A New Associative Yield Function for Suction-Embedded Plate Anchors in Undrained Clay

This study proposes a new associative yield function (f*) for suction-embedded plate anchors in undrained clay, addressing the limitations of the commonly used yield function (f). Firstly, 2,520 three-dimensional finite-element simulations were conducted to evaluate the capability of f in two key aspects: (1) accurately fitting the anchor failure envelope under V-H-M combined loadings, and (2) enabling associated flow. For the latter, a novel method for measuring anchor plastic velocity is proposed based on specific features of the anchor’s ultimate state, allowing for a direct inspection of the associativity (normality) of anchor plastic velocity. Results suggested the fitting and associativity of f deteriorate as M increases or embedment decreases. To mitigate these issues, a novel algorithm, combining a genetic algorithm to find the optimal mathematical form and linear regression to determine the optimal parameters, is proposed to identify a more effective yield function. The resulting yield function f* demonstrates improved associativity and better fit to the failure envelope compared with f. Further comparisons of their performances were made in retrospective macroelement simulations against large-deformation finite-element (LDFE) modelings. Function f* showed satisfactory agreement with LDFE results without requiring user intervention (back-analysis), whereas f performed unsatisfactorily.