Assessment of the Theoretical Methods to Estimate the Tension Load Capacity of CFA Piles

This paper studies the behavior of three continuous flight auger piles executed in unsaturated soil subjected to tension forces. Field tests and laboratory tests were conducted on representative samples collected from a borehole 17m deep. The water table does not exist until a depth of 17m. The author carried out slow static load tests to check the behavior of the piles when subjected to tension forces. The tension capacity of these piles was also investigated using theoretical methods and semi-empirical approaches. The author compared the values estimated from the theoretical and semi-empirical methods considered with those obtained using field load tests. One of the tested piles was loaded until removal from the soil to investigate its geometry. The results showed that the theoretical methods give higher values compared with static load tests, while semi-empirical methods give low estimates.

Keywords: Tension piles; Flight auger; Field tests