Monitoring of infrastructure at risk of scour and other hydraulic actions

Scour is a significant impact caused by climate change on infrastructure, while also being the most common cause of bridge failure worldwide. Approximately 60% of bridge collapses are a result of scour (Briaud and Hunt, 2006; Wardhana & Hadipriono, 2003).

Climate change has resulted in the increase of extreme weather events, such as wildfires and floods among others. Global warming is evident, sea levels are rising, and the frequency and magnitude of flood events is increasing. As the climate is changing, the risk of scour is expected to increase further.

Monitoring is crucial for the identification of scour taking place around a structure, its magnitude, as well as the rate of deterioration to allow owners and operators to establish when predetermined thresholds are at risk of being reached. Scour monitoring is crucial to safeguard infrastructure that could be exposed to scour action.

According to the Design Manual for Roads and Bridges BD 97/12 Standard entitled ‘The assessment of scour and other hydraulic actions at highway structures’, scour monitoring techniques can be divided in the following categories (Highways Agency, 2012):

• Measuring the maximum scour level that has taken place;
• Measuring scour development adjacent to a structure during high flow events;
• Methods correlating with scour development, such as water level monitoring, flow velocity monitoring and weather warnings.

Scour monitoring techniques are mainly reactive. This study compares existing and emerging scour monitoring methods, exploring a combination of scour monitoring sensors at structures at risk of scour.  The introduction of a new, innovative sensing platform for scour monitoring is discussed, linking the new sensor package to the asset health management platform using telematics, enhancing the understanding of scour taking place through accurate visualisation. This method facilitates more proactive monitoring of scour, the collection of data necessary for the design and implementation of scour protection measures, and innovative, more accurate scour prediction.

References:

Briaud JL and Hunt BE (2006) Bridge scour and the structural engineer. Structure Magazine, December: pp. 57–61.

Highways Agency, Transport Scotland, Welsh Government and Department for Regional Development Northern Ireland, UK (2012) Design Manual for Roads and Bridges. Highway Structures: Inspection and Maintenance. Volume 3, Section 4, Part 21. BD 97/12. The Assessment of Scour and Other Hydraulic Actions at Highway Structures. The Stationery Office, London, UK.

Wardhana K and Hadipriono FC (2003) Analysis of recent bridge failures in the United States. J. Perform. Constr. Facil. 17 (3): 144–150. https://doi.org/10.1061/(ASCE)0887-3828(2003)17:3(144)