Field validation of a wireless structural monitoring system on the Alamosa Canyon Bridge

A state-of-art design of a wireless sensing unit, which serves as the fundamental building block of wireless modular monitoring systems (WiMMS), has been optimized for structural monitoring sensing applications. Employing wireless communications as a primary means of data transfer, the high-cost but fragile cables of traditional tethered monitoring systems is eradicated resulting in a low-cost yet flexible monitoring infrastructure. An additional innovation is the inclusion of advanced embedded microcontrollers to accommodate the computational tasks of engineering and decision support analysis. To quantify the performance of the wireless sensing unit, field validation upon a full-scale benchmark structure is undertaken. The Alamosa Canyon Bridge in New Mexico is instrumented with wireless sensing units and a traditional cable-based monitoring system in parallel. Forced vibrations are applied to the bridge and monitored using both (wireless and tethered) data acquisition systems. Recorded time-history measurements are used to identify the modal properties of the structural system. The performance of the wireless sensing units is compared to that of the commercial wire-based monitoring system.