TORSIONAL OSCILLATIONS OF A RIGID DISC ON SATURATED POROELASTIC GROUND

Characteristics of torsional oscillations of a rigid disc on saturated poroelastic grounds are studied by analytical method for the first time. The dynamic governing equations for saturated poroelastic media are solved by means of Hankel transform. According to the mixed boundary-value conditions, the dual integral equations of torsional oscillations of a rigid disc resting on saturated poroelastic ground are established, which are further reduced to Fredholm integral equations of the second kind. The dynamic compliance coefficient curves and the torsional angle amplitude of a rigid disc versus the dimensionless frequency are presented. Numerical results indicate that, compared with the dynamic response of a rigid disc bearing on elastic half space, the presence of pore water has some effects on the characteristics of torsional oscillations of a rigid disc resting on saturated media and can reduce the dynamic response around the resonant frequency, especially when the soil permeability is very good.