LAUSR

Abstract Numerical investigations of the whole installation process of giant deep-buried circular open (GDCO) caissons in undrained clay were conducted using 3D large deformation finite-element (LDFE) method performed by the Coupled Eulerian-Lagrangian (CEL) approach. This study was focused on the installation mechanism and soil deformation characteristics of GDCO caissons. A kinematic and continuous numerical technique based on the CEL approach accounting for the synchronous coupling between the penetration and excavation was first introduced to simulate real installation process of GDCO caissons. An advanced user-defined hypoplastic (HP) constitutive model was applied to match the clay behaviors realistically. The measured values of penetration resistance and ground surface settlement were compiled from centrifuge tests available to validate the proposed numerical technique and show the superiorities of HP model. The plastic zone, deformed soil flow, stress distribution and penetration resistance developed in clay were effectively captured to investigate the installation mechanism. Furthermore, the soil deformation including ground surface settlement and radial displacement around the caisson were examined. The simplified semi-empirical equations were then proposed to predict the ground surface settlement pattern and maximum value.