Effects of inner sleeves on the inner frictional resistance of open-ended piles driven into sand
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In open-ended piles, inner friction is developed between inner pile shaft and the inner soil. Inner frictional resistance depends largely on the degree of soil plugging, which is influenced by many factors including pile diameter, relative density and end conditions of piles. In this paper, effects of inner sleeves on inner frictional resistance are discussed. The experiments were conducted on a medium-dense sandy ground using laboratory-scale piles. It was observed that the piles penetrated under partially-plugged or unplugged state. The results suggest that inner frictional resistance, Qin increases with sleeve height, l linearly and requires 2D (D is pile outer diameter) of l to produce a large as 50% of Qt by Qin (Qt is total resistance). The results also indicate that bearing capacity increases with wall thickness at the pile tip, which can be attributed to the increase in annular area. The results also indicate that soil plug height is independent of sleeve height. The results also reveal that the penetration of straight piles is closer to unplugged state than the sleeved piles. The results of incremental filling ratio and plug length ratio also indicate that the degree of soil plugging is affected by the sleeve height.
Keywordsbearing capacity inner frictional resistance inner sleeve open-ended piles soil plugging
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- 1.Szechy C H. The effect of vibration and driving upon the voids in granular soil surrounding a pile. In: Proceedings of the 5th International Conference on Soil Mechanics and Foundation Engineering. Paris, France, 1961, 2: 161–164Google Scholar
- 2.Randolph M F, Steinfelt J S, Wroth C P. The effect of pile type on design parameters for driven piles. In: Proceedings of 7th European Conference on Soil Mechanics. London, England, 1979, 2: 107–114Google Scholar
- 4.Nauroy J F, Tirant L P. Model tests of piles in calcareous sands. In: Proceedings of the Conference on Geotechnical Practice in Offshore Engineering. Texas, United States, 1983, 356–369.Google Scholar
- 6.Tomlinson MJ. Pile Design and Construction Practice. London: E & FN Spon, 2004Google Scholar
- 7.Kikuchi Y. Mechanism of inner friction of an open-ended pile. In: Proceedings of the 3rd IPA International Workshop (Press-in Engineering 2011). Shanghai, China, 2011, 65–83Google Scholar
- 11.JRA. Specifications for highway bridges. Japan Road Association (JRA), Tokyo, Japan, 2002 (in Japanese)Google Scholar
- 12.Jardine R J, Chow F C. New Design Methods for Offshore Piles. London: MTD publication, 1996Google Scholar
- 13.API. Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms–Working Stress Design. American Petroleum Institute (API), Washington, USA, 2005Google Scholar
- 14.Lehane B M, Schneider J A, Xu X. A review of design methods for offshore driven piles in siliceous sand. Perth, Australia, UWA Report No. GEO, 2005, 05358: 683–689Google Scholar
- 16.Hettler A. Approximation formulae for piles under tension. In: Proceedings of IUTAM Conference on Deformation and Failure of Granular Materials. Delft, Netherlands, 1982, 603–608Google Scholar