Estimation of Heave Due to Inclined Compaction Grouting

Compaction grouting is a ground improvement technique that involves injection of a thick-consistency soil-cement grout under high pressure into the soil mass, consolidating, and thereby densifying targeted soil in-place. This technique is often used to lift or re-level any settled or tilted structure. Inclined grout injection is necessary to perform grouting below any existing foundation. For an efficient inclined grouting operation, prior estimation of heave at the ground surface is important. In this study, we estimate the upheaval of the ground surface just above the inclined grout column based on the elastic continuum approach. Influence factors are derived for the estimation of ground heave. Using these influence factors, vertical displacements due to the radial pressure exerted by the grout column are estimated at different points. A parametric study is performed to investigate the effects of grout column length, depth of injection of grout and inclination of the grout column on the heave at the ground surface.