Experimental study of moving force identification on a continuous bridge

This paper describes an experimental study on the identification of moving vehicle axle loads on a continuous supported bridge based on the measured bending moment responses. A bridge-vehicle system model was fabricated in the laboratory. The bridge was modeled as a three span continuous supported beam and the vehicle was modeled as a vehicle model with two-axle loads. A number of strain gauges were adhered to the bottom surface of the beam to measure the bending moment responses. Using measured bending moment responses as an input, the inverse problem was solved to identify moving loads. The moving forces were identified when considering bending moment responses from all spans of the beam and only one span respectively. The rebuilt responses were reconstructed from the identified loads as a forward problem. To study the accuracy of the method the relative percentage errors were calculated with respect to the measured and the rebuilt bending moment responses. The rebuilt bending moment responses obtained from the identified forces are in good agreement with measured bending moment responses. This indirectly shows that the method is capable of identifying moving loads on continuous supported bridges.