Study of Rayleigh Dispersion Curves Calculation for Pavement Systems

The shear wave velocities of pavement systems decrease with depth, and their dispersion curves can be obtained by the stiffness matrix approach or the finite element method, etc. For pavement systems, searching for the roots of the frequency equation is beset with difficulties. The roots are mostly complex numbers and numerical overflow problems occur frequently. Through adding a high velocity layer under the sub-grade, then, the roots become real numbers. The influence is more and more weak with the thickness of sub-grade increasing. The new method is feasible from simulated results.