Effect of Helix Position on the Lateral Resistance of Battered Single-Helix Piles Located on a Sandy Slope Crest
Publication: International Journal of Geomechanics
Volume 24, Issue 3
Abstract
Helical piles are commonly used as foundations under electrical transmission towers, bridge abutments, highway signs, and light poles. The present experimental investigation focused on the lateral resistance of vertical and battered single-helix piles installed on the crest of Slopes 1V:2H and 1V:3H. The helix was placed at various positions below the ground surface, such as 0.25 Lp, 0.35 Lp, and 0.45 Lp (“Lp” refers to the embedment length of the pile), to analyze the influence of helix position on the lateral capacity of single-helix piles. The negative batter angle was varied as 7.5°, 15°, and 22.5° for all single-helix piles with different helix positions. The lateral capacity of the battered helical pile was compared with that of the vertical helical pile and the vertical regular pile (without helix) to assess the batter efficiency and net efficiency, respectively. A linear regression model was proposed to depict the variation of batter efficiency with several significant response variables like slope angle (α), batter angle (β), pitch (p), helix diameter (Dh), and shaft diameter (Dp). It was found that the battered single-helix pile with a helix at an embedment depth of 0.35 Lp is beneficial in improving the allowable lateral capacity for batter angles up to 15° on Slope 1V:2H. The helix position closer to the ground level (h = 0.25 Lp) was relatively efficient on Slope 1V:3H because higher lateral resistance mobilization occurs at a relatively shallow depth on the gentle slope. The allowable lateral capacity of the single-helix pile battered at 22.5° showed a remarkable improvement by 50%–53% on Slope 1V:2H and 22%–32% on Slope 1V:3H. The effect of helix was significant at smaller batter angles of 7.5° and 15° but turned marginalized at a higher batter angle of 22.5°.
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Data Availability Statement
No data, models, or codes were generated or used during the study.
Acknowledgments
The authors express gratitude toward the Science and Engineering Research Board (SERB) [Sanction order no. (File No. EEQ/2021/000045)], DST, Government of India, for providing financial assistance to the project titled “Experimental investigation on conventional and innovative piles for offshore wind turbines (OWT) foundation system subjected to long-term cyclic loading.”
Notations
The following symbols are used in this paper:
- A
- coefficient denoting the ratio of modulus of elasticity to effective overburden pressure;
- C
- strain calibration constant relating strain to moment;
- Cc
- coefficient of curvature;
- Cu
- coefficient of uniformity;
- Dh
- outer diameter of the helix;
- Dp
- outer diameter of the pile shaft;
- Dr
- relative density of sand;
- D10
- effective grain size;
- E50
- secant stiffness of sand obtained from the triaxial test;
- representative secant stiffness of sand;
- EpIp
- flexural rigidity of the pile;
- Hvh
- horizontal distance of the helix moved from the vertical pile position;
- Hvh
- horizontal distance of the helix from the extreme edge of the slope face;
- h
- helix embedment depth measured from ground level;
- Ko
- coefficient of earth pressure at rest;
- Lt
- total length of the pile;
- Lp
- embedded length of the pile;
- Lc
- critical length of the soil–pile system;
- M
- bending moment along the pile shaft;
- Mm
- bending moment at node “m”;
- P
- lateral load applied near the ground level;
- p
- pitch of the helix;
- Sv
- vertical helix distance measured between the top and bottommost point of the helix;
- Vm
- shear force at node “m” along the pile shaft;
- y
- lateral deflection near the ground level;
- z
- depth measured from ground level;
- (ps)m
- soil resistance per unit length at node “m” along the pile shaft;
- α
- slope angle measured with respect to the horizontal level;
- β
- negative batter angle measured with reference to vertical;
- γ
- unit weight of soil;
- γmax
- maximum unit weight in the densest state;
- γmin
- minimum unit weight in the loosest state;
- σ0.5f
- axial compressive stress corresponds to 50% of the failure stress;
- mean effective confining stress;
- ηh
- coefficient determining the rate of increment of stiffness with depth;
- ηvH
- helix efficiency of the vertical single-helix pile;
- ηbH
- batter efficiency of the battered single-helix pile;
- ηbR
- batter efficiency of the battered regular pile;
- ηnet
- net fin efficiency of the battered single-helix pile;
- ξ
- bending strain; and
- ϕ
- angle of shearing resistance.
References
ABC (AB Chance). 2010. Guide to model specification CHANCE® civil construction: Helical piles for structural support. Bulletin 01-0303. Shelton, CT: Hubbell.
Abdelhalim, R. A., M. El Sawwaf, A. M. Nasr, and A. Farouk. 2020. “Experimental and numerical studies of laterally loaded piles located near oil-contaminated sand slope.” Eng. Sci. Technol. Int. J. 23 (4): 744–757. https://doi.org/10.1016/j.jestch.2020.03.001.
Abdrabbo, F. M., and A. Z. El Wakil. 2016. “Laterally loaded helical piles in sand.” Alexandria Eng. J. 55 (4): 3239–3245. https://doi.org/10.1016/j.aej.2016.08.020.
Al-Baghdadi, T. A., M. J. Brown, J. A. Knappett, and A. H. Al-Defae. 2017. “Effects of vertical loading on lateral screw pile performance.” Proc. Inst. Civ. Eng. Geotech. Eng.170 (3): 259–272. https://doi.org/10.1680/jgeen.16.00114.
Al Heib, M., F. Emeriault, and H. L. Nghiem. 2020. “On the use of 1g physical models for ground movements and soil-structure interaction problems.” J. Rock Mech. Geotech. Eng. 12 (1): 197–211. https://doi.org/10.1016/j.jrmge.2019.07.006doi:10.1016/j.jrmge.2019.07.006.
Ali Zomorodian, S. M., and M. Dehghan. 2011. “Lateral resistance of a pile installed near a reinforced slope.” Int. J. Phys. Modell. Geotech. 11 (4): 156–165. https://doi.org/10.1680/ijpmg.2011.11.4.156.
Arshad, M., and B. C. O’Kelly. 2017. “Model studies on monopile behavior under long-term repeated lateral loading.” Int. J. Geomech. 17 (1): 04016040. https://doi.org/10.1061/(asce)gm.1943-5622.0000679.
Ashour, M., A. Alaaeldin, and M. G. Arab. 2020. “Laterally loaded battered piles in sandy soils.” J. Geotech. Geoenviron. Eng. 146 (1): 06019017. https://doi.org/10.1061/(asce)gt.1943-5606.0002186.
Beena, K. S., P. E. Kavitha, and K. P. Narayanan. 2017. “Model Studies on Laterally Loaded Piles in Sloping Clay Bed.” Indian Geotech. J. 48 (1): 114–124. https://doi.org/10.1007/s40098-017-0248-4.
Bhattacharya, S., D. Lombardi, and D. Muir Wood. 2011. “Similitude relationships for physical modelling of monopile-supported offshore wind turbines.” Int. J. Phys. Modell. Geotech. 11 (2): 58–68. https://doi.org/10.1680/ijpmg.2011.11.2.58.
Bolton, M. D. 1986. “The strength and dilatancy of sands.” Géotechnique 36 (1): 65–78. https://doi.org/10.1680/geot.1986.36.1.65.
Bradka, T. D. 1997. Vertical capacity of helical screw anchor piles. Master of Engineering Rep. Alberta, AB, Canada: Univ. of Alberta.
Byrne, B. W., and G. T. Houlsby. 2015. “Helical piles: An innovative foundation design option for offshore wind turbines.” Phil. Trans. R. Soc. A373: 20140081. https://doi.org/10.1098/rsta.2014.0081.
Chae, K. S., K. Ugai, and A. Wakai. 2004. “Lateral resistance of short single piles and pile groups located near slopes.” Int. J. Geomech. 4 (2): 93–103. https://doi.org/10.1061/(asce)1532-3641(2004)4:2(93).
Chakraborty, T., and R. Salgado. 2010. “Dilatancy and shear strength of sand at low confining pressures.” J. Geotech. Geoenviron. Eng. 136 (3): 527–532. https://doi.org/10.1061/(asce)gt.1943-5606.0000237.
Cuéllar, P., S. Georgi, M. Baeßler, and W. Rücker. 2012. “On the quasi-static granular convective flow and sand densification around pile foundations under cyclic lateral loading.” Granular Matter 14 (1): 11–25. https://doi.org/10.1007/s10035-011-0305-0.
Deendayal, R., K. Muthukkumaran, and T. G. Sitharam. 2020. “Analysis of laterally loaded group of piles located on sloping ground.” Int. J. Geotech. Eng. 14 (5): 580–588. https://doi.org/10.1080/19386362.2018.1448521.
Deendayal, R., K. Muthukkumaran, and T. G. Sitharam. 2016a. “Response of laterally loaded pile in soft clay on sloping ground.” Int. J. Geotech. Eng. 10 (1): 10–22. https://doi.org/10.1179/1939787915y.0000000013.
Deendayal, R., T. G. Sitharam, and K. Muthukkumaran. 2016b. “Effect of earthquake on a single pile located in sloping ground.” Int. J. Geotech. Earthquake Eng. 7 (1): 57–72. https://doi.org/10.4018/IJGEE.2016010104.
Elkasabgy, M., and M. H. El Naggar. 2014. “Axial compressive response of large-capacity helical and driven steel piles in cohesive soil.” Can. Geotech. J. 52 (2): 224–243. https://doi.org/10.1139/cgj-2012-0331.
Fahmy, A., and M. H. El Naggar. 2017. “Axial and lateral performance of spun-cast ductile iron helical tapered piles in clay.” Proc. Inst. Civ. Eng. Geotech. Eng. 170 (6): 503–516. https://doi.org/10.1680/jgeen.16.00116.
Fateh, A. M. A., A. Eslami, and A. Fahimifar. 2016. “Direct CPT and CPTu methods for determining bearing capacity of helical piles.” Mar. Georesour. Geotechnol. 35 (2): 193–207. https://doi.org/10.1080/1064119x.2015.1133741.
Franke, E., and G. Muth. 1985. “Scale effect in 1-g model tests on horizontally loaded piles.” In Vol. 2 of Proc., 11th Int. Conf. on Soil Mechanics and Foundation Engineering. 1011–1014. Rotterdam, Netherlands: A. A. Balkema.
FSI. 2014. Technical manual: Helical piles and anchors, hydraulically driven push piers, polyurethane injection and supplemental support systems, 2nd ed., 33–39. Omaha: Foundation Support Works.
Georgiadis, K., and M. Georgiadis. 2010. “Undrained lateral pile response in sloping ground.” J. Geotech. Geoenviron. Eng. 136 (11): 1489–1500. https://doi.org/10.1061/(asce)gt.1943-5606.0000373.
Georgiadis, K., M. Georgiadis, and C. Anagnostopoulos. 2013. “Lateral bearing capacity of rigid piles near clay slopes.” Soils Found. 53 (1): 144–154. https://doi.org/10.1016/j.sandf.2012.12.010.
Hazzar, L., M. N. Hussien, and M. Karray. 2017. “Numerical investigation of the lateral response of battered pile foundations.” Int. J. Geotech. Eng. 11 (4): 376–392. https://doi.org/10.1080/19386362.2016.1224030.
Huang, Y., H. L. Cheng, T. Osada, A. Hosoya, and F. Zhang. 2015. “Mechanical behavior of clean sand at low confining pressure: Verification with element and model tests.” J. Geotech. Geoenviron. Eng. 141 (8): 06015005. https://doi.org/10.1061/(asce)gt.1943-5606.0001330.
ICC (International Code Council). 2006. International building code (IBC). Washington, DC: International Code Council.
ICC-ES (ICC-Evaluation Services). 2012. “AC358 Acceptance criteria for helical pile systems and devices.” Accessed February 5, 2022. www.icc-es.org.
Juvekar, M. S., and P. J. Pise. 2008. “Behavior of rigid batter piles and pile groups subjected to horizontal load in sand.” Indian Geotech. J. 38 (2): 221–242.
Kallioglou, T., A. Papadopoulou, and K. Pitilakis. 2003. “Shear modulus and damping of natural sands.” In Deformation characteristics of geomaterials, 401–407. Rotterdam, Netherlands: A. A. Balkema.
Mezazigh, S., and D. Levacher. 1998. “Laterally loaded piles in sand: Slope effect on P–Y reaction curves.” Can Geotech J. 35 (3): 433–441. https://doi.org/10.1139/t98-016.
Mittal, S., B. Ganjoo, and S. Shekhar. 2010. “Static Equilibrium of Screw Anchor Pile Under Lateral Load in Sands.” Geotech. Geol. Eng. 28 (5): 717–725. https://doi.org/10.1007/s10706-010-9342-4.
Muthukkumaran, K. 2014. “Effect of slope and loading direction on laterally loaded piles in cohesionless soil.” Int. J. Geomech. 14 (1): 1–7. https://doi.org/10.1061/(asce)gm.1943-5622.0000293.
Ng, C. W. W., L. M. Zhang, and K. K. S. Ho. 2001. “Influence of laterally loaded sleeved piles and pile groups on slope stability.” Can. Geotech. J. 38 (3): 553–566. https://doi.org/10.1139/t00-109.
Nunez, I. L., R. Philips, M. F. Randolph, and B. D. Wesselink. 1988. “Modelling laterally loaded piles in calcareous sand.” In Proc. of Int. Conf. Centrifuge 88, 353–362. London: Taylor and Francis.
Oztoprak, S., and M. D. Bolton. 2013. “Stiffness of sands through a laboratory test database.” Géotechnique 63 (1): 54–70. https://doi.org/10.1680/geot.10.p.078.
Perko, H. A. 2009. Helical piles: A practical guide to design and installation. Hoboken, NJ: John Wiley & Sons.
Poulos, H., and T. Hull. 1989. “The role of analytical geomechanics in foundation engineering.” In Proc., Foundation Engineering: Current Principles and Practices, 1578–1606. Reston, VA: ASCE.
Prakash, S. 1962. “Behavior of pile groups subjected to lateral loads.” Ph.D. thesis. Dept. of Civil Engineering, Univ. of Illinois.
Prasad, Y. V. S. N., and S. N. Rao. 1996. “Lateral capacity of helical piles in clays.” J. Geotech. Eng. 122 (11): 938–941. https://doi.org/10.1061/(asce)0733-9410(1996)122:11(938).
Puri, V. K., R. W. Stephenson, E. Dziedzic, and L. Gocn. 1984. “Helical anchor piles under lateral loading,” In Laterally loaded deep foundations: Analysis and performance. ASTM STP 835. Edited by J. A. Langer, E. T. Moslcy, and C. D. Thompson, 194–213. West Conshohocken, PA: ASTM.
Raja, N., and K. Muthukkumaran. 2021. “Effect of rock-socketing on laterally loaded piles installed in the proximity of sloping ground.” Int. J. Geomech. 21 (2): 04020252. https://doi.org/10.1061/(asce)gm.1943-5622.0001895.
Rathod, D., K. Muthukkumaran, and T. G. Sitharam. 2017. “Development of non-dimension p–y curves for laterally loaded piles in sloping ground.” Indian Geotech. J. 47 (1): 47–56. https://doi.org/10.1007/s40098-016-0213-7.
Rathod, D., K. Muthukkumaran, and T. G. Sitharam. 2018. “Effect of slope on p–y curves for laterally loaded piles in soft clay.” Geotech. Geol. Eng. 36 (3): 1509–1524. https://doi.org/10.1007/s10706-017-0405-7.
Rathod, D., K. Muthukkumaran, and T. G. Sitharam. 2019. “Experimental investigation on behavior of a laterally loaded single pile located on sloping ground.” Int. J. Geomech. 19 (5): 04019021. https://doi.org/10.1061/(asce)gm.1943-5622.0001381.
Rathod, D., K. T. Krishnanunni, and D. Nigitha. 2020. “A review on conventional and innovative pile system for offshore wind turbines.” Geotech. Geol. Eng. 38 (4): 3385–3402. https://doi.org/10.1007/s10706-020-01254-0.
Reese, L. C., and W. F. Van Impe. 2011. Single piles and pile groups under lateral loading. 2nd ed. Boca Raton, FL: CRC Press.
Remaud, D. 1999. “Pieux sous charges latérales: Étude de l'effet de groupe.” Ph.D. thesis. [In French.] Laboratoire Central des Ponts et Chaussées, Univ. de Nantes.
Sharma, M., D. Choudhury, M. Samanta, S. Sarkar, and V. R. Annapareddy. 2019. “Analysis of helical soil nailed walls under static and seismic conditions.” Can. Geotech. J. 57 (6): 815–827. https://doi.org/10.1139/cgj-2019-0240.
Sharma, M., M. Samanta, and S. Sarkar. 2017. “Laboratory study on pullout capacity of helical soil nail in cohesionless soil.” Can. Geotech J. 54 (10): 1482–1495. https://doi.org/10.1139/cgj-2016-0243.
Spagnoli, G., and C. de Hollanda Cavalcanti Tsuha. 2020. “A review on the behavior of helical piles as a potential offshore foundation system.” Mar. Georesour. Geotechnol. 38 (9): 1013–1036. https://doi.org/10.1080/1064119x.2020.1729905.
Spagnoli, G., C. de Hollanda Cavalcanti Tsuha, P. Oreste, and C. Mauricio Mendez Solarte. 2018. “Estimation of uplift capacity and installation power of helical piles in sand for offshore structures.” J. Waterw. Port Coastal Ocean Eng. 144 (6): 04018019. https://doi.org/10.1061/(asce)ww.1943-5460.0000471.
Taylor, R. N. 1995. Geotechnical centrifuge technology. London: Blackie Academic & Professional.
Terzaghi, K. 1955. “Evalution of coefficients of subgrade reaction.” Géotechnique 5 (4): 297–326. https://doi.org/10.1680/geot.1955.5.4.297.
Tsuha, C. H. C., N. Aoki, G. Rault, L. Thorel, and J. Garnier. 2012. “Evaluation of the efficiencies of helical anchor plates in sand by centrifuge model tests.” Can. Geotech. J. 49 (9): 1102–1114. https://doi.org/10.1139/t2012-064.
Vangla, P., and G. M. Latha. 2015. “Influence of particle size on the friction and interfacial shear strength of sands of similar morphology.” Int. J. Geosynth. Ground Eng. 1 (1): 6. https://doi.org/10.1007/s40891-014-0008-9.
Wood, D. M., A. Crewe, and C. Taylor. 2002. “Shaking table testing of geotechnical models.” Int. J. Phys. Modell. Geotech. 2 (1): 1–13. https://doi.org/10.1680/ijpmg.2002.02.
Yuan, B., R. Chen, G. Deng, T. Peng, Q. Luo, and X. Yang. 2017. “Accuracy of interpretation methods for deriving p–y curves from model pile tests in layered soils.” J. Test. Eval. 45 (4): 20150484. https://doi.org/10.1520/JTE20150484.
Zhang, L., M. C. McVay, and P. W. Lai. 1999. “Centrifuge modelling of laterally loaded single battered piles in sands.” Can. Geotech. J. 36 (6): 1074–1084. https://doi.org/10.1139/t99-072.
Zhu, B., T. Li, G. Xiong, and J. C. Liu. 2016. “Centrifuge model tests on laterally loaded piles in sand.” Int. J. Phys. Modell. Geotech. 16 (4): 160–172. https://doi.org/10.1680/jphmg.15.00023.
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International Journal of Geomechanics
Volume 24 • Issue 3 • March 2024
Copyright
© 2023 American Society of Civil Engineers.
History
Received: Mar 8, 2022
Accepted: Sep 10, 2023
Published online: Dec 29, 2023
Published in print: Mar 1, 2024
Discussion open until: May 29, 2024
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