A Discrete Element Method Centrifuge Model of Monopile under Cyclic Lateral Loads
This paper presents the data of a series of two-dimensional Discrete Element Method (DEM) simulations of a large-diameter rigid monopile subjected to cyclic loading under a high gravitational force. At present, monopile foundations are widely used to support the tall and heavy wind turbines, which are also subjected to significant from wind and wave actions. A safe design must address issues such as rotations and changes in soil stiffness subject to these loadings conditions. Design guidance on the issue is limited, so are the availability of laboratory and field test data. The interpretation of these results in sand, such as the relation between loading and displacement, relies mainly on empirical correlations to pile properties. Regarding numerical models, most data from Finite Element Method (FEM) can be found. They are not comprehensive, and most of the FEM results are sensitive to input parameters. The micro scale behaviour could change the mechanism of the soil-structure interaction. A DEM model was used in this paper to study the cyclic lateral loads behaviour. A non-dimensional framework is presented and applied to interpret the simulation results. The DEM data compares well with various set of published experimental centrifuge model test data in terms of lateral deflection. The accumulated permanent pile lateral displacements induced by the cyclic lateral loads were found to be dependent on the characteristics of the applied cyclic load, such as the extent of the loading magnitudes and directions.
Doherty, P. and K. Gavin Laterally loaded monopile design for offshore wind farms. Proceedings of the ICE - Energy, 2012. 165, 7-17.
 API, Recommended Practice for Planning, Designing, and Constructing Fixed Offshore Platforms, in Working Stress Design. 2007: American Petroleum Institute, Washington, DC, USA.
 Reese, L.C. and H. Matlock. Non-dimensional solutions for laterally-loaded piles with soil modulus assumed proportional to depth. 1956. Dallas, Tex.: Association of Drilled Shaft Contractors.
 Verdure, L., J. Garnier, and D. Levacher Lateral Cyclic Loading of Single Piles in Sand. International Journal of Physical Modelling in Geotechnics, 2003. 3, 17-28.
 Reese, L.C., W.R. Cox, and F.D. Koop. Analysis of laterally loaded piles in sand. in 5th Ann. Offshore Technology in Civil Engineering. 1974. Houston,Tex: ASCE.
 O'Neill, M.W. and J.M. Murchison, An evaluation of py relationships in sands. 1983: University of Houston.
 Long, J. and G. Vanneste, Effects of cyclic lateral loads on piles in sand. Journal of Geotechnical Engineering, 1994. 120(1): p. 225-244.
 Moss, R.E.S., J.A. Caliendo, and L.R. Anderson, Investigation of a cyclic laterally loaded model pile group. Soil Dynamics and Earthquake Engineering, 1998. 17(7–8): p. 519-523.
 Cundall, P.A. and O.D. Strack, A discrete numerical model for granular assemblies. Geotechnique, 1979. 29(1): p. 47-65.
 Cheng, Y.P., Micromechanical investigation of soil plasticity. 2004, Cambridge University.
 Itasca, PFC User Manual, version 3.1. 2004, Itasca Consulting Group Inc: USA.
 Klinkvort, R.T., Centrifuge modelling of drained lateral pile - soil response: Application for offshore wind turbine support structures, in Application for offshore wind turbine support structures, O. Hededal and S. Springman, Editors. 2013, Technical University of Denmark.
 Duan, N. and Y.P. Cheng, A Modified Method of Generating Specimens for 2D DEM Centrifuge Model, in Geo-Chicago 2016. 2016: Chicago. In press
 Schofield, A.N. Cambridge Geotechnical Centrifuge Operations. Géotechnique, 1980. 30, 227-268.
 Fuglsang, L.D. and N.K. Ovesen, The application of the theory of modelling to centrifuge studies, in Centrifuges in Soil Mechanics. 1988, Taylor & Francis: Abington, UK. p. 119–138.
 Randolph, M.F., The response of flexible piles to lateral loading. Geotechnique, 1981. 31(2): p. 247-259.
 Leblanc, C., Design of offshore wind turbine support structures: selected topics in the field of geotechnical engineering, in Department of Civil Engineering, A. Aalborg Universitet. Institut for Byggeri og, Editor. 2009, Department of Civil Engineering, Aalborg University.
 Leblanc, C., G.T. Houlsby, and B.W. Byrne, Response of stiff piles in sand to long-term cyclic lateral loading. Geotechnique, 2010. 60(2): p. 79-90.
 Roesen, H.R., et al. Laboratory Testing of Cyclic Laterally Loaded Pile in Cohesionless Soil. in The Twenty-third International Offshore and Polar Engineering Conference. 2013. International Society of Offshore and Polar Engineers.
 Li, Z., S.K. Haigh, and M.D. Bolton. Centrifuge modelling of mono-pile under cyclic lateral loads. in 7th International Conference on Physical modelling in Geotechnics. 2010. Switzerland.