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.

This paper analyzes the properties of the dynamic behavior of two adjacent buildings of different height connected by viscous/viscoelastic dampers located at the top of the shortest building. The adjacent structures are described through a continuum approach as two interconnected uniform shear beams. This permits to identify the set of characteristic parameters describing the building and damper properties that completely control the dynamic behavior of the system. An analytical solution is derived for solving the eigenvalue problem via complex modal analysis, and a parametric study is carried out to evaluate the influence of these characteristic parameters on the properties of the dynamic system. A reduced-order model of the system is also developed, and simplified formulas are obtained for estimating the damping ratios of the first two modes of the coupled system. Two case studies consisting of realistic shear-type adjacent buildings coupled by viscous dampers are finally analyzed. The estimates of the modal properties obtained by using the proposed analytical approach and a finite element formulation are compared with each other. It is shown that the proposed approach provides information useful for the preliminary design of the damper properties ensuring the optimal control against seismic loadings. Copyright © 2015 John Wiley & Sons, Ltd.

Bridges are critical-infrastructure components of road and rail transport networks. A large number of these critical assets cross or are adjacent to waterways and floodplains and are therefore exposed to flood actions such as scour, hydrodynamic loading, and inundation, all of which are exacerbated by debris accumulations. These stressors are widely recognized as responsible for the vast majority of bridge failures around the world, and they are expected to be exacerbated due to climate change. While efforts have been made to increase the robustness of bridges to the flood hazard, many scientific and technical gaps remain. These gaps were explored during an expert workshop that took place in April 2021 with the participation of academics, consultants, and decision makers operating mainly in the United Kingdom and specializing in the fields of bridge risk assessment and management and flood resilience. The objective of the workshop was to identify and prioritize the most urgent and significant impediments to bridge flood resilience. In particular, the following issues, established at different levels and scales of bridge flood resilience, were identified and analysed in depth: (i) characterization of the effects of floods on different bridge typologies, (ii) uncertainties in formulae for scour depth assessment, (iii) evaluation of consequences of damage, (iv) recovery process after flood damage, (v) decision-making under uncertainty for flood-critical bridges, and (vi) use of event forecasting and monitoring data for increasing the reliability of bridge flood risk estimations. These issues are discussed in this paper to inform other researchers and stakeholders worldwide, guide the directions of future research in the field, and influence policies for risk mitigation and rapid response to flood warnings, ultimately increasing bridge resilience.