Calculation for Frost Jacking Resistance of Single Helical Steel Piles in Cohesive Soils
Publication: Journal of Cold Regions Engineering
Volume 35, Issue 2
Abstract
Helical steel piles (HSPs) are currently used as supports for photovoltaic panels in seasonally frozen ground in order to mitigate the adverse impacts of frost jacking; nevertheless, issues frequently arise due to considerable frost-heave forces through the frozen domain and the piles' limited embedment depth. This study aims to properly estimate the heaving of HSPs and the mobilized resisting forces as the frost penetrates, providing a quick guide to the application. To this end, small-scale model tests were first performed on three types of HSPs installed in cohesive soil with a straight-shaft pile served as a comparison. The pile head was vertically constrained or unconstrained when the surrounding soil was to be frozen from the top down. A linear relationship between the anchor-resisting force and pile head displacement was then derived from test data, and its implications for other boundary conditions (e.g., dead load and flexible boundary at pile head) were discussed. A calculation method was finally proposed to analyze the thermomechanical behavior of HSPs during unidirectional freezing process. The applicability of this approach was examined by two indicators. Hopefully, the findings of this paper can be synthesized into design criterion and facilitate a wider use of HSPs.
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Acknowledgments
This work was supported by the National Natural Science Foundation of China (Grant Nos. 41901073, 41731281, and 51878560), the China Postdoctoral Science Foundation (Grant No. 2019M663556), and the Fundamental Research Funds for the Central Universities (Grant No. 2682020CX66).
Notation
The following symbols are used in this paper:
- Ah
- projected area of a helix;
- D
- helix diameter;
- d
- shaft diameter;
- Fa
- anchor-resisting force;
- Fb
- constraints at the pile head;
- Fj
- tangential frost-heave force;
- G
- shear modulus;
- Heff
- effective embedded length of pile shaft above the top helix according to shadow effect;
- Hf
- depth of frost penetration;
- Ht
- embedment depth of top helix;
- hi
- depth;
- k
- constant term relate to a line slope;
- Lc
- distance between top and bottom helices;
- Nu
- uplift bearing capacity factor for cohesive soils;
- P
- helix pitch;
- rH
- affected radial distance within soil;
- S
- helix spacing;
- sci
- critical value for the onset of the rupture of ice bond;
- scs
- critical value for the formation of shear failure surface;
- Sf
- spacing ratio factor;
- sH
- heave at pile head;
- si
- shear displacement on the pile–soil interface;
- ss
- local shear displacement of soils adjacent to the helices;
- Su
- undrained shear strength of soils;
- Tf
- freezing point;
- Ti
- real-time temperature;
- t
- thickness of helical plate;
- α0
- adhesion factor at shaft–soil interface;
- γ′
- effective unit weight of soil;
- γH
- shear strain close to helix;
- φh
- inclined angle for the cross section of helical plate;
- τa
- adfreeze bond strength;
- τH
- shear stress for soil close to helix; and
- ηf
- freezing factor.
References
Adams, J. I., and T. W. Klym. 1972. “A study of anchorages for transmission tower foundations.” Can. Geotech. J. 9 (1): 89–104. https://doi.org/10.1139/t72-007.
Andersland, O. B., and B. Ladanyi. 1994. “Foundations in frozen soils.” In An introduction to frozen ground engineering, edited by O. B. Andersland, and B. Ladanyi, 182–224. Boston, MA: Springer.
Crowther, G. 2015. “Lateral pile analysis frozen soil strength criteria.” J. Cold Reg. Eng. 29 (2): 04014011. https://doi.org/10.1061/(ASCE)CR.1943-5495.0000078.
Hawkins, K., and R. Thorsten. 2009. “Load test results—Large diameter helical pipe piles.” In Contemporary Topics in Deep Foundations, Geotechnical Special Publication 185, edited by M. Iskander, D. F. Laefer, and M. H. Hussein, 488–495. Reston, VA: ASCE.
Hoyt, R. M., and S. P. Clemence. 1989. “Uplift capacity of helical anchors in soil.” In Proc., 12th Int. Conf. on Soil Mechanics and Foundation Engineering, 1019–1022. Oxfordshire, UK: Taylor & Francis.
Johnston, G. H., and B. Ladanyi. 1974. “Field tests of deep power-installed screw anchors in permafrost.” Can. Geotech. J. 11 (3): 348–358. https://doi.org/10.1139/t74-036.
Liu, H., H. K. Zubeck, and D. H. Schubert. 2007. “Finite-element analysis of helical piers in frozen ground.” J. Cold Reg. Eng. 21 (3): 92–106. https://doi.org/10.1061/(ASCE)0887-381X(2007)21:3(92).
Liu, J., T. Wang, B. Tai, and P. Lv. 2020. “A method for frost jacking prediction of single pile in permafrost.” Acta Geotech. 15 (2): 455–470. https://doi.org/10.1007/s11440-018-0711-0.
Liu, J. K., T. F. Wang, and Z. Wen. 2018. “Research on pile performance and state-of-the-art practice in cold regions.” Sci. Cold Arid Reg. 10 (1): 1–11. https://doi.org/10.3724/SP.J.1226.2018.00001.
Livneh, B., and M. H. El Naggar. 2008. “Axial testing and numerical modelling of square shaft helical piles under compressive and tensile loading.” Can. Geotech. J. 45 (8): 1142–1155. https://doi.org/10.1139/T08-044.
Mitsch, M. P., and S. P. Clemence. 1985. “The uplift capacity of helix anchors in sand.” In Uplift Behaviour of Anchor Foundations in Soil, 26–47. Reston, VA: ASCE.
Mohajerani, A., D. Bosnjak, and D. Bromwich. 2016. “Analysis and design methods of screw piles: A review.” Soils Found. 56 (1): 115–128. https://doi.org/10.1016/j.sandf.2016.01.009.
Mooney, J. S., S. Adamczak, and S. P. Clemence. 1985. “Uplift capacity of helical anchors in clay and silt.” In Uplift Behavior of Anchor Foundations in Soil, 48–72. Reston, VA: ASCE.
Nasr, M. 2004. “Large capacity screw piles.” In Int. Conf.: Future Vision and Challenges for Urban Development, 1–15. Cairo, Egypt: Np.
Rao, S. N., Y. V. S. N. Prasad, and C. Veeresh. 1993. “Behaviour of embedded model screw anchors in soft clays.” Géotechnique 43 (4): 605–614. https://doi.org/10.1680/geot.1993.43.4.605.
Sakr, M. 2009. “Performance of helical piles in oil sand.” Can. Geotech. J. 46 (9): 1046–1061. https://doi.org/10.1139/T09-044.
Sakr, M. 2011. “Installation and performance characteristics of high capacity helical piles in cohesionless soils.” Deep Found. J. 5 (1): 39–57.
Sego, D. C., K. W. Biggar, and G. Wong. 2003. “Enlarged base (belled) piles for use in ice or ice-rich permafrost.” J. Cold Reg. Eng. 17 (2): 68–88. https://doi.org/10.1061/(ASCE)0887-381X(2003)17:2(68).
Tappenden, K., and D. Sego. 2007. “Predicting the axial capacity of screw piles installed in Canadian soils.” In Proc., 60th Canadian Geotechnical Society Conf., 1608–1615. Ottawa, ON: Canadian Geotechnical Society.
Tappenden, K., D. Sego, and P. Robertson. 2009. “Load transfer behaviour of full-scale instrumented screw anchors.” In Contemporary Topics in Deep Foundations, Geotechnical Special Publication 185, edited by M. Iskander, D. F. Laefer, and M. H. Hussein, 472–479. Reston, VA: ASCE.
Tsuha, C. H., and N. Aoki. 2010. “Relationship between installation torque and uplift capacity of deep helical piles in sand.” Can. Geotech. J. 47 (6): 635–647. https://doi.org/10.1139/T09-128.
Wang, T., J. Liu, Y. Tian, and P. Lv. 2017. “Frost jacking characteristics of screw piles by model testing.” Cold Reg. Sci. Technol. 138: 98–107. https://doi.org/10.1016/j.coldregions.2017.03.008.
Yang, Z. J., X. R. Zhang, Y. Yang, X. Zhou, and F. Niu. 2018. “Shake table modeling of pile foundation performance in laterally spreading frozen ground crust overlying liquefiable soils.” J. Cold Reg. Eng. 32 (4): 04018012. https://doi.org/10.1061/(ASCE)CR.1943-5495.0000171.
Zhang, D. J. Y., R. Chalaturnyk, P. K. Robertson, D. C. Sego, and G. Cyre. 1998. “Screw anchor test program (Part I): Instrumentation, site characterisation and installation.” In Proc., 51st Canadian Geotechnical Conf, 1–8. Edmonton, AB: Canadian Geotechnical Society.
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Published In
Journal of Cold Regions Engineering
Volume 35 • Issue 2 • June 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Sep 26, 2019
Accepted: Oct 23, 2020
Published online: Jan 20, 2021
Published in print: Jun 1, 2021
Discussion open until: Jun 20, 2021
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