Analytical solutions to interaction factors of two unequal length piles under horizontal loads

The technical note presents analytical solutions to interaction factors of two unequal length piles (ULPs) under horizontal loads by using the fictitious pile method. The bending moments along the fictitious piles and the horizontal displacements of the pile heads/bottoms were obtained based on a simplified Fredholm integral equation of the second kind. The proposed analytical solutions were validated against the three-dimensional finite-element simulations considering different pile slenderness ratios. Parametrical studies were then conducted to show the influence of some key parameters on the pile-to-pile interaction factors for ULPs.