Integral Transform Method (ITM) could be used for problems of wave propagation in medium such as soil - an elastic halfspace. The method is based on an analytical solution of the equations of motion, obtained by transforming the system of equations from the time-space (original) domain to the frequency-wavenumber (transfomed) domain using Fourier transforms. The system of partial differential equations is transformed to the system of algebraic equations with complex coefficients. The solution of the system is the displacement field of the halfspace in the transformed domain. The displacement field in the original domain is obtained by using inverse Fourier transform.
ITM could be used for the analysis of the response of the halfspace due to stationary or moving oscillatory load.