Effect of Compressive Load on Uplift Capacity of Pile Groups in Sand

Abstract

An experimental cum analytical study has been carried out to quantify the effect of compressive load due to stage construction on uplift capacity of model pile groups embedded in sand. Pull out tests were conducted by placing a static compressive load of 0, 25, 50, 75, and 100% of their ultimate capacity in compression on pile groups of different configuration and length to diameter ratio embedded in sand. The experimental results indicated that the presence of compressive load on the pile group decreases the net uplift capacity of the group and the decrease depends on the magnitude of the compressive load. Based on the experimental results a semi empirical method has been suggested to predict the net uplift capacity of a group of piles in the presence of compressive loading. The predictions are found to be in good agreement with the measured values validating the developed method of analysis.