PileGroup is a finite-element based program which has been developed to calculate the deformations and loads of pile groups subject to general three-dimensional loadings such as axial and lateral forces and moments applied on the pile caps. The individual piles within the pile group can be vertical or on a batter with the connection between pile heads and pile cap to be fixed, pinned, or elastically restrained by rotational springs.

P-Y curves for weak rock in the PileLAT program are calculated using the method proposed by Reese (1997) and shown in the figure below.