Field testing of indirect displacement estimation using accelerometers

Displacement measurements of structures like bridges are helpful in many ways. Understanding bridge response to increasing loads is of interest in bridge analysis and load rating. Currently used direct displacement methods such as laser systems and displacement transducers are expensive, time consuming and difficult to deploy, particularly on an in-service bridge. One indirect method would be to use accelerometers to obtain displacement by directly integrating twice. Accelerometers are inexpensive and easy to deploy; however noisy measurements render such a technique infeasible. We propose a novel solution using signal models in adaptivesized blocks with automatic order detection to obtain a clean acceleration signal that can be directly integrated twice to obtain the displacement. Our method was evaluated by conducting a test on an in-service concrete slab-on-steel girder bridge. Our results show that accurate displacements are determined from the measured accelerations.