ABSTRACT
Bridge weigh-in-motion (BWIM) system uses the bridge as a scale to estimate vehicle weights. For BWIM systems, reliable axle detection is a prerequisite for the accurate identification of axle weights and GVW. The existing nothing-on-road (NOR) BWIM systems typically use additional sensors, such as the free-of-axle-detector (FAD) sensors, for axle detection. However, these NOR axle detection strategies were reported to be only suitable for certain types of bridges and susceptible to wheel transverse positions. In this study, a equivalent shear force (ESF) method is proposed to identify vehicle speed and axle spacing by using the flexural strain signal recorded from the weighing sensors. Compared to the existing NOR BWIM systems, the proposed method does not require additional sensors for axle detection, which reduces the cost and facilitate the installation of BWIM systems. The effectiveness and accuracy of the proposed method are demonstrated through numerical simulations using three-dimensional vehicle-bridge coupled analysis.
