AbstractThe earthquake-induced pressures on arrays of cylinders have received less concern, although pile groups have been widely adopted in real practice. This paper develops an analytical method to investigate the interaction of water with arrays of rigid circular cylinders subjected to horizontal ground motion. According to seabed and surface boundary conditions and using the variable separation method, the three-dimensional governing equation of water is first transformed to a two-dimensional Helmholtz equation in the xy-plane and analytical vertical modes in z-direction. Then, the analytical solution of the hydrodynamic pressures on arrays of cylinders is deduced. This analytical solution includes the radiated wave pressures generated by each cylinder due to the ground motion, first-order scattered wave pressures due to the radiated waves, and high-order scattered wave pressure due to diffracted waves. The finite-element method is employed to validate the present analytical solution. The results show that the analytical solution agrees well with the numerical solution. The proposed method is finally used to investigate the earthquake-induced hydrodynamic forces on linear arrays of circular cylinders.