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Guidelines for Bridges Over Degrading and Migrating Streams, Part 1: Synthesis of Existing Knowledge

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Guidelines for Bridges Over Degrading and Migrating Streams, Part 1: Synthesis of Existing Knowledge Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. TX-01/2105-2 4. Title and Subtitle 5. Report Date GUIDELINES FOR BRIDGES OVER DEGRADING AND January 2001 MIGRATING STREAMS. PART 1: SYNTHESIS OF EXISTING 6. Performing Organization Code KNOWLEDGE 7. Author(s) 8. Performing Organization Report No. Jean-Louis Briaud, Hamn-Ching Chen, Billy Edge, Siyoung Park, and Report 2105-2 Adil Shah 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Texas Transportation Institute The Texas A&M University System 11. Contract or Grant No. College Station, Texas 77843-3135 Project No. 7-2105 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Texas Department of Transportation Research: Construction Division Sept. 1999 – Aug. 2000 Research and Technology Transfer Section 14. Sponsoring Agency Code P. O. Box 5080 Austin Texas 78763-5080 15. Supplementary Notes Research performed in cooperation with the Texas Department of Transportation. Research Project Title: Develop Guidance for Design of New Bridges and Mitigation of Existing Sites in Severely Degrading and Migrating Streams 16. Abstract This report is a collection of existing knowledge on the following topics: prediction of meander migration rate and stream bed degradation rate, and countermeasures for mitigating meander migration and stream bed degradation. Based on existing knowledge, two main conclusions were reached on the prediction of meander migration and stream bed degradation: 1. There is no reliable formula to predict these erosion movements. 2. The best existing way to predict such erosion movements is by extrapolation of historical data. Based also on existing knowledge, three main conclusions were drawn on the countermeasures for mitigating meander migration and stream bed degradation: 1. There are a large number of countermeasures to choose from. 2. There is no scientific basis for choosing the right countermeasure for a given case. 3. The best current practice is based on local experience and trial and error approach. 17. Key Words 18. Distribution Statement Meander Migration, Stream Bed Degradation, Bank No Restrictions. This document is available to the Erosion, Rate of Movement Prediction, public through NTIS: Countermeasures National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161 19. Security Classif.(of this report) 20. Security Classif.(of this page) 21. No. of Pages 22. Price Unclassified Unclassified 194 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized GUIDELINES FOR BRIDGES OVER DEGRADING AND MIGRATING STREAMS. PART 1: SYNTHESIS OF EXISTING KNOWLEDGE by Jean-Louis Briaud Research Engineer Texas Transportation Institute Hamn-Ching Chen Associate Professor Texas A&M University Billy Edge Professor Texas A&M University Siyoung Park and Adil Shah Graduate Students Texas A&M University Report 2105-2 Project Number 0-2105 Research Project Title: Develop Guidance for Design of New Bridges and Mitigation of Existing Sites in Severely Degrading and Migrating Streams Sponsored by the Texas Department of Transportation January 2001 TEXAS TRANSPORTATION INSTITUTE The Texas A&M University System College Station, Texas 77843-3135 DISCLAIMER The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views of policies of the Texas Department of Transportation (TxDOT). This report does not constitute a standard, specification, or regulation. In addition, the above assumes no liability for its contents or use thereof. The engineer in charge of the project was Dr. Jean-Louis Briaud, P.E. # 48690. v ACKNOWLEDGMENTS This project was sponsored by the Texas Department of Transportation. The project director and chairman of the Project Monitoring Committee was Tom Dahl, who struck a very appreciated balance between listening to the researchers’ concerns and maintaining the best interest of TxDOT. Mr. Dahl took a very active part in the research process and visited several of the case history sites. It was a pleasure to work with him. The program coordinator was Tony Schneider whose vision over the last six years has helped put TxDOT at the forefront of scour knowledge. He is succeeded by David Stolpa who has already helped the research team on several occasions. The RMC 3 staff engineer in the Construction Division Research, Technology, and Transfer Section was William Knowles. The Project Monitoring Committee was composed of Rocky Armendariz, Robert Balfour, Kathy Dyer, Elston Eckhardt, Gerald Freytag, Donald Harley, Mark McClelland, and Wendy Worthey. We appreciate their support and their constructive criticisms. We also wish to extend special thanks to the TxDOT engineers who guided our five site visits: Kathy Dyer and Scott Shannon for the visit in the Paris District, Jerry Freytag for the visit in the Yokum district, Pat Williams and Terry Paholek of the Bryan District, John Kilgore of the San Antonio District, and Robert Balfour of the Beaumont District. vi TABLE OF CONTENTS LIST OF FIGURES ..................................................................................................................... xiii LIST OF TABLES..................................................................................................................... xviii 1. INTRODUCTION .......................................................................................................................1 1.1 What?...........................................................................................................................1 1.2 Why?............................................................................................................................1 1.3 How?............................................................................................................................1 1.4 Where, When, by Whom, and for Whom? ..................................................................1 1.5 Organization of the Report ..........................................................................................2 2. RIVER PATTERNS AND STABILITY.....................................................................................3 2.1 Channel Classification ................................................................................................3 2.2 Lane Relation..............................................................................................................7 2.3 River Metamorphosis..................................................................................................8 3. MEANDER MIGRATION........................................................................................................11 3.1 Bank Erosion............................................................................................................11 3.2 Meander Growth and Shift ......................................................................................11 3.3 Cutoffs .....................................................................................................................12 3.4 Avulsion...................................................................................................................13 4. DEGRADATION AND AGGRADATION .............................................................................15 4.1 Aggradation ..............................................................................................................15 4.2 Backfilling and Downfilling .....................................................................................15 4.3 Nickpoint Migration .................................................................................................16 4.4 Degradation and Scour..............................................................................................16 5. RAPID CHANNEL STABILITY ASSESSMENT METHOD.................................................19 5.1 Stream Reconnaissance and Field Inspection...........................................................19 5.2 Remote Sensing Techniques (Aerial Photographs) ..................................................19 6. PREDICTION OF MEANDER MIGRATION………………………………………………. 21 6.1 Begin, Z.B., 1981, “Stream Curvature and Bank Erosion: A Model Based on the Momentum Equation.”....................................................................................21 6.2 Begin, A.B., 1986, “Curvature Ration and Ratio of River Bend Migration Update.” .....................................................................................................................21 6.3 Brice, J. C., 1982, “Stream Channel Stability Assessment.”.....................................24 6.4 Chang, H. H., 1984, “Analysis of River Meanders.”.................................................26 6.5 Chang, T. P., Toebes, G. H., 1980, “Geometric Parameters for Alluvial Rivers Related to Regional Geology.”......................................................................27 6.6 Chitale, S. V., 1980, “Shape and Mobility of River Meanders.”...............................28 6.7 Comes, B. M., 1990, “Identification Techniques for Bank Erosion and Failure Processes.”....................................................................................................29 vii TABLE OF CONTENTS (continued) 6.8 Diehl, T. H., and Bryan, B. A., 1993, “Supply of Large Woody Debris in a Stream Channel.”......................................................................................................30
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