Dispersion of Love waves in prestressed double-layered medium over a gravitating half-space

Love-type surface wave in a model comprising two prestressed layers over an inhomogeneous half-space under the influence of gravity is investigated. The considered uppermost prestressed layer is inhomogeneous having anisotropy of orthotropic type, whereas the lower prestressed layer is an anisotropic porous medium. The elastic constants and density of the upper layer and the gravitating half-space vary with the depth and this variation is defined by using trigonometric and exponential functions. Applying appropriate boundary conditions and using Whittaker’s function frequency equation is established, based on which numerical computations are carried out for a specific model, and graphs are plotted to depict the impact of different factors, e.g. inhomogeneity, initial stress, porosity, gravity and thickness proportion of the considered layers on the propagation of Love wave. It is found that there is profound impact of all these factors on the velocity of Love wave. The analytical derivations of the present paper may be useful to seismologists, structural engineers and those working in the field of geophysical prospecting and soil mechanics.