Load Testing and Assessment of Bridge with Unknown Foundations
The Division of Highways of West Virginia Department of Transportation (WVDOT) identified a subset of their bridge inventory posted for load rating that required advanced testing for assurance that the structures could safely sustain repeated overloads. Upon selection of a single bridge from the subset, Intelligent Infrastructure Systems had three main responsibilities for this project: (1) facilitating the test through on-site coordination and support, (2) development of a 3D finite element model of the bridge, design of an instrumentation plan for traditional live load testing on the structure, and execution of that testing, and finally (3) implementation of the THMPER™ (Targeted Hits for Modal Parameter Estimation and Rating) and RAMPS systems.
THMPER™ combines a self-contained rapid modal testing trailer and streamlined data processing software to extract modal parameters. RAMPS builds and updates a finite element model, leaving the user with a reliable model updated with field-collected data in a fraction of the time required for traditional impact testing.
Intelligent Infrastructure Systems and Drexel University executed the modeling and live load testing which served as the baseline comparison for the implementation of the THMPER™ and RAMPS. THMPER™ was deployed on the Mossy Creek bridge, requiring only thirty minutes of traffic interruption in total to collect data from the entire bridge. The extracted modal parameters were used to calibrate a finite element model and provide revised load ratings for the Mossy Creek Bridge to WVDOT. Additionally, the calibrated model from traditional live load testing was compared to the results from the THMPER™ testing with agreeable conclusions.