Investigation of the factors affecting the ultimate bearing capacity of bridge piles in limestone with a calibrated 3D FEM

In this study, we investigated the behavior of a pile constructed on limestone rock under axial loading using a numerical approach. A parametric study was performed based on the full-scale pile load test results and the geotechnical reports on the site. Different values of unconfined compressive strength were implemented to investigate the pile’s behavior in relation to skin friction resistance only and the combination of end bearing and skin friction resistance. Additionally, we studied the effects of the length/diameter ratio on the pile’s capacity using nine pile load models. Numerical analysis showed that, in the initial loading stage, the applied load was transferred by skin friction only, until a certain displacement value, after which end bearing resistance shared the transferred load with skin friction resistance. Furthermore, there was a strong correlation between the load values measured using the finite element method and the values predicted from other methods used in the literature.