PROGRESS REPORT OF MODEL STUDIES OF SCOUR AROUND BRIDGE PIERS AND ABUTMENTS
UNDER THE SPONSORSHIP OF THE IOWA STATE HIGHWAY COMMISSION AND THE BUREAU OF PUBLIC ROADS, THE IOWA INSTITUTE OF HYDRAULIC RESEARCH UNDERTOOK A COMPREHENSIVE EXPERIMENTAL INVESTIGATION OF THE BRIDGE-SCOUR PROBLEM. THE PROGRAM WAS DIVIDED INTO FOUR PHASES: (1) GEOMETRY OF PIERS AND ABUTMENTS; (2) HYDRAULIC CHARACTERISTICS OF THE STREAM, PRIMARILY THE VELOCITY AND DEPTH OF FLOW; (3) SEDIMENT CHARACTERISTICS; (4) GEOMETRY OF CHANNEL CROSS SECTION AND ALIGNMENT. A SERIES OF TESTS OF THE COMPARATIVE DEPTH OF SCOUR FOR REPRESENTATIVE IOWA PIER AND ABUTMENT DESIGNS HAS BEEN COMPLETED AS PART OF THE FIRST PHASE OF THE PROJECT. THE MOST SIGNIFICANT ASPECT OF THE PIER GEOMETRY WAS FOUND TO BE THE ALIGNMENT RELATIVE TO THE CURRENT OF ALL WEBBED DESIGNS. COMPARED TO THIS EFFECT THE SHAPE OF THE PIER SHAFT ITSELF WAS OF SECONDARY IMPORTANCE. SINCE ABUTMENT SHAPES DIFFER MORE THAN PIER SHAPES DO, A SOMEWHAT LARGER EFFECT COULD BE ASCRIBED TO THEIR DETAILED GEOMETRY. HOWEVER, POSSIBLY THE MOST IMPORTANT INFORMATION OBTAINED HAS BEEN THE FACT THAT THE SCOUR HOLE AT DEBRIS-FREE ABUTMENTS IS INVARIABLY DEEPEST AT THE UPSTREAM ABUTMENT CORNER. THIS INFORMATION HAS AN IMMEDIATE APPLICATION TO DESIGN PRACTICE, ESPECIALLY IN THE CASE OF A STUB ABUTMENT WITH SHEET PILING ENCLOSING THE EARTH FILL. PIER GEOMETRY WAS USED IN THE DEVELOPMENT OF SHAPES WHICH WILL RESULT IN MINIMUM SCOUR. THE EFFECT OF THE VELOCITY AND DEPTH OF FLOW ON THE SCOUR DEPTH WAS ALSO INVESTIGATED. SINCE THE RATE OF SEDIMENT TRANSPORTATION IS ALSO DEPENDENT ON THE HYDRAULIC CHARACTERISTICS OF THE STREAM, A SPECIAL FLUME INCORPORATING A SAND-FEED MECHANISM AND A SAND-TRAP BALANCE WAS CONSTRUCTED FOR THIS STUDY. /AUTHOR/
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Supplemental Notes:
- Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
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Corporate Authors:
Highway Research Board (HRB)
Washington, DC -
Authors:
- Laursen, Emmett M
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Conference:
- 30th Annual Conference of the Highway Research Board
- Location: Washington District of Columbia, United States
- Date: 1951-1-0 to 1951-1-0
- Publication Date: 1951-4
Media Info
- Media Type: Digital/other
- Features: Figures;
- Pagination: 11p
- Monograph Title: Scour around bridges
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Serial:
- Highway Research Board Research Reports
- Issue Number: 13B
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Bridge abutments; Bridge design; Bridge piers; Bridges; Hydraulic structures; Scour; Structural design
- Uncontrolled Terms: Hydraulic models; Model tests
- Subject Areas: Bridges and other structures; Highways; Hydraulics and Hydrology;
Filing Info
- Accession Number: 00204417
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: May 22 1972 12:00AM