Behavior of helical piles - as a geoenvironmental choice - by frustum confining vessel (FCV)
Treść / Zawartość
Helical piles are environmental friendly and economical deep foundations that due to environmental considerations are excellent additions to the variety of deep foundation alternatives available to the practitioner. Helical piles performance depends on soil properties, the pile geometry and soil-pile interaction. Helical piles can be a proper alternative in sensitive environmental sites if their bearing capacity is sufficient to support applied loads. The failure capacity of helical piles in this study was measured via an experimental research program that carried out by Frustum Confining Vessel (FCV). FCV is a frustum chamber by approximately linear increase in vertical and lateral stresses along depth from top to bottom. Due to special geometry and applied bottom pressure, this apparatus is a proper choice to test small model piles which can simulate field stress conditions. Small scale helical piles are made with either single helix or more helixes and installed in fine grained sand with three various densities. Axial loading tests including compression and tension tests were performed to achieve pile ultimate capacity. Results indicate the helical piles behavior essentially depends on pile geometric characteristics, i.e. helix configuration and soil properties. According to the achievements, axial uplift capacity of helical model piles is about equal to usual steel model piles that have the helixes diameter. Helical pile compression bearing capacity is too sufficient to act as a medium pile, thus it can be substituted other piles in special geoenvironmental conditions. The bearing capacity also depends on spacing ratio, S/D, and helixes diameter.
Bibliogr. 22 poz., fig., tab.
- 1. Basu, P., and Prezzi, M., (2009), “Design and Applications of Drilled Displacement(Screw) Piles”, Publication FHWA/IN/JTRP-2009/28., Joint Transportation Research Program, Indiana Department of Transportation and Purdue University, West Lafayette, Indiana, doi: 10.5703/1288284314278.
- 2. Perko, H. A., (2003), “Lateral Capacity and Buckling Resistance of Helix Pier Foundations”, Foundations Technology Seminar-Helical Foundations and Tiebacks, Deep Foundation Institute, Helical Pile Committee, University of Cincinnati, Cincinnati, OH.
- 3. Vito, D., and Cook, T., (2011), “Case histories on the use of helical piles for retrofitting and new construction”, 2011 Pan-Am C-G-S, Geotechnical Conference, Canada.
- 4. Kurian, N. P. and Shah, S.J., (2009), “Studies on the Behavior of Screw Piles by the Finite Element Method”, Can. Geotech. J. 46, pp 627-638, Published by NRC Research Press.
- 5. Davis, R., (2009), “The helical pier defined”, (http:// www. Helicalpierworld.com/ archives/ hpdefinition.aspx), July 13, 2009.
- 6. Sakr, M., (2011), “Installation and Performance Characteristics of High Capacity Helical Piles in Cohesionless Soils”, DFI Journal Vol.5 No.1, pp 39-57, June 2011.
- 7. Perko, H., A. (2009),”A Practical Guide to Design and Installation”, John Wiley & Sons, Inc, Hoboken, NJ, USA.
- 8. Pack, J.S., (2009) , “Practical Design and Inspection Guide for Helical Piles and Helical Tension Anchors”, I.M.R., Inc., Denver, Colorado, Revision 2, U.S.A.
- 9. Willis, D., (2009), “How to Design Helical Piles per the 2009 International Building Code”, Ram Jack Foundation Solution, USA.
- 10. Choi, Y., Kim, D. C., Kim, S. S., Nam, M. S., and Kim, T. H., (2013), “Implementation of Noise-Free and Vibration-Free PHC Screw Piles on the Basis of Full-Scale Tests”, J. Constr. Eng. Manage. 2013.139:960-967.
- 11. Hoyt, R.M. and Clemence, S.P., (1989), “Uplift Capacity of Helical Anchors in Soil”, Proceedings of the 12th International Conference on Soil Mechanics and Foundation Engineering, Vol. 2, pp.1019-1022.
- 12. Sakr, M. (2009), “Performance of Helical Piles in Oil Sand”, Can. Geotech. J. 46, pp 1046-1061, Published by NRC Research Press.
- 13. Canadian Geotechnical Society, (2006), “Canadian Foundation Engineering Manual”, CFEM, 4th edition, published in Canada.
- 14. Tappenden, K., Sego, D. and Robertson, P., “Load Transfer Behavior of Full-Scale Instrumented Screw Anchors”, Contemporary Topics in Deep Foundation, ASCE, 2009.
- 15. Sprince, A. and Pakrastinsh, L., (2010),“Helical Pile Behavior and Load Transfer Mechanism in Different Soils”, Modern Building Materials, Structures and Techniques, The 10th International Conference, pp 1174-1180.
- 16. Di Bernardo, G. (2012),“Helical Pile Deck Foundation”, New Jersey Deck Boulder, USA.
- 17. Livneh, B. and El Naggar, M.H., (2008), “Axial Testing and Numerical Modeling of Square Shaft Helical Piles under Compressive and Tensile loading”, Canadian Geotechnical Journal, Vol. 45, pp.1142–1155.
- 18. Sedran, G. (1999),” Experimental and Analytical Study of a Frustum Cnfining Vessel”, A thesis Submitted to the School of Graduate Studies in Partial Fulfïlment of the Requirements for the Degree Doctor of Philosophy, McMaster unv, Canada
- 19. Zare, M. and Eslami, A. (2014),“Study of Deep Foundations Performance by Frustum Confining Vessel (FCV)”, International Journal of Civil Engineering (IJCE), IUST University, Tehran, Iran.
- 20. Horvath, R.G. and Stolle, D., (1996), “Frustum Confining Vessel for Testing Model Piles”, Can. Geotech. J. 33, pp 499-504, Printed in Canada.
- 21. Sakr, M. (2010),“High Capacity Helical Piles – A New Dimension for Bridge Foundations”, Proceedings of 8th International Conference on Short and Medium Span Bridges, Niagara Falls, Canada, 2010.
- 22. Merifield, R. S. (2011),“Ultimate Uplift Capacity of Multiplate Helical Type Anchors in Clay”, Journal of Geotechnical and Geoenviromental Engineering, ASCE, pp 704-712.