Improved approach of super-long pile group considering multiple interaction under axial load

This work presents an improved approach to consider the effect of any intermediate piles between the two piles in pile groups. Based on the thin ring shear model of concentric cylinder and elastic theory, a multi-pile analysis model under axial load is proposed with full consideration of the mutual reinforcing effect between super-long piles. A theoretical derivation of interaction coefficient and the deformation of super-long pile groups which simultaneously consider the reinforcing effect and the existence of other piles in pile groups was carried out. Example analysis shows that the analytical solution agrees well with the experimental results. In this work, the error between the calculated result of the presented model and the measured value is 25% less than that in the traditional model. The multi-pile model fully analyzes the interaction mode between multiple piles and considers the mutual reinforcing effect among the piles, which makes up for the deficiency in traditional settlement calculation of pile groups. Consequently, the model proposed can accurately reflect the working characteristics of super-long pile groups in actual engineering. © 2021, Saudi Society for Geosciences.