Laboratory Investigation of the Behavior of Helical Piles under Monotonic Loading at Different Loading Speeds

Document Type : Research Note

Authors

1 Faculty of Civil Engineering of Shahrood University, Shahrood, Iran.

2 Faculty of Civil Engineering of Shahid Beheshti University, Tehran, Iran.

Abstract

Today, one of the primary challenges faced by geotechnical engineers in dealing with problematic soils is to choose a suitable improvement method that, in addition to strengthening the soil, does not cause harmful damage to the environment. Helical piles are a new method that has become very popular in recent years due to the unique features of this type of pile, the most important of which is that it is environmentally friendly. Due to their unique shape and section (having one or more helices along the shaft of the pile), Helical piles have a higher load capacity than usual concrete piles. Among the advantages of using this type of pile, it can be a short installation time with minimal noise and vibration (no need to vibrate for installation), is Easy to implement due to limited access, lightweight, reduction of disturbance soil during installation, and poses less environmental risks and is compatible with nature. According to past studies, it has been found that the current knowledge of the performance of this type of pile and the methods of predicting and determining the bearing capacity currently need to be improved, and this shows the necessity of researching the behavior of these piles. This research, to predict the tensile behavior of Helical piles under different loading speeds and also to investigate the addition of a second helix to a single-helix Helical pile, using the 1g physical modeling device, in two cases of high (95%) and low (45%) relative densities, has been studied. The results obtained in this study show that the effect of relative soil compaction on improving the bearing capacity of the soil was more significant than the loading speed and the number of helices. According to the results of the monotonic tests, the final bearing capacity decreased by about 56% with increasing loading speed; on the other hand, by increasing the relative density and increasing the number of helices, the final load capacity increased, respectively by about 468% and 54%.

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References

1. Spagnoli, G. and de Hollanda Cavalcanti Tsuha, C. 2020.A review on the behavior of helical piles as a potential offshore foundation system. Marine Georesources and Geotechnology, 38(9), pp. 1013–1036. https://doi.org/10.1080/1064119X.2020.1729905.
2. Perko, H.A. 2009. Helical piles: a practical guide to design and installation. John Wiley & Sons.
3. Pack, J.S. 2009. Practical design and inspection guide for helical piles and helical tension anchors. IMR, Inc., Denver, Colorado, Revision, 2.
4. Kurian, N.P. and Shah, S.J. 2009 .Studies on the behaviour of screw piles by the finite element method. Canadian Geotechnical Journal, 46(6), pp. 627–638. https://doi.org/10.1139/T09-008.
5. Silva, B.C. 2014 .Estimation of uplift capacity of helical anchors based on SPT test. M. Sc. Thesis, Department of Geotechnical Engineering, University of São.
6. Tsuha, C. de H.C. 2013 .Influence of multiple helix configuration on the uplift capacity of helical anchors.Congrès International de Mécanique des Sols et de Géotechnique, 18.
7. Perez, Z.A. 2018 .Numerical and experimental study on influence of installation effects on behaviour of helical anchors in very dense sand. Canadian Geotechnical Journal, 55(8), pp. 1067–1080. https://doi.org/10.1139/cgj-2017-0137.
8. Sharma, M., Samanta, M. and Sarkar, S. .Laboratory study on pullout capacity of helical soil nail in cohesionless soil. Canadian Geotechnical Journal, 54(10), pp. 1482–1495. https://doi.org/10.1139/cgj-2016-0243.
9. Liu, H., Zubeck, H.K. and Schubert, D.H. .Finite-element analysis of helical piers in frozen ground. Journal of Cold Regions Engineering, 21(3), pp. 92–106. https://doi.org/10.1061/(ASCE)0887-381X(2007)21:3(92).
10. Spagnoli, G. and Gavin, K. 2015 .Helical piles as a novel foundation system for offshore piled facilities. in Abu Dhabi International Petroleum Exhibition and Conference. OnePetro. https://doi.org/10.2118/177604-MS.
11. Al-Baghdadi, T.A. 2015.Modelling of laterally loaded screw piles with large helical plates in sand. in Frontiers in offshore geotechnics III: proceedings of the 3rd international symposium on frontiers in offshore geotechnics (ISFOG 2015). Taylor & Francis Books Ltd, pp. 503–508.
12.Fateh, A.M.A., Eslami, A. and Fahimifar, A. 2017. Direct CPT and CPTu methods for determining bearing capacity of helical piles. Marine georesources & geotechnology, 35(2), pp. 193–207. https://doi.org/10.1080/1064119X.2015.1133741.
13.Spagnoli, G. 2018 .A sensitivity analysis on the parameters affecting large diameter helical pile installation torque.depth and installation power for offshore applications’, DFI Journal-The Journal of the Deep Foundations Institute, 12(3), pp. 171–185. https://doi.org/10.1080/19375247.2019.1595996.
14.Khazaei, J. and Eslami, A. 2016 .Geotechnical Behavior of Helical Piles Via Physical Modeling by Frustum Confining Vessel (FCV). International Journal of Geography and Geology, 5(9), pp. 167–181. https://doi.org/10.18488/journal.10/2016.5.9/10.9.167.181.
15. Di Bernardo, G. 2012 .Helical pile Deck foundation. New Jersey Deck Boulder, USA .
16.Merifield, R.S. 2011 .Ultimate uplift capacity of multiplate helical type anchors in clay. Journal of Geotechnical and Geoenvironmental Engineering, 137(7), pp. 704–716. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000478.
17. Zare, M. 2013 .Frustum confining vessel (FCV) for investigation of deep foundations performance. in Proc., 38th Annual Int. Conf. on Deep Foundation, Deep Foundation Institute, Phoenix, AZ, pp. 545–553.
18.Ali, A.S., Salim, N.M. and Baqir, H.H. 2022 .The Performance of Taper Helical Pile Embedded in Loose Sand Under Uplift Static and Cyclic Load Using 3D-Finite Element Analysis. in IOP Conference Series: Earth and Environmental Science. IOP Publishing, p. 12033. https://doi.org/10.1088/1755-1315/961/1/012033.
19. Abbas, H.O. and Ali, O.K. 2020 .Parameters affecting screw pile capacity embedded in soft clay overlaying dense sandy soil. in IOP Conference Series: Materials Science and Engineering. IOP Publishing, p. 12117. https://doi.org/10.1088/1757-899X/745/1/012117.
20.Jamill, A.S. and Abbas, H.O. 2021.Effect of Screw Piles Spacing on Group Compressive Capacity in Soft Clay. IOP Conference Series: Materials Science and Engineering, 1076(1), p. 012098. https://doi.org/10.1088/1757-899x/1076/1/012098.
21.Hoseinpour, R., Keramati, M. and de Hollanda Cavalcanti Tsuha, C. 2023 .Effect of the Addition of a Second Helix on the Helical Pile Performance in Sand. International Journal of Civil Engineering, pp. 1–14. https://doi.org/10.1007/s40999-023-00893-7.
 

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