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Simulation of monopile-wheel hybrid foundations under eccentric lateral load in sand-over-clay

  • Zou, Xinjun (College of Civil Engineering, Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education, Hunan University) ;
  • Wang, Yikang (College of Civil Engineering, Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education, Hunan University) ;
  • Zhou, Mi (School of Marine Science and Engineering, State key laboratory of subtropical building science, South China University of Technology) ;
  • Zhang, Xihong (School of Civil and Mechanical Engineering, Curtin University)
  • Received : 2021.01.09
  • Accepted : 2022.02.12
  • Published : 2022.03.25

Abstract

The monopile-friction wheel hybrid foundation is an innovative solution for offshore structures which are mainly subjected to large lateral eccentric load induced by winds, waves, and currents during their service life. This paper presents an extensive numerical analysis to investigate the lateral load and moment bearing performances of hybrid foundation, considering various potential influencing factors in sand-overlaying-clay soil deposits, with the complex lateral loads being simplified into a resultant lateral load acting at a certain height above the mudline. Finite element models are generated and validated against experimental data where very good agreements are obtained. The failure mechanisms of hybrid foundations under lateral loading are illustrated to demonstrate the effect of the friction wheel in the hybrid system. Parametric study shows that the load bearing performances of the hybrid foundation is significantly dependent of wheel diameter, pile embedment depth, internal friction angle of sand, loading eccentricity (distance from the load application point to the ground level), and the thickness of upper sandy layer. Simplified empirical formulae is proposed based on the numerical results to predict the corresponding lateral load and moment bearing capacities of the hybrid foundation for design application.

Keywords

Acknowledgement

The first three authors of this paper were financially supported by the National Natural Science Foundation of China (Grant No. 52178329, 51578231 & 42176224), Guangdong Basic and Applied Basic Research Foundation (2021A1515010828) and Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology (2021B1212040003).

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