Experimental study on the bearing capacity of large-diameter monopile in sand under water flow condition

Abstract

This paper presents the results of a series of laboratory studies to explore the effects of water flow on the bearing capacity of monopiles in sand. The load-displacement relationship, axial force, normalized bending moment of the pile shaft, the p–y curves and the bearing envelope are obtained to quantify the effect of water flow on the bearing capacity of the monopile. The results demonstrate that water flow can result in a maximum scouring depth of 0.7 D (pile diameter), which reduces the lateral bearing capacity by about 4–10%. It is also found that the bearing capacity of the pile for resisting eccentric lateral load (equals to moment and horizontal loads at mudline) slightly increases at the initial stage with the rise of the applied vertical load. Finally, the bearing capacity envelopes of pile with and without water flow are proposed, which can provide guidance for the design of monopiles.