01643946

Monograph

http://www.trb.org/Main/Blurbs/176359.aspx

The most common cause of bridge failure is scour. Consequently, one of the most important elements of bridge design is the ability to predict the effects of scour so that foundations can be designed to withstand these effects over the life of the bridge. Such predictions require the use of complex hydraulic equations, which are set out in Federal Highway Administration’s (FHWA’s) Hydraulic Engineering Circular No. 18 (HEC-18), the go-to resource for designing bridges to withstand bridge scour. A second circular, HEC-20, addresses channel migration and stream stability. A third, HEC-23, details the design and use of countermeasures to prevent scour and stream instability. After a series of scour-related bridge failures during floods in the 1980s, the Transportation Research Board’s National Cooperative Highway Research Program (NCHRP) embarked on several research projects to better quantify and model the mechanisms of bridge scour and to develop effective, efficient countermeasures to its occurrence. This research led to a wealth of new knowledge about scour, followed by major updates to HEC-23 in 2009 and to HEC-18 and HEC-20 in 2012.The projects described here are selected from that research. Also presented are recent and ongoing efforts that will lead to further improvements of scour estimates—along with updates to FHWA’s circulars—in the coming years. The sections of the report highlight: bank erosion countermeasures, bridge scour countermeasures, predictive equations for scour, and scour special cases.

English

8p

2017-7

NCHRP Research Topic Highlights

Digital/other

Photos

Banks (Waterways); Bridge design; Bridge foundations; Countermeasures; Equations; Erosion; Hydraulic properties; Scour

Bridges and other structures; Design; Highways; Hydraulics and Hydrology

TRIS, TRB, ATRI

Aug 23 2017 1:52PM