Volume 27, Issue 1 (January 2004)
Effect of Pile Installation Method on Pipe Pile Behavior in Sands
Open-ended pipe piles are often used for the foundations of both land and offshore structures because of their relatively low driving resistance. In this study, calibration chamber tests were conducted on model pipe piles installed in sands with different soil conditions in order to investigate the effects of the pile installation method on penetration parameters and bearing capacity. Results of the test program showed that both the hammer blow count necessary to install the piles and the incremental filling ratio (IFR), which is used to indicate the degree of soil plugging in open-ended piles, decreased (1) with increasing hammer weight for the same driving energy, and (2) with increasing hammer weight at the same fall height. The base and shaft load capacities of the piles were observed to increase (1) with increasing hammer weight for the same driving energy, and (2) with increasing hammer weight for the same fall height. It was also observed that the noise level observed during pile driving decreases (1) as the driving energy decreases and (2) as the hammer weight increases for the same driving energy. Model jacked piles were also installed and tested. The jacked piles were found to have higher bearing capacities than identical driven piles under similar conditions, mostly due to the more effective development of soil plugging in jacking than in driving.