Numerical Studies on Performance of Helical Pile-supported Embankments Over Soft Clay

The need for practical and economical solutions to increase the stability of embankments and reduce their settlement is a significant issues in geotechnical engineering. An effective approach to improve the overall performance of embankment systems is using structural elements such as piles. In recent years the use of helical piles has gained consideration due to their proper performance under compressive and tensile loads, quick and easy installation, and elimination of concreting problems. This study investigates the performance of embankments supported by helical piles through a 3D numerical study using the Abaqus software. The validation was performed according to the experimental and field data provided by other researchers. Then, 3D numerical models were developed to investigate the effects of pile caps, the ratio of helix diameter to shaft diameter, the number of helices, and the optimum spacing of helices. The finite element modeling results indicated that increasing the number of helices and changing their spacing had no significant impact on controlling the settlement. It was also found that the load transfer mechanism parameters had a direct relationship with the helix dimensions and shaft diameter. Adding helices to piles increased their bearing capacity, improving parameters of the load transfer mechanism, such that the arching in a pile with three helices decreased by 40% compared to the one with one helix. The results also revealed that on average, 80% of the load imposed on a pile was sustained by the shaft, and helices had a smaller effect on the settlement of pile-supported embankments.