Climate change impacts on railway structures: bridge scour

Abstract

Weather-related disruption is a pressing issue for transport infrastructure in the UK, which is expected to aggravate due to climate change. Infrastructure managers, such as Network Rail, need to adapt to these changes, tackling the challenges brought about by wide-ranging uncertainties from various sources. This paper explores the relationship between climate change and bridge scour, identifying barriers to sustainable adaptation. Scour is the removal of riverbed material at bridge foundations due to hydraulic action and is the foremost cause of bridge failure in the UK and worldwide. A model is developed that simulates the causal chain from climate change to scour risk. This is applied to four case study bridges in Wales and the south-west of England, quantifying the effects of climate change and tracing key uncertainties in the process. Results show that the current scour risk models in Network Rail may be insensitive to increases in risk due to climate change. One way to tackle this may be to introduce models to assess absolute risk; current scour risk models are used only for the prioritisation of vulnerable sites.

Three-dimensional mesoscale modelling of multi-span masonry arch bridges subjected to scour

“…Finally, no modelling strategies have been proposed thus far for describing the vulnerability of masonry arch bridges to scour. In this respect, it should be observed that arch bridges are often built on shallow footings, and that many procedures for scour risk assessment ( [11], [12]) assume that the bridge collapses when the maximum scour depth reaches the level of the foundation base. However, given the complexity of the problem, the non-symmetric shape of the scour hole, and the bridge redundancy, a 3D structural analysis of the soil-foundation-bridge domain is required to evaluate fully the effects of scour.…”

Identifying the Input Uncertainties to Quantify When Prioritizing Railway Assets for Risk-Reducing Interventions

“…Other researchers have focused on improving the understanding and modeling of one of those factors-i.e., risks, costs and effects on service-and for specific asset types. For example, [3] presents a detailed model that simulates the causal chain from climate change to scour risk related to the bridges of Network Rail. A detailed model to estimate risks related to railway accidents, when considering different environmental conditions is presented in [100].…”

“…There is a plethora of methods and models to estimate the risks due to railway asset failures, as well as the costs and effects on rail service due to failures and interventions. For example, [1][2][3][4][5][6][7][8][9][10][11][12] analyze the risk related to railways due to specific hazards. Many scholars have focused on the analysis of risk related to specific failure modes of the railway assets, e.g., [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

Risk-informed asset management to tackle scouring on bridges across transport networks

“…Several studies have developed empirical equations to predict the scour depths and have often linked the depth and rate of scour development on a given structure to the position and type of the structure; water flow conditions including water depth, flow velocity and water kinematic viscosity (Pizarro et al, 2020) and the characteristics of the material forming the bed and banks of the channel (Kirby et al, 2015). A detailed comparison of widely used scour models can be found in the literature (Dikanski, Hagen-Zanker, Imam, & Avery, 2017;Pizarro et al, 2020;Pizarro & Tubaldi, 2019).…”