Estimation of lateral displacement induced by jet grouting in clayey soils

Abstract

The installation of jet-grouted columns in soft ground can induce lateral displacement resulting from injection of a great amount of water and grout into the ground, which may then lead on to further significant effects. This paper presents an approach to estimate the lateral displacement due to the installation of a jet-grouted column in clayey soils. Assuming that the installation of a jet-grouted column is represented by the expansion of a cylindrical cavity with a uniform radial stress applied at the plastic–elastic interface in a half-plane, the analytical solution developed by Verruijt is adopted in this study to calculate the lateral displacements attributable to the expansion of the cylindrical cavity. An empirical equation that accounts for the jetting parameters (jetting pressure, flow rate of the fluid and rod withdrawal rate) and soil properties (soil type and its undrained shear strength) has been developed to determine the radius of the plastic zone. Three case histories analysed in this paper demonstrate that the proposed method can be used for estimation of the lateral displacement caused by installing jet-grouted columns in clayey soils, despite minor discrepancies from the group column installation case between the predicted and measured values. These minor discrepancies can most likely be attributed to the omission of the effect of installation sequence and rheological properties of the grout in the calculation.