Effect of compressive load on uplift of pile group in clay: Theoretical analysis

In this paper, analytical methods based on the concept of interaction factor have been proposed for line pile groups (2 x 1 and 3 x 1) under pure uplift and uplift subjected to 25% static compressive load. The parameters considered in this analysis are L/d ratios, spacing of pile groups, group size and shape. Theoretical results in the form of the interaction factor 'alpha' for group of piles are presented for different L/d ratios and Poisson's ratios. Results obtained are compared with the reported experimental results of single pile. For any L/d ratio, the interaction factor 'alpha' of line pile groups under uplift subjected to 25% compressive load decreases with increase in spacing between the piles. The interaction factors proposed for 2 x 1 and 3 x 1 pile groups can be used to determine the settlement of pile groups under uplift subjected to 25% of static compressive load.