Countermeasures to protect bridge from scour

The frequency and extent of bridge damages and collapses, caused by flood and scour processes occurring in correspondence with bridge piers and abutments, have prompted many members of the Italian Hydraulic Group (GII) to set up a working group with the aim of formulating proposals for good practices/ guidelines for assessments of Hydraulic Compatibility of Bridges (GII‐CIP workgroup ‐ sites.google.com/view/gii-ponti), as a basis both for safety assessments of bridges and for flood risk analysis of the surrounding area. Within this group, several working groups have been created, whose objective is the drafting of operational proposals for the various aspects of the problem (danger, vulnerability, risk management, countermeasures to protect bridge, etc.), to be submitted for discussion among all the members of the group, to obtain shared and validated proposals from the Hydraulic Engineering community. Most of the techniques and guidelines that are available for protecting bridge piers and abutments against scour have been developed from small‐scale, hydraulic modelling conducted in laboratories, and a limited amount of empirical data along with anecdotal observations has been acquired from field sites. In this context, the aim of the paper is to develop and recommend a few technical selection criteria for bridge scour countermeasures, and guidelines for design and construction