Movable bridges: condition, modelling and damage simulations

Movable bridges are unique structures due to the complex interaction between their structural, mechanical and electrical systems. While these systems provide versatility to movable bridges, their intricate interrelation also creates intermittent operational and maintenance challenges. First, the authors examine movable bridges in Florida with their inspection data. The review of common problems serves as a basis for the selection of a real-life bridge and the simulations that are the main contributions of this particular paper. Next, the representative bascule-type movable bridge is described. As span lock failure is identified as one of the most frequently observed movable bridge problems, a finite-element model of the representative bridge is created to simulate this type of failure. Before conducting the span lock damage simulations, the finite-element model is calibrated globally using modal frequencies from ambient vibration tests and locally using strain data from field load tests. Finally, changes in the static and dynamic characteristics are examined to detect issues such as span lock failures, which are critical to ensure the safe operation of bascule-type movable bridges.