The Science behind Scour at Bridge Foundations: A Review

Abstract

Foundation scour is among the main causes of bridge collapse worldwide, resulting in significant direct and indirect losses. A vast amount of research has been carried out during the last decades on the physics and modelling of this phenomenon. The purpose of this paper is, therefore, to provide an up-to-date, comprehensive, and holistic literature review of the problem of scour at bridge foundations, with a focus on the following topics: (i) sediment particle motion; (ii) physical modelling and controlling dimensionless scour parameters; (iii) scour estimates encompassing empirical models, numerical frameworks, data-driven methods, and non-deterministic approaches; (iv) bridge scour monitoring including successful examples of case studies; (v) current approach for assessment and design of bridges against scour; and, (vi) research needs and future avenues.

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

“…which bridge within the network to maintain) and the Table 1. Factors contributing to bridge scouring (Barbetta, Camici, & Moramarco, 2017;DMRB, 2012;Lamb et al, 2017;May et al, 2002;Pizarro et al, 2020).…”

“…1 in 20 bridges in the UK is expected to be at high risk of failure due to climate change by 2080(Dawson et al, 2018 and the scour risk mitigation expenditure alone is estimated to be e25-76 million annually for the period 2040-2100 (Nemry & Demirel, 2012). Scour occurs in three main forms (Kirby, Roca, Kitchen, Escarameia, & Chesterto, 2015;Pizarro, Manfreda, & Tubaldi, 2020): i. Natural scour occurs due to long term changes to the river channel and includes the aggradation and degradation of the riverbed that may occur as a result of changes in the flow rate or changes in the quantity of sediment in the channel.…”

Electromagnetic Sensors for Underwater Scour Monitoring

“…Scour initiates when the shear force at the water-bed interface is higher than the critical shear stresses corresponding to the initiation of motion of the soil particles [3]. The type of bed material also plays an essential role in the scour process as the critical shear stress is peculiar to it [4].…”

“…This outcome shows that empirical formulas embedded in current assessment procedures may result in overconservative scour estimates. This is mainly because they are based on laboratory tests under controlled conditions that are not representative of real ones (see e.g., [4]). Thus, the information from scour monitoring at bridge foundations could be very useful to reduce the bias and improve scour estimation models [50].…”

Multi-Hazard Assessment of Bridges in Case of Hazard Chain: State of Play and Application to Vehicle-Pier Collision Followed by Fire

“…These are depicted in the chord diagram of Figure 4, which suggests that earthquake hazard has been the dominant research issue in a multi-hazard environment (71 cases out of the 108), followed by blast (10) and corrosion (10). Principal hazard chains with earthquake in literature are scour (21) and flooding (19): in the first case (scour), the count includes those cases that focus on scour independently from the cause (Pizarro et al, 2020), while in the latter (flooding), the count includes often flooding-induced scour.…”