EVALUATION OF SUPER WELL POINT AS GROUND IMPROVEMENT METHOD FOR SOFT SOILS

Abstract

This thesis aims to evaluate the efficacy of Super Well Point (SWP) on consolidating soft soil through physical modelling, analytical studies and field trial. A large-scale laboratory unit cell test investigates the differences in soil behaviour when subjected to SWP and vacuum preloading (VP). It was found that SWP induced a faster pore water pressure dissipation than VP; hence, this proved that SWP could consolidate soft soil. Centrifuge modelling was employed to characterize the pore water pressure’s dissipation pattern in the soil layer during SWP treatment. The pore water pressure’s boundary condition of an SWP unit cell model was proposed through the centrifuge model test. An analytical model was derived based on the proposed boundary condition to estimate the average degree of soft soil consolidation under SWP treatment. Lastly, the increment in surface settlement and undrained shear strength observed from the field-scale SWP trial validated the feasibility of this method.