Route 345 over Big Sucker Brook – Waddington, NY
The RT345 Bridge over Big Sucker Brook in Waddington was an end-of-service life highway bridge scheduled for replacement and closed to traffic that provided a unique platform for assessing the performance of a heavily deteriorated structure as well as the response under prescribed, progressively applied known damage. Various tests were performed over nearly a week of on-site investigations culminating with the final day in which damage was introduced to the structure.
Ambient vibration monitoring was performed using thirty dual axis accelerometers interfaced with the wireless sensor nodes and distributed across the three simply-supported spans. Seperate testing was performed with the sensors placed on the girders and then on the deck surface to investigate the differences in data quality and richness associated with sensor placement.
Diagnostic Load Testing and Capacity Rating
Diagnostic load testing was performed using 39 strain transducers installed across the entire structure and two trucks with known axle weights. Distribution factors from various load cases, neutral axis and section modulus estimates, and end fixity measures were obtained from the static load cases. Truck passes with incremental speed increases were also applied to gauge the dynamic impact factors over typical traffic speeds. The end-of-service load capacity was estimated using the results of the diagnostic load test and analytical/geometric relationships.
Prescribed Damage Testing
On the final day of testing, thirty dual-axis accelerometers and twenty strain transducers were installed on the northern-most span of the structure. Following acquisition of baseline response meaurements, bearing restraint conditions were impacted at a high-rocker bearing using a hydraulic jack over various levels of reaction pressure. Traffic excitation was used to record the ambient vibration response following damage introduction and static truck loads were positioned in three lane configurations to gauge the strain-based response. In addition to the simulated bearing damage, connection bolts between girder and diaphragm elements were progressively removed to introduce another damage scenario to the bridge.
Associated Journal Papers
Whelan, M.J., Gangone, M.V., and Janoyan, K.D. (2009) “Highway Bridge Assessment using an Adaptive Real-Time Wireless Sensor Network,” IEEE Sensors 9(11), 1405-1413.
Whelan, M.J. and Janoyan, K.D. (2010) “In-Service Diagnostics of a Highway Bridge from a Progressive Damage Case Study,” Journal of Bridge Engineering 15(5), 597-607
Gangone, M.V., Whelan, M.J., and Janoyan, K.D. (2011) “Diagnostic Load Testing and System Identification Using Wireless Sensors,” Computer-Aided Civil and Infrastructure Engineering 26(7), 560-579