grouting pressure difference change with c by linearity rule and with n by nonlinearity rule. Grouting pressure difference increases with increasing radius, and the increasing grades are notably affected by the grout rheological parameters.

Key words: exponential grout, diffusion radius, penetration grouting, sand ground