Abstract: In order to determine the failure criterion of suction anchors with taut mooring systems in soft clay, load-controlled and displacement-controlled model tests are conducted to study the bearing capacities of suction anchors with taut mooring systems under static load at the optimal loading point using an electric servo loading apparatus developed by the authors. The results show that the displacement along the mooring direction is about 0.6 times the diameter of anchor when the failure mode of anchor is vertical pullout; and the displacement along the mooring direction is about 0.3 times the diameter of anchor when the failure mode of anchor is lateral failure. At the same time, the bearing capacities of suction anchors are determined in terms of the failure criterion by model tests. The predicting results of limit analysis are basically in agreement with the results of model tests. Furthermore, it verifies the rationality of displacement failure criterion by the comparison of calculated results between finite element analysis and limit analysis on the full-scale anchors.

Key words: suction anchors, model tests of suction anchors, failure modes of anchor, displacement failure criterion, finite element analysis, limiting equilibrium analysis, upper bound plasticity analysis