Three-Dimensional Numerical Study of the Tensile Capacity of Helical Multi-Plates Anchors

Document Type : Research Article


1 Department of Civil Engineering, Yazd University, Yazd, Iran.

2 Department of Civil Engineering, Yazd University, Yazd, Iran


Nowadays, helical anchors are one of the fastest methods of supporting excavations. The use of helical anchors is increasing, and recently they received more attention in researches. One of the most important factors for the design of helical anchors is their tensile capacity, to which less attention was paid in the literature compared with the helical piles. The present study uses a three-dimensional numerical modeling approach to investigate the tensile capacity of helical multi-plate anchors. For this purpose, first, the adopted numerical modeling methodology is verified. Then, a comprehensive parametric study is performed to investigate the effects of various parameters involving the soil type, soil cohesion, plate diameter, plate spacing, surcharge, and anchor inclination. The present study results show that the tensile capacities of the helical multi-plate anchors increase by increasing the plate’s diameter, surcharge, and soil relative density. However, the soil cohesion and anchor inclination have negligible effects. Moreover, the results indicate that the load-bearing shares of the shaft increase by increasing the surcharge and decreasing the plate diameter. In addition, the results show that the load-bearing shares of the plates stay about constant for S/D≥4 (S and D represent the plate's Spacing and Diameter, respectively). So that the failure mechanism of multi-plate anchors could be considered as the individual plate for S/D≥4 and cylindrical shear for S/D<4. In other words, the critical S/D ratio is 4. The union of failure zones formed around the plates in displacement contours for S/D<4 confirms this result.


Main Subjects

  1. Nazir, H.S. Chuan, H. Niroumand, K.A. Kassim, Performance of single vertical helical anchor embedded in dry sand, Measurement, 49 (2014) 42-51.
  2. P. Clemence, A.J. lutenegger, Industry survey of state of practice for helical piles and tiebacks, DFI., 9(1) (2015) 12-41.
  3. Beim, S.C. Luna, Results of dynamic and static load tests on helical piles in the varved clay of Massachusetts, DFI, 6(1) (2012) 58-67.
  4. [J.A. Cherry, H.A. Perko, Deflection of helical piles: a load tests database review, in: Proceedings of The 1st International Geotechnical Symposium on Helical Foundations, 2013.
  5. Elkasabgy, Dynamic and static performance of large-capacity Helical piles in cohesive soil, Ph.D. Thesis, The University of Western Ontario, Ontario, Canada, 2011.
  6. Elkasabgy, M.H. El Naggar, Dynamic response of vertically loaded helical and driven steel piles, Can. Geotech. J., 50(5) (2013) 521-535.
  7. -J. Feng, W.-D. Fu, H.-X. Chen, H.-X. Li, Y.-L. Xie, J. Li, Field tests of micro screw anchor piles under different loading conditions at three soil sites, Bull. Eng. Geol. Environ., 80(1) (2021) 127-144.
  8. Ghaly, A. Hanna, M. Hanna, Uplift behavior of screw anchors in sand. I: dry sand, J. Geotech. Eng. -ASCE, 117(5) (1991) 773-793.
  9. Hao, D. Wang, C.D. O'Loughlin, C. Guadin, Tensile monotonic capacity of helical anchors in sand: interaction between helices, Can. Geotech. J., 56(10) (2019) 1534-1543.
  10. A. Malik, J. Kuwano, S. Tachibana, T. Maejima, Effect of helix bending deflection on load settlement behavior of screw pile Acta Geotech., 14(5) (2019) 1527-1543.
  11. Mittal, S. Mukherjee, Behaviour of group of helical screw anchors under compressive loads, Geotech. Geol. Eng., 33(3) (2015) 575-592.
  12. Nagai, T. Tsuchiya, M. Shimada, Influence of installation method on performance of screwed pile and evaluation of pulling resistance, Soils Found., 58(2) (2018) 355-369.
  13. A. Perez, J.A. Sciavon, Numerical and experimental study on influence of installation effects on behavior of helical anchors in very dense sand, Can. Geotech. J., 55(8) (2018) 1067-1080.
  14. Salhi, O. Nait-Rabah, C. Deyrat, C. Roos, Numerical modeling of single helical pile behavior under compressive loading in sand, EJGE, 18 (2013) 4319-4338.
  15. A. Schiavon, C.d.H.C. Tsuha, L. Thorel, Monotonic, cyclic and post-cyclic performances of single-helix anchor in residual soil of sandstone J. Rock Mech. Geotech. Eng., 11(4) (2019) 824-836.
  16. Spagnoli, C. de Hollanda Cavalanti Tusha, A review on the behavior of helical piles as a potential offshore foundation system, Mar. Geores. Geotechnol., 38(9) (2020) 1-24.
  17. Tokhi, G. Ren, J. Li, Laboratory study of a new screw nail and its interaction in sand, Comput. Geotech., 78 (2016) 144-154.
  18. Tokhi, G. Ren, J. Li, Laboratory pullout resistance of a new screw soil nail in residual soil, Can. Geotech. J., 55(5) (2018) 609-619.
  19. Wang, R. Merifield, C. Gaudin, Uplift behavior of helical anchors in clay, Can. Geotech. J., 50(6) (2013) 575-584.
  20. Cerfontaine, J.A. Knappett, M.J. Brown, A. Bradshaw, Effect of soil deformability on the failure mechanism of shallow plate or screw anchors in sand, Comput. Geotech, 109 (2019) 34-45.
  21. A. Garakani, J. Maleki, Load capacity of Helical Piles with different geometrical aspects sandy and clayey soils: A Numerical Study, in: International Congress and Exhibition Sustainable Civil Infrastructures, Springer, Egypt, 2019, pp. 73-84.
  22. Ghosh, S. Samal, Interaction effect of helical anchors in cohesive soil using finite element analysis, Geotech. Geol. Eng., 35(4) (2017) 1475-1490.
  23. Kwon, J. Lee, G. Kim, I. Kim, J. Lee, Investigation of pullout load capacity for helical anchors subjected to inclined loading conditions using coupled Eulerian-Lagrangian analyses, Comput. Geotech, 111 (2019) 66-75.
  24. Merifield, C. Smith, The Ultimate Uplift Capacity of Multi-Plate Anchor in Undrained Clay, in: Soil behaviour and geo-micromechanics, 2010, pp. 74-79.
  25. Pandey, V.B. Chauhan, Numerical analysis for the evaluation of pull-out capacity of helical anchors in sand, in: International Congress and Exhibition Sustainable Civil Infrastructures, 2019, pp. 207-218.
  26. Rawat, A. Gupta, Analysis of a nailed soil slope using limit equilibrium and finite element methods, Int. J. Geosynth. Ground Eng., 2(4) (2016) 1-23.
  27. Rawat, A.K. Gupta, Numerical modeling of pullout of helical soil nail, J. Rock Mech. Geotech. Eng., 9(4) (2017) 648-658.
  28. Sharma, S. Guner, System-level modeling methodology for capturing the pile cap, helical pile group, and soil interaction under uplift loads, Eng. Struct., 220 (2020).
  29. Spagnoli, S. Mendez, M. Carlos, C. de Hollanda Cavalanti Tusha, P. Oreste, Parametric analysis for the estimation of the installation power for large helical piles in dry cohesionless soils, Int. J. Geotech. Eng., 14(5) (2020) 569-579.
  30. Tang, K.-K. Phoon, Model uncertainty of cylindrical shear method for calculating the uplift capacity of helical anchors in clay, Eng. Geol., 207 (2016) 14-23.
  31. Wang, Y. Hu, M. Randolph, Three-dimensional large deformation finite element analysis of plate anchors in uniform clay, J. Geotech. Geoenviron. Eng., 136(2) (2010) 355-365.
  32. M. Bak, A.M. Halabian, H. Hashemolhosseini, M. Rowshanzamir, Axial response and material efficiency of tapered helical piles, J. Rock Mech. Geotech. Eng., 13(1) (2021) 176-187.
  33. Rawat, A. Gupta, A. Kumar, Pullout of soil nail with circular discs: a three-dimensional finite element analysis, J. Rock Mech. Geotech. Eng., 9(5) (2017) 967-980.
  34. U. Sharif, M.J. Brown, B. Cerfontaine, C. Davidson, M.O. Ciantia, J.A. Knappett, J.D. Ball, A. Brennan, C. Augarde, W. Coombs, A. Blake, D. Richards, D. White, M. Huisman, M. Ottolini, Effects of screw pile installation on installation requirements and in-service performance using the discrete element method, Canadian Geotechnical Journal, 58(9) (2021) 1334-1350.
  35. Cerfontaine, M. Ciantia, M.J. Brown, Y.U. Sharif, DEM study of particle scale and penetration rate on the installation mechanisms of screw piles in sand, Computers and Geotechnics, 139 (2021) 17.
  36. Itasca Consulting Group, FLAC3D 6.0 User Manual, 2017.
  37. Chance, Chance Technical Design Manual, 4th ed., Chance Company, USA, 2004.
  38. Abdelrahman, E. Shaarawi, K. Abouzaid, Interpretation of axial pile load test results for continuous flight auger piles, in: Emerging Technologies in Structural Engineering. Proceedings of the 9th Arab Structural Engineering Conference 2003, pp. 796.
  39. Baligh, G. Abdelrahman, Modification of Davisson's method, in: Proceedings of the 16th International Conference on Soil Mechanics and Geotechnical Engineering, 2005, pp. 2079-2082.
  40. D.C. Garcia, Assessment of Helical Anchors Bearing Capacity For Offshore Aquaculture Applications, The University of Maine, 2019.
  41. A. Garakani, A Guideline For Design, Execution And Testing of Energy Piles, NRI, Iran, 2019.
  42. Terzaghi, Theoretical Soil Mechanics, New York, (1943) 11-15.
  43. Merifield, Ultimate uplift capacity of multiplate helical type anchors in clay, J. Geotech. Geoenviron. Eng., 137(7) (2011) 704-716.
  44. J. Lutenegger, Behavior of multi-helix screw anchors in sand, in: Proceedings of the 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, Toronto, Ontario, 2011.
  45. N. Rao, Y. Prasad, M.D. Shetty, The behavior of model screw piles in cohesive soils, Soils Found., 31(2) (1991) 35-50.