Abstract: During the installation of horizontal jet grout columns, the high pressurized fluids injected into the soil can induce the expansion of the foundation soils, causing significant movements of the soils around jet grouting locations. The soil deformation caused by installation of horizontal jet grout columns can be considered as the combined effects of the expansions induced by the high pressure and the volume of fluid. Based on a case history of the construction of horizontal jet grout column, a finite element model is developed for analysing the soil deformation caused by installation of horizontal jet grout columns. In this model, the soil deformation caused by installation of horizontal jet grout columns is simplified as the expansion of a round hole, the jetting pressure and the volume of injected fluids can be considered as a whole. A method is proposed to estimate the influencing radius of the jetting pressure, and the equations for determining the ratio of volume expansion are provided. Based on these, the soil deformation can be obtained by the finite element analysis. Comparisons of the measured values and numerical results indicate that the numerical results are in good agreement with the measured data when the influencing radius is 6 times that of the column, demonstrating the applicability of the developed finite element model.

Key words: horizontal jet grouting, soil deformation, numerical simulation, underground engineering