ISOLATIONS OF PLANE P AND SH WAVES BY BARRIERS COMPOSED OF SEVERAL ROWS OF CYLINDRICAL CAVITIES
The conformal mapping method of complex functions and expansion methods of wave functions were adopted,the coupling scattering properties of P wave and SH wave were considered,the boundaries of the cavities without radial formal stresses and shear stresses were assumed to be free,and then the theoretical solutions for the two-dimensional multiple scattering problems of incident plane P and SH waves were obtained by the discontinuous barriers composed of several rows of cylindrical cavities.By studying the normalized displacements which are the ratios of the displacements caused by both the incident and scattered waves to those only by the incident waves,the isolation effects of the barriers composed of several rows of cylindrical cavities were analyzed,which were also compared with those of a row of rigid piles,and some important conclusions were drawn out.They are:(1) the isolation effects increase with the rows of cylindrical cavities,and(2) in order to get better isolation effects than that of a row of rigid piles with the same radius,the space distance and total barrier width to cylindrical cavities,two rows of cylindrical cavities are needed for incident P waves,and three rows for SH waves.And these conclusions provide some theoretical basis and references for the vibration isolation design of several rows of cylindrical cavities.