Pavement Dynamic Response by Stiffness Matrix Approach

The background and application of the stiffness matrix approach in the dynamic analysis of pavements and other layered systems is presented. The stiffness matrix approach involves a triple transformation of the problem. The first transformation is transformation of loading from the time to the frequency domain. The second and third are spatial transformations of loading, leading to the solution of the problem in the frequency-wave number domain. Finally, inverse transformations are used to return the pavement response to the original spatial-time domain. The most important advantage of the stiffness matrix approach is that the infinity (radiation condition) of the half-space and lateral boundaries is perfectly satisfied. The other advantage is that a single 4 x 4 (2 x 2) complex stiffness matrix provides a theoretically exact description of a single pavement layer (or a half-space). The method can be used for numerous purposes: in modeling and analysis of the response of a pavement to dynamic loads, simulation of nondestructive tests like falling weight deflectometer (FWD) and wave propagation based tests (e.g. Spectral Analysis of Surface Waves — SASW), evaluation of dynamic characteristics of pavement systems (natural frequencies and damping characteristics), etc. The results presented include the dynamic response of pavements to wheel loads, for the purpose of prediction of vibration (deformation) levels, and to small radii circular sources, for simulation of nondestructive pavement testing.