Experimental and Numerical Study on the Bearing Capacity of Tapered Piles in Sand Under Compressive Load

Deep foundations are widely recognized as one of the most effective methods for transferring surface loads to subsurface soil layers. While cylindrical piles are the conventional choice for deep foundations, tapered piles offer significant advantages in load transfer and material efficiency. This study investigates 12 types of tapered piles with varying characteristics in the loose and dense soils under static loading conditions in both loose and dense sands through laboratory experiments. The behavior of tapered piles is also modeled numerically using finite difference analysis, and the numerical results are validated against the experimental data. Additionally, a parametric analysis is conducted to evaluate the influence of design variables such as taper angle, pile length and sand relative density on the load-settlement behavior. The comparative analysis between tapered and cylindrical piles identifies an optimal taper angle for homogeneous sands, revealing that the bearing capacity decreases by 2.86 degrees with an increase in pile angle. Moreover, increasing the relative density of the soil results in a 2- to 3-fold improvement in the bearing capacity of the piles.