Print Email Facebook Twitter Evaluating Scour at Bridges - Fifth Edition Title Evaluating Scour at Bridges - Fifth Edition Author Arneson, L.A. Zevenbergen, L.W. Lagasse, P.F. Clopper, P.E. Contributor Krolak, J. Kerenyi, K. Anderson, S. Henderson, D. Bergendahl, B. Mohamed, K. Corporate name Ayres Associates Project HEC Date 2012-04 Abstract This document is the fifth edition of HEC-18. It presents the state of knowledge and practice for the design, evaluation and inspection of bridges for scour. There are two companion documents, HEC-20 entitled "Stream Stability at Highway Structures", and HEC-23 entitled "Bridge Scour and Stream Instability Countermeasures". These three documents contain updated material from previous editions and continued research by NCHRP, FHWA, State DOTs, and universities. This fifth edition of HEC-18 also contains revisions obtained from further scour-related developments and the use of the 2001 edition by the highway community. The major changes in the fifth edition of HEC-18 are: expanded discussion on the policy and regulatory basis for the FHWA Scour Program, including risk-based approaches for evaluations, developing Plans of Action (POAs) for scour critical bridges, and expanded discussion on countermeasure design philosophy (new vs. existing bridges). This fifth edition includes: a new section on contraction scour in cohesive materials, an updated abutment scour section, alternative abutment design approaches, alternative procedures for estimating pier scour, and new guidance on pier scour with debris loading. There is a new chapter on soils, rock and geotechnical considerations related to scour. Additional changes include: a new approach for pier scour in coarse material, new sections on pier scour in cohesive materials and pier scour in erodible rock, revised guidance for vertical contraction scour (pressure flow) conditions, guidance for predicting scour at bottomless culverts, deletion of the "General Scour" term, and revised discussion on scour at tidal bridges to reflect material now covered in HEC-25 (2nd Edition). Subject scour in cohesive materialscourPier scourbridge inspectionlocal scourscour countermeasuresscour protection Classification TLE6000TLE550350 To reference this document use: http://resolver.tudelft.nl/uuid:0a440453-2125-4f6a-a85c-457c05b82319 Publisher Federal Highway Administration (FHWA) Part of collection Hydraulic Engineering Reports Document type report Rights (c) U.S. Department of Transportation Files PDF HEC-18 scour at bridges.pdf 6.7 MB Close viewer /islandora/object/uuid:0a440453-2125-4f6a-a85c-457c05b82319/datastream/OBJ/view