Axial bearing capacity of helical piles in moist and saturated conditions using frustum confining vessel (FCV)

Document Type : Research


1 PhD Candidate, Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Assistant Professor, Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

3 Professor, Department of Civil and Environment Engineering, Amirkabir University, Tehran, Iran


Due to the increasing demand in construction and use of different types of piles on the one hand and the high cost of conducting large-scale tests on different types of piles, on the other hand, new methods have been proposed to study the behavior of different types of piles. Physical modeling provides the researcher the capability of studying model piles in the scaled environment at low costs. Among the different methods of physical modeling, the use of frustum confining vessels (FCV) has gained attraction in recent years. FCV is a cone-shaped vessel that can produce a stress distribution similar to the idealized linear stress distribution in depth. Helical piles are common types of deep foundations which were first used about 200 years ago. Helical Apiles are driven to the soil by applying a torque to the end of piles in the presence of vertical loads. Their quick and noise-free installation method, the minimal disturbance during the installation, and  environmental compatibility make them popular for working in urban areas. In this research, using the finite element method, the optimal dimensions of FCV apparatus were selected, and the FCV apparatus with optimal dimensions were constructed. A total of 18 compression tests were performed on Anzali sand in different relative densities and moisture contents, using single-helix and three-helices piles. Results indicate that increasing the number of helices and relative density of soil increases the pile and sand contact and causes higher bearing capacity for helical piles. Soil saturation, on the other hand, significantly reduces the ultimate strength.


Main Subjects

[1] M. Sakr, A. Nazir, W. Azzam, and A. Sallam, "Model study of single pile with wings under uplift loads," Applied Ocean Research, vol. 100, 2020.
[2] S. N. Rao, Y. V. S. N. Prasad, and M. D. Shetty, "The Behaviour of Model Screw Piles in Cohesive Soils," Soils and Foundations, vol. 31, pp. 35-50, 1991.
[3] L. P. Andina Sprince, "Helical pile behavior and load transfer mechanism," presented at  The 10th International Conference, Vilnius, Lithuania, 2010.
[4]A. Eslami and B. H. Fellenius, "Pile capacity by direct CPT and CPTu methods applied to 102 case histories," Canadian Geotechnical Journal, vol. 34, p. 19, 1997.
[5]A. M. A. Fateh, A. Eslami, and A. Fahimifar, "A study of the axial load behaviour of helical piles in sand by frustum confining vessel," International Journal of Physical Modelling in Geotechnics, vol. 18, pp. 175-190, 2018.
[6]J. Harnish, "Helical pile installation torque and capacity correlations," Masters of Science Electroninc Thesis and Dissertation Repository. 2855, Civil Engineering, University of Western Ontario, 2015.
[7]J. Khazaei and A. Eslami, "Behavior of Helical Piles – as a Geoenvironmental Choice – – by Frustum Confining Vessel," Advances in Science and Technology Research Journal, vol. 10, pp. 8-22, 2016.
[8]D. Kim, K. Baek, and K. Park, "Analysis of the Bearing Capacity of Helical Pile with Hexagonal Joints," Materials (Basel), vol. 11, Oct 2 2018.
[9]N. P. Kurian and S. J. Shah, "Studies on the behaviour of screw piles by the finite element method," Canadian Geotechnical Journal, vol. 46, pp. 627-638, 2009.
[10]R. S. Merrifield, "Ultimate Uplift Capacity of Multiplate Helical Type Anchors in Clay," Journal of Geotechnical and Geoenvironmental Engineering, vol. 137, pp. 704-716, 2011.
[11]A. Mohammadi, T. Ebadi, and M. R. Boroomand, "Physical Modelling of Axial Compressive Bearing Capacity of Instrumented Piles in Oil-Contaminated Sandy Soil," Iranian Journal of Science and Technology, Transactions of Civil Engineering, vol. 44, pp. 695-714, 2019.
[12]H. Nagai, T. Tsuchiya, and M. Shimada, "Influence of installation method on performance of screwed pile and evaluation of pulling resistance," Soils and Foundations, vol. 58, pp. 355-369, 2018.
[13]M. Zare and A. Eslami, "Study of deep foundation performances by frustum confining vessel (FCV)," International Journal of Civil Engineering, vol. 12, pp. 271-280, 2014.
[14]M. Zarrabi and A. Eslami, "Behavior of Piles under Different Installation Effects by Physical Modeling," International Journal of Geomechanics, vol. 16, 2016.
[15]D. S. Robert G. Horvath, "Frustum confining vessel for testing model piles," Canadian Geotechnical Journal, vol. 33, p. 6, 1996.
[16]A. Eslami, S. Moshfeghi, H. MolaAbasi, and M. M. Eslami, "Geotechnical engineering," in Piezocone and Cone Penetration Test (CPTu and CPT) Applications in Foundation Engineering, ed, 2020, pp. 1-23.
[17]H. Mortazavibak, A. Halabian, H. Hashemalhosseini, M. Roshanzamir, A. Jafari, and B. Shabadagh, "Design Optimisation of the Size and Geometry of Frustum Confining Vessel," in 13TH INTERNATIONAL CONFERENCE ON THE MECHANICAL BEHAVIOUR OF MATERIALS, 2019, p. 298.
[18]A. Jassim;, N. Ganjian;, and A. Eslami, "Design and Fabrication of Frustum Confining Vessel Apparatus for Model Pile Testing in Saturated Soil," Innovative Infrastructure Solutions, 2022.
[19]A. h. Karimi and A. Eslami, "Physical modelling for pile performance combined with ground improvement using frustum confining vessel," International Journal of Physical Modelling in Geotechnics, vol. 18, 2017.
[20]J. Khazaei and A. Eslami, "Geotechnical behavior of helical piles via physical modeling by Frustum Confining Vessel (FCV)," International Journal of Geography and Geology, vol. 5, pp. 167-181, 2016.
[21]A. Karimi, A. Eslami, M. Zarrabi, and J. Khazaei, "Study of pile behavior by improvement of confining soils using frustum confining vessel," Scientia Iranica, vol. 24, pp. 1874-1882, 2017.
[22]M. Zarrabi and A. Eslami, "Behavior of piles under different installation effects by physical modeling," International Journal of Geomechanics, vol. 16, p. 04016014, 2016.
[23]A. M. A. Fateh, A. Eslami, and A. Fahimifar, "Study of soil disturbance effect on bearing capacity of helical pile by experimental modelling in FCV," International Journal of Geotechnical Engineering, vol. 11, pp. 289-301, 2017.
[24]H. A. Perko, Helical Piles: A practical guide to design and installation: John Wiley & Sons, 2009.
[25]A. J. Lutenegger, "Behavior of multi-helix screw anchors in sand," in Proceeding of the 14th Pan-American Conference on Soil Mechanics and Geotechnical  Engineering, Toronto, 2011.
[26]E. Shojaei, A. Eslami, and N. Ganjian, "Self-expanded piles: A new approach to unconventional piles development," Marine Georesources & Geotechnology, vol. 39, 2021.
[27]H. Mortazavibak, A. Halabian, H. Hashemalhosseini, and M. Rowshanzamir, "An investigation on the axial response and material efficiency of tapered helical piles," Journal of Rock Mechanics and Geotechnical Engineering, vol. 13, 2021.
[28]G. Sedran, D. F. Stolle, and R. G. Horvath, "An investigation of scaling and dimensional analysis of axially loaded piles," Canadian geotechnical journal, vol. 38, pp. 530-541, 2001.
[29]C. G. S. F. Committee, Canadian foundation engineering manual: Canadian Geotechnical Society., 2006.
[30]A. D2487, "Standard practice for classification of soils for engineering purposes (unified soil classification system). ASTM International, West Conshohocken, PA, 2017," ed, 2017.
[31]A. D6913, Standard test methods for particle-size distribution (gradation) of soils using sieve analysis: ASTM International, 2009.
[32]A. D7181, Standard Test Method for Consolidated Drained Triaxial Compression Test for Soils: ASTM International, 2020.
[33]A. D1143/D1143M-07, Standard Test Method for Piles Under Static Axial Compressive Load: ASTM International, 2013.