| Abstract: | The dynamic behaviour of a finite number of rigid, adjacent foundations on the surface of a linear-elastic, isotropic and homogeneous halfspace due to a far-field excitation of the Rayleigh type is the subject of the present work. The dynamic behaviour of this system differs from that of a single foundation subjected to the same excitation due to the existence of the natural coupling between adjacent foundations caused by the wave propagation through the underlying soil. For the determination of the diffraction forces acting on the foundations an analytical procedure is followed. The stresses at the interfaces between the foundations and subsoil are approximated by series expansions of orthogonal polynomials. It is interesting to notice that, apart from the loads appearing in the direction of incidence, additional loads perpendicular to the given incidence direction act on the foundations due to scattered waves. Their intensity depends on the excitation frequency and the distance between the foundations. The method followed here can be applied for the determination of the dynamic loads acting on fixed foundations in the case of a seismic excitation of relatively long duration. |
