Selecting scour monitoring devices for smart infrastructure

Abstract

Scour is a cause of the failure and often subsequent collapse of many bridge structures. Therefore, owners and operators of hydraulic structures such as bridges need to appraise the scour risk to these important infrastructure assets. To determine if scouring has affected a bridge, visual inspection data is still commonly used by bridge engineers. However, this approach has various limitations, e.g. operations cannot be undertaken safely by human divers during flood events and visual inspection may sometimes yield inaccurate data about scour extent due to e.g. refilling of scour holes overtime. Early detection of the onset of scour can ensure time for intervention and for the planning of alternative transport routes and thus some of the network service losses during and immediately after extreme weather events can be avoided. To have access to reliable data on scour, it is important to specify and deploy monitoring equipment for detecting the rate and extent of scour. In this paper, an updated framework to assist engineers with the selection of the most suitable instrument or instruments for monitoring scour around riverine bridges is presented. The existence of different types of monitoring devices and approaches requires a framework for selecting the most proper device for a specific field site or sites, as each device has its benefits and challenges with regards to, for instance: purchasing costs; ease of installation; maintenance requirements; operational resilience against debris/ice and provision of accurate data. The proposed framework was developed after an extensive review of other scour monitoring device selection frameworks. Then a pilot study was conducted at the University of Bristol to refine the framework which has now been tested by undertaking a series of interviews with practitioners. The results of the preliminary testing of the new framework are presented in detail in this paper. The paper concludes with recommendations for how rating frameworks can be used as part of the efforts to transition to ‘smarter infrastructure’.