Experimental study on bearing behaviour of different uplift piles

Abstract

Based on pile load test results of uplift bored piles for a deep-embedded underground transformer substation, the uplift behaviour of enlarged toe pile and shaft post-grouting bored piles have been studied. The loading transfer characteristics and uplift capacity improvement mechanism for the two different type uplift piles have been investigated. The research shows that post-grouting can significantly improve bored pile uplift bearing capacity. After pile shaft grouting, the interface condition between pile and soil is improved, the friction resistance of pile side is increased obviously, and the uplift bearing capacity is improved. For long uplift pile, the uplift resistance of shaft grouting bored pile is better than that of enlarged toe pile.