Effect of Pile Bending Stiffness on Static Lateral Behavior of a Short Monopile in Dry Sand

Authors

1 Phd candidate, university of Tehran

2 Associate professor, university of Tehran

3 Assistant professor, university of Tehran

Abstract

Monopiles are common foundations for offshore structures such as wind turbines and they are commonly used as fender piles in port structures. In such structures, especially in OWTs, the ratio of pile length to diameter (L/D) is small which makes the pile behave as a rigid structure. However, the pile flexural (bending) stiffness still affects the pile load-displacement characteristics and maybe should not be ignored in the pile design. In this study, the effect of pile flexural stiffness on a short monopile subjected to static lateral load is investigated.  The modeled pile has aspect ratio of 5 (L/D=5) which is driven into medium sand. The main characteristics of pile static lateral behavior including lateral resistance, stiffness, deflections, bending distribution and toe-kick are investigated and results are discussed. Results show that in the studied case, the pile behavior pattern is in the middle of flexible and completely rigid pile and therefore bending stiffness has meaningful effects on some important parameters related to monotonic performance.

Keywords


[1] ABAQUS 6.14 User Manual [2] API, American Petroleum Institute (2005), Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms—Working Stress Design-RP 2A (WSD) [3] Byrne, B. (2011). “Foundation Design for Offshore Wind Turbines.” Géotechnique Lecture, University of Oxford [4] Cuéllar, P. (2011). “Pile foundations for offshore wind turbines: numerical and experimental investigations on the behaviour under short-term and long term cyclic loading.” Ph.D. thesis, University of Technology Berlin, Germany. [5] Harry_G._Poulos,_Edward_H._Davis. , Pile foundation analysis and design, Series in geotechnical engineering, 1980 [6] Klinkvort R.T., Hededal O. (2014). “Effect of load eccentricity and stress level on monopile support for offshore wind turbines.” Can. Geotech. J. 51: 966–974 (2014) dx.doi.org/10.1139/cgj-2013-0475 [7] Rosquoët, F., Thorel, L., Garnier, J., and Canepa, Y. (2007). “Lateral cyclic loading of sand-installed piles. Soils and Foundations.” 47(5): 821–832. doi:10.3208/sandf. 47.821. [8] Ahmadi M. M., Paydar N. A., “Requirements for soil-specific correlation between shear wave velocity and liquefaction resistance of sands,” Soil Dynamics and Earthquake Engineering 57(2014)152–163