Centrifuge Modeling of Monotonic and Cyclic Lateral Behavior of Monopiles in Sand

This paper presents a program of centrifuge model tests (100g) on the monotonic and cyclic lateral loading behavior of monopiles. The diameter and burial depth of the model pile were 59 and 550 mm, respectively, and the soil used was Fujian sand with a relative density of 70%. During monotonic loading, a linear relation between the lateral soil resistance and the pile deflection was observed, with the slope increasing linearly with soil depth. For the sand sample used in this study, the loading rate had a surprisingly weakening effect on the lateral pile-soil interaction. This was confirmed by the development of positive excess pore pressure (EPP) and the contraction behavior observed in triaxial tests. During cyclic loading, the EPP oscillated at a constant amplitude, without any accumulation with the number of cycles, and the relation of the oscillation amplitude to pile deflection velocity was derived. Implications for practice in the field when assessing the lateral pile-soil interaction of monopiles considering EPP development characteristics were discussed. (C) 2021 American Society of Civil Engineers.