Theoretical analysis of cavity expansion for compaction grouting in saturated clay under non-Darcy seepage

Abstract:

To investigate the mechanical response of soil caused by the expansion of cavity under the action of seepage in the process of soft soil grouting, based on the generalized Tresca yield criterion and the non-correlated flow criterion, the elastoplastic solution to the problem of cavity expansion of grouting in saturated soft clay was derived combined with the elastoplastic boundary conditions in consideration of the comprehensive effects of nonlinear seepage and strain softening factors. The differences of the calculation results of seepage field, stress field, and displacement field of the soil around the cavity with or without considering the action of seepage were compared and analyzed through calculation examples, and the influence of the nonlinear seepage coefficient m was further discussed. Results show that the radius of the plastic zone and the radial stress in the high-speed nonlinear seepage mode were both smaller than those under the Darcy linear seepage state, and the greater the degree of nonlinearity was, the smaller the value was. The radial displacement was less affected by the nonlinear seepage coefficient m, and it was basically the same in the two modes. Hence, the influence of non-Darcy seepage of groundwater on the cavity expansion pressure should not be underestimated. When studying such problems in the future, the influence of different seepage states should also be fully considered, so that the calculation results are closer to the actual situation.Symbol`@@