Full-Scale Axial Load Response of Jetted and Grouted Precast Piles in Cohesionless Soils

Jetted and grouted precast piles (JGPPs) are a newly developed urban-friendly deep foundation technique that employs water jetting for pile penetration and pressure grouting to enhance the axial and torsional resistance of precast piles. Previous experimental studies of JGPPs in a large test chamber setup have revealed that they can withstand very high axial loads; however, validation of the same in a typical field scenario was needed. This paper presents the pioneering study of the full-scale axial response of JGPPs in cohesionless soil condition. The study showed that JGPPs exhibit high skin and tip resistances under axial top-down loading. The paper also proposes a direct method to predict the ultimate skin resistance of JGPPs using the pressuremeter test results. The experimental results were compared with the values estimated using both the proposed and existing methods.