Enhancing Pullout Load Capacity of Helical Anchor in Clay with Adjusted Load Application Point under Inclined Loading Condition

In this study, the effect of load application point (zp) on the load capacity (Qu) of helical anchors under inclined loading condition was investigated. For this purpose, coupled Eulerian-Lagrangian finite element analyses were performed for various configurations of helical anchor and load inclination angles (θ). The focus was on characterizing the optimum load application point that can most enhance the load capacity of helical anchors. Both inclined loading and load application point significantly affected the load capacity of the helical anchor. For the individual failure-mechanism case, the effect of θ on Qu was clearly beneficial in most cases, indicating that the individual configuration is more advantageous when a taut or catenary mooring type is adopted. The load capacity of the helical anchor increased as the load application point moved from the top to certain limit depth, below which the load capacity became reversely decreased with further increasing zp/L. The optimum loading depth was found at zp/L=0.625. The effect of zp on the pullout capacity was mainly controlled by the horizontal load component. Based on the results of this study, design equations for the load capacity of helical anchors with load application point are proposed.