| A new Bridge Weigh-in-Motion (B-WIM) method is developed for identifying a set of moving truck data using only a sparse set of strain measurements. Speed, number of axles, and axle distances were identified directly from the first derivative of the measured strain. Axle weights and truck gross weight were obtained by using numerical optimization to match the zero slope point of the analytical truck influence line generated from a finite element model for the same strain measurements. Truck path was identified using bridge girder distribution factors. This method was validated with simulated known truck responses, verified using a full-scale bridge diagnostic load tests measured strains, and used for unknown truck identification using bridge operational (response only) measured strains. The method proved to be promising by its successful application to simulated bridge responses, diagnostic load tests, and operational strain measurements. The proposed B-WIM can be used by bridge owners and highway officials for monitoring unknown truck weights as a bridge management tool. |
