ANALYTICAL SOLUTION OF THE NEAR FIELD VIBRATION ISOLATION EFFECT OF PIPE PILE BARRIERS UNDER A CYLINDRICAL WAVE SOURCE

Based on the wave function expansion method of expressing the free field of cylindrical wave source, an analytical method for solving the vibration isolation effect of pipe pile barriers on elastic waves under a cylindrical wave source is proposed for the first time. In the method, considering the position relationship between the cylindrical wave source and the pipe pile barrier, the incident cylindrical wave was expressed by the 0-order Hankel expansion using the wave function expansion method, and expressed in any pile coordinate system using Graf addition theorem of transformation between arbitrary coordinate systems. After superposing the incident wave field and the scattered wave field, the scattered wave field of all piles was solved by satisfying the boundary conditions of all piles. The analytical method is used to analyze the vibration isolation effect of pile group barriers under the incidence of cylindrical wave source. The influence of the incident wave curvature is considered in the vibration isolation problem of row piles for the first time, which provides a theoretical solution for the scattering problem of cylindrical waves. The results show that the isolation effect of pipe pile barrier on cylindrical P-waves is generally better than that on cylindrical SV waves; When the cylindrical wave source is closer to the pipe pile barrier, the displacement response of the pile behind the pile increases significantly; Compared with a plane wave source, the number of piles under the action of a cylindrical wave source decreases; The isolation effect of three-row pipe pile barriers is stronger than that of two-row pipe pile barriers, so three-row pipe pile barrier is more suitable for the vibration isolation of a cylindrical wave source.