STUDY ON THE EFFECT OF BARRIER OF A ROW OF RIGID HOLLOW PIPE PILES FOR THE ISOLATION OF P AND SH WAVES

The expansion method of wave functions and Graf’s addition theorem are adopted, the equilibrium conditions of the total stresses and torques at the boundaries of rigid piles and soils are considered, and theoretical solutions of scattering coefficients for incident plane P wave and SH wave by the barrier composed of a row of rigid hollow pipe piles are obtained. The concepts of normalized displacements and transmissibility index are introduced. The contours of the normalized displacements behind the barrier of rigid hollow pipe piles with different wall thicknesses, the curves of transmissibility index changing with the distance between the piles and the curves of the normalized displacements changing with the number of piles are drawn. Then some important conclusions are obtained. For example, the vibration isolation effect of the barrier increases as the separations or the wall thicknesses of the rigid hollow pipe piles decrease, and the area of best vibration isolation effect increases as the number of piles increases, which provides a theoretical basis for the design of discontinuous barrier for vibration isolation.