Evaluation of Load Rating and System Reliability of Movable Bridge

Structural health monitoring (SHM) techniques can provide effective complementary means for the current bridge management system by reducing the uncertainty and by seamlessly integrating with state-of-the-art data management and Internet-based communication systems through information technology. However, SHM applications and studies do not fully exploit either statistical analysis of the collected data or structural reliability on the basis of sensor information. These additions can greatly enhance SHM to allow for more accurate and efficient data analysis, to predict future conditions, and to minimize life-cycle cost. An analytical simulation was set up with a field-validated finite element model (FEM) of an existing movable bridge to demonstrate how component and system reliability analysis can be performed. The validation of the FEM was performed with the use of the monitoring data from the bridge balance tests as well as a load test with a specialized truck. The validated model was then analyzed to estimate the load rating and reliability of the system when the model was loaded under HL-93 load (lane load and moving design truck). The load rating at critical locations and bridge system reliability as a function of truck location are presented.