Bridge Surface Roughness Identification Based on Vehicle–Bridge Interaction

As the surface roughness of a bridge has significant influence on the interaction between a moving vehicle and the bridge itself, it is one of the hurdles for the use of the drive-by technique in the assessment of bridges. Proper identification of the surface roughness of a bridge will help minimize the associated uncertainties and improve the accuracy of numerical simulation. This paper presents a method for estimating the surface roughness profile from the responses extracted from a vehicle instrumented with accelerometers passing on the bridge tested. By letting the vehicle run along the bridge multiple times with different added masses, an estimation of the roughness profile can be obtained based on the vehicle–bridge interaction theory. No baseline data is required. Three simplified vehicle models have been used in this study, i.e. spring–mass model, spring–damper–mass model and half-vehicle model. The feasibility and effectiveness of this method are evaluated by finite element simulation with a simply supported bridge and a continuous bridge. The performance of this method for different levels of road surface roughness is assessed by suitable error indicators. A parametric study about the influence of vehicle and bridge parameters, measurement noise and structural damage on the identified results have been carried out.