Scientia Iranica | 2021
Dispersion curves for media with lateral-variation at different angles
Abstract
In recent years, the studies have been focused on using the surface wave methods in determining the soil specifications. The surface layer of the soil with lateral variation was modeled at different angles in finite element software. The shot was applied on two sides of the geophone array and the seismic wave data were recorded by geophones. Using the windowing methods of different lengths and moving along the array, the various geophone data were placed in different windows. Next, for each windowing, the frequency-wavenumber spectrum was obtained using the double Fourier transform and then, the dispersion curve was plotted. In this regard, the variations in the resolution of frequency-wavenumber spectrum and dispersion curve were investigated for different window lengths. The results show that for the media with lateral variation at different angles, the dispersion curves could be obtained along the array and the location of the start and end of lateral variation along with the corresponding phase velocity range could be achieved with an acceptable accuracy, and the estimated phase velocity could be used as initial velocities in the inversion and specification of soil surface layers.