Efficient Backcalculation Algorithm of Time Domain for Large-Scale Pavement Systems Using Ritz Vectors

Abstract

This paper describes a backcalculation algorithm to determine the layer moduli and damping coefficients in the time domain for large-scale pavement structures. Pavement is modeled by three-dimensional finite element (3D FE). The parameter identification procedure makes use of the Ritz vector method to reduce the size of matrices involved in the forward dynamic response analysis and the deflection sensitivity analysis. The responses of the reduced equation system are obtained in the time domain using the direct integration method. The parameter estimates are improved iteratively by means of an algorithm that calls the finite element program of transient response analysis as a subroutine combining singular value decomposition (SVD) method. The system constructed in this manner is applied to two experimentally tested sections of pavement, which are modeled by 3D FE, in order to verify its effectiveness. All parameters are determined using the surface deflection-time histories of pavement experimentally recorded from the falling weight deflectometer (FWD) tests at the sensor locations.