Performance Evaluation of SPT-based Design Methods for the Axial Capacity of Driven Piles in Glacial Deposits

This paper presents an evaluation on the performance of seven SPT-based design methods for the axial capacity of steel piles driven in glacial deposits. This study is based on a database of pile load tests conducted in the province of Ontario, Canada. First, the performance these SPT-based design methods was evaluated for a total of 52 driven steel H or pipe piles. Most methods overpredicted on average by a factor of 1.01 to 2.14 with a large coefficient of variation (COV) ranging from 58.3 % to 97.4 %. Then, resistance factors for the ultimate limit state were calibrated using Monte Carlo simulation for these methods. The resistance factors are found to be generally low, ranging from 0.05 to 0.66. This study shows the risks and challenges of a pile design in glacial deposits.