Analysis of Under-Reamed Piles Subjected to Different Types of Load in Clayey Soil

Document Type : Original Article


Engineering Faculty, University of Kufa, Najaf, Iraq


Underreamed piles with one or more bulbs have been widely used in almost all types of soil to support a range of structures. In some cases, in addition to vertical compressive or uplift loads, piles must withstand a considerable lateral load. A 3-D finite element study using ABAQUS software was conducted to examine the behavior of underreamed piles in clay soil under pure lateral, pure uplift, and combined uplift and lateral loads. In this study, pile (L/D) ratios of 11.66, 15, 20, and 25 were considered by adjusting the pile length to simulate the behavior of rigid and flexible piles. The piles were modeled as a linear elastic material, and the soil behavior was simulated using the Drucker-Prager constitutive model. The findings show that the lateral resistance of piles with (L/D) ratios of 11.66 and 15 increased slightly when underreamed piles were used. However, no change in lateral resistance was observed for underreamed piles with (L/D) ratios of 20 and 25 compared with straight piles. The uplift capacity of underreamed piles was significantly greater than that of a straight pile. The lateral capacity was marginally influenced by the prior uplift loading, such that it decreased for a rigid underreamed pile, and increased for a flexible underreamed pile.


  1. I. 2911 P. III, “Indian Standard Code of Practice for Design and Construction of Pile Foundations, Under-reamed Piles.” Bureau of Indian Standard, 1980.
  2. Sharma, D., Jain, M. P., and Prakash, C., Handbook on under-reamed and bored compaction pile foundations. Jain, 1978.
  3. Shrivatsava, S. P., Garg, K. G., and Sonega, M. R. “Under-reamed pile group subjected to lateral loads,” Proc. 3rd Symposium on Application of Soil Mechanics and Foundation Engineering in Eastern India, feb., Calcutta,1972.
  4. Hrennikoff, A., “Analysis of pile foundations with Batter Piles”, Transactions of the American Society of Civil Engineers, Vol. 115, No. 1, 351-374, (1950),
  5. M. R. Soneja and K. G. Garg, “Under-ream piles under lateral loads", Indian Geotechnical Journal, Vol. 10, No. 1, 232-244, 2013.
  6. Prakashm C. and Ramakrishna, V., “Lateral Load Capacity of Under-reamed Piles: An Analytical Approach,” Journal of Soils and Foundation, Vol. 44, No. 5, 51-65, (2004),
  7. Prakash, C. and Chandra, R., “Lateral Resistance of Single Under-reamed Piles in Silty Sand,” proc. Indian Geotechnical Conference, IGC-83, Madras, India, (1983).



  1. Martin, R. E. and DeStephen, R. A., “Large Diameter Double Under-reamed Drilled Shafts”, Journal of Geotechnical Engineering, Vol. 109, No. 8, 1082-1098, (1983),
  2. Peter, J. A., Lakshmanan, N., and Devadas Manoharan, P., “Investigations on the Static Behavior of Self-Compacting Concrete Under-reamed Piles,” Journal of Materials in Civil Engineering, Vol. 18, No. 3, 408-414, (2006)
  3. Shrivastava, N. and Bhatia, N., “Ultimate Bearing Capacity of Under-reamed Pile–Finite Element Approach,” in The12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), 1-6, (2008).
  4. Farokhi, A. S., Alielahi, H., and Mardani, Z., “Optimizing the Performance of Under-reamed Piles in Clay using Numerical Method,” Electronic Journal of Geotechnical Engineering, Vol. 19, 1507-1520, (2014).
  5. Vali, R., Mehrinejad Khotbehsara, E., Saberian, M., Li, J., Mehrinejad, M., and Jahandari, S., “A Three-Dimensional Numerical Comparison of Bearing Capacity and Settlement of Tapered and Under-reamed Piles,” International Journal of Geotechnical Engineering, Vol. 13, No. 3, 236-248, (2019)
  6. Watanabe, K., Sei, H., Nishiyama, T., and Ishii, Y., “Static Axial Reciprocal Load Test of Cast-in-Place Nodular Concrete Pile and Nodular Diaphragm Wall,” Geotechnical Engineering Journal of the SEAGS & AGSSEA, Vol. 42, No. 2, 11-19, (2011).
  7. Niroumand, H., Kassim, K. A., Ghafooripour, A., and Nazir, R., “Uplift Capacity of Enlarged Base Piles in Sand,” Electronic Journal of Geotechnical Engineering, Vol. 17, 2721-2737, (2012).
  8. George, B. E., and Hari, G., “Numerical Investigations of Under-reamed Piles.” Proceedings of Indian Geotechnical Conference, IGC-2016, IIT Madras, Chennai, India (2016).
  9. Helwany, S., Applied soil mechanics with ABAQUS applications. John Wiley & Sons, 2007.
  10. Karthigeyan, S., Ramakrishna, V., and Rajagopal, K., “Numerical Investigation of the Effect of Vertical Load on the Lateral Response of Piles,” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 133, No. 5, 512-521,(2007)
  11. Huang, A.B., Hsueh, C.K., O'Neill, M.W., Chern, S., Chen, C., “Effects of construction on laterally loaded pile groups”. Journal of Geotechnical and Geoenvironmental Engineering. ASCE;127(5):385-97, (2001).
  12. Marchetti, S., "The flat dilatometer: design applications". In: Proc III geotechnical Engineering Conference, Keynote Lecture, Cairo University; 1-26, (1997).
  13. Conte, E., Troncone, A., Vena, M., “Nonlinear three-dimensional analysis of reinforced concrete piles subjected to horizontal loading”, Journal of Computers and Geotechnics, Vol.49 (2013)123–133,
  14. Madhusudan Reddy, K. and Ayothiraman, R., “Experimental Studies on Behavior of Single Pile under Combined Uplift and Lateral loading,” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 141, No. 7, p. 4015030, (2015)
  15. Shanker, K., Basudhar, P. K., and Patra, N. R., “Uplift Capacity of Single Piles: Predictions and Performance,” Geotechnical and Geological Engineering, vol. 25, no. 2, pp. 151–161, (2007)