Failure mechanism and lateral bearing capacity of monopile-friction wheel hybrid foundations in soft-over-stiff soil deposit
Yikang Wang, Xinjun Zou, Mi Zhou, Xihong Zhang
Abstract
Experimental and numerical studies are carried out to explore the lateral load and moment resistance capacities of the monopile-friction wheel hybrid foundation in soft-over-stiff soil deposit. Model tests are firstly conducted to preliminarily investigate the soil failure mechanism of hybrid foundation under lateral eccentric load (lateral loading at a certain height above the seabed), which is followed by full model tests conducted to investigate the lateral load and moment resistance behaviors of the monopile-friction wheel hybrid foundation under static horizontal loading in soft-over-stiff soil deposit. A numerical model is then generated and validated with the laboratory testing results. Parametric study is performed to quantify the lateral bearing capacity of hybrid foundation in clay-over-sand soil deposits. Both the experimental tests and numerical simulations show that compared to conventional monopiles the hybrid system can provide a higher lateral bearing capacity and a larger lateral stiffness. The bearing capacity is found to be mainly influenced by the diameter of wheel Dw, undrained shear strength of clay su, loading eccentricity e and clay layer thickness Tc. Finally, empirical design formulae are proposed to estimate the lateral bearing capacity of the monopile-friction wheel hybrid foundation system under static horizontal loading in soft-over-stiff soil deposit.