Nine Wells Bridge – Cambridgeshire, England – August 2009
The Nine Wells Bridge in Cambridgeshire marked the first international deployment of the WSS bridge monitoring platform as well as the first installation on a prestressed concrete bridge span. The Nine Wells Bridge is a newly constructed facility with three spans totaling just under 90 meters. The bridge features a reinforced concrete deck supported by twelve prestressed reinforced concrete beams.
Thirty dual-axis accelerometers were interfaced with the 30 wireless sensor nodes to record the ambient vibration response due to traffic excitation. Reference-based testing was utilized to obtain ultra-high spatial density of the mode shapes. Despite numerous sensor configurations, the testing was performed expediently as facilited by the ease of the highly mobile wireless platform. Twelve global modes as well as an additional seven span-specific modes from the high-density reference-based deployments were reconstructed to provide an extensive database for subsequent structural identification. The study was followed up with structural identification through finite element (FE) updating to develop an analytical model with boundary conditons tuned to the measured response.
Associated Journal Papers
Whelan, M.J., Gangone, M.V., Janoyan, K.D., Hoult, N., Middleton, C.R., and Soga, K. (2010) “Wireless Operational Modal Analysis of a Multi-Span Prestressed Concrete Bridge for Structural Identification,” Smart Structures and Systems 6(5-6)