Inversion Of The Driving Force Of The Flexible Pavement Material Properties

Pavement layer properties back-analysis based on Falling Weight Deflectometer (FWD) deflection is an important orientation of the future study for pavement nondestructive evaluation. Up to now, most of present back-analysis theories are based on quasi-static analysis method, in fact, the load of FWD is dynamic, so it is necessary to develop dynamic back-analysis. In this paper, pavement layer material properties back-analysis based on dynamic model is studied systemically, the main results are as follows:1. Based on the nonlinear least square optimization technique and singular value decomposition method, the back-analysis method based on dynamic model for estimating material properties is established. The theoretical results and test results show that this method is an efficient calculation approach that can converge to a solution quickly in a wide rang of initial values of modulus.2. The concept of equivalent damp is presented in the back-analysis and the feasibility of the method based on equivalent damp is proved. Thus the computational quantity could be reduced enormously.3. The data from the actual pavement is analyzed by the method based on the nonlinear least square optimization technique.The result of this article can apply to the real engineering.