Evaluation of bearing capacity with time for small-scale piles driven into Leda clay

An experimental program was developed to study the evolution of pile capacity with time for piles driven into a type of sensitive marine soil known as Leda clay in eastern Canada. A variety of scaled piles were driven into undisturbed Leda clay and their shaft capacity was measured immediately after driving, and repeated at appointed elapsed time intervals. Results show pile capacity increases ranging from 60 to 230% of their initial values, 12 days after initial pile driving. A large proportion of this pile capacity increase over time, also known as setup, was generated within the first day due to fast excess pore water pressure dissipation, and afterward, the pile capacity increased at a lower rate. The pile setup rate was shown to be slightly higher for concrete piles compared to steel piles, possibly due to higher moisture absorbance. The research also revealed that pile setup for displacement piles is slightly higher than that of non-displacement piles.