Dynamic bridge weigh-in-motion using estimated modal parameters from ambient vibration tests

Dynamic bridge weigh in motion systems use models that can simulate the dynamic behaviour of a bridge subjected to moving traffic. Currently available models use complex and computationally expensive Moving Force Identification (MFI) methods that utilize finite element models to estimate the bridge torsional and transverse dynamic behaviour. This paper presents a novel dynamic parametric BWIM method that utilizes the experimentally estimated modal parameters for simulating the response of a bridge structure to moving loads. The estimated modes of an in-situ structure inherently capture the true bridge behaviour for any generalized geometry, boundary conditions and load position. Therefore, it enables the complex torsional and transverse bending behaviour of the bridge to be captured. In this paper, the mathematical derivation of the analytical model is presented in detail, then model calibration and weighing procedures are outlined, followed by the validation of the proposed method using a full-scale case study arterial highway bridge in the Canadian Province of New Brunswick. The proposed dynamic BWIM method offers a novel solution for the development of real-time BWIM systems that is efficient to calibrate and accurate in vehicle identification.