Computational continuum models of piles embedded in disturbed zones are developed using the Boundary Element Method (BEM) for application to three-dimensional dynamic soil-pile group interaction in layered soils. The enhanced 3D BEM code BEASSI is validated for handling pile group problems by comparison with reference solutions. A general sub-structuring formulation is developed to calculate theoretical accelerance functions. A 3D disturbed-zone computational model is then extended to handle the dynamic response of a typical 2 × 2 pile group. The performance of the model is illustrated through convergence studies and a case study corresponding to full-scale field tests. The results indicate strong frequency-dependent pile-soil-pile interaction by impedance functions, group efficiency ratios, and pile deformations. The findings from this study provide new insights into dynamic soil-pile group interaction, and the general approach can be used to examine other pile and soil conditions.