Installation and Axial Pullout of Suction Caissons: Numerical Modeling

We outline the development of a computational procedure for finite-element analysis of suction-caisson behavior, highlighting its unique features and capabilities. The procedure is based on a description of clayey soil as a two-phase medium: a water-filled porous solid. Nonlinear behavior of the solid phase is represented by means of a bounding-surface plasticity model. An algorithm is developed for frictional contact in terms of effective normal stress. Furthermore, a special remeshing scheme is introduced facilitating the simulation of the installation process, tracking the caisson penetration path and avoiding numerical complications in the vicinity of the caisson-soil interfaces. To illustrate the use of the proposed computational procedure and examine its validity, complete simulations of available laboratory tests on model suction caissons are conducted. Results are presented and discussed for test-bed preparation (consolidation) followed by caisson installation by self-weight and suction, setup (reconsolidation), and axial pullout. The overall agreement between computations and measurements is good. Possible improvements are identified and recommendations are made regarding future studies.