ABSTRACT
Infrastructure (including bridges, viaducts and embankments) built in or near rivers, estuaries or coastal regions are vulnerable to scour. Scour undermining of piers or abutments during floods is the most common cause of bridge failure, and can result in loss to life, disruption to transport and economic losses. The factors influencing development of scour are complex and vary according to a wide range of elements (e.g. structure, local geology and sediment type, river morphology, flow and weather conditions). Understanding the potential for scour is key to managing the risks associated with this and in maintaining infrastructure operative for a large portfolio of bridges. Traditional methods of detection of scour are time- and resource-consuming, and could lack in accuracy and timeliness. As scour events can happen over relatively short periods of time (for example during flooding), implementing continuous monitoring is one strategy to detect scour in a more effective way. Several technologies for scour monitoring have been available in recent years, but implementation of these is not straightforward. This paper aims at exploring the potential for eight continuous technologies to monitor scour for railway bridges, to implement mitigation measured in a more targeted and efficient manner. Sonar, Time Domain Reflectometry (TDR), Fiber Bragg Grating Sensors (FBGS) and electromagnetic probe are the four technologies considered for direct measurements. MEMS Tilt Sensors, accelerometers, pressure transducers (water level sensors) and ultrasonic water level sensors are the four technologies considered for indirect measurements. The eight methods are evaluated against site specific constraints for practicality of installation on three structures of interest in the Western UK, as case studies.
