Model tests and finite element analysis for the cyclic deformation process of suction anchors in soft clays

Abstract

More attentions have been focused on the ultimate bearing capacity rather than the cyclic deformation process of suction anchors under cyclic loads in previous researches. Few researches are reported about the finite element analysis for the cyclic deformation process of suction anchors in soft clays, because lacking the suitable constitutive model that can not only describe reasonably the cyclic stress-strain responses of soft clays but also can be easily implemented into 3D nonlinear finite element analysis codes. The cyclic deformation process of suction anchor subjected to the combined static and cyclic loads are investigated by conducting model tests under 1 g condition, and the cyclic behaviors are simulated using the finite element method based on the UMAT subroutine for an elastoplastic bounding surface model proposed by the authors. The predictions show that the cyclic deformation process of suction anchor in soft clays can be simulated well by using the constitutive model and setting appropriate finite element calculation parameters. The cyclic displacement-time history and load-displacement response of the suction anchor can be predicted by the finite element analysis and the predictions are in good agreement with the test results. The failure modes of anchors can be predicted well because the predicted displacement components along vertical and horizontal directions are basically consistent with the experimental results. In addition, the cyclic bearing capacity of anchors can also be determined according to appropriate displacement failure criterion.