Rheological Consolidation of Partially Penetrated Deep Mixed Column-Reinforced Soft Soil under Rigid Foundation

Abstract

Deep mixed (DM) columns are being increasingly used in regions that host thick saturated soft clays. Under such geotechnical conditions, partially penetrated DM columns are predominantly designed to improve shallow foundations. Ground settlement can develop gradually over decades, however, due to the consolidation and rheological behavior of the subsoil. This work developed an analytical solution for calculating the rheological consolidation of partially penetrated DM-column-reinforced ground under a rigid foundation following the rheological Burger’s model. Based on the equal strain assumption, the consolidation problem was converted into a simple problem of one-dimensional consolidation with a double-layered system. The derived solution revealed that the reduction in column permeability to less than 10% of the soil permeability had a minor influence on the consolidation rate. The consolidation rate increased slowly with increasing penetration depth.