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WORKSHOP ON PLAN OF ACTION FOR SCOUR CRITICAL BRIDGES. Transportation Research Board 2002 Annual Meeting Sponsored By A2A03 Committee on Hydrology, Hydraulics and Water Quality. SESSIONS 582 AND 610 J. Sterling Jones – FHWA Peter F. Lagasse – Ayres Associates Jorge E. Pagan-Ortiz – FHWA
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WORKSHOP ON PLAN OF ACTION FOR SCOUR CRITICAL BRIDGES Transportation Research Board 2002 Annual Meeting Sponsored By A2A03 Committee on Hydrology, Hydraulics and Water Quality
SESSIONS 582 AND 610 • J. Sterling Jones – FHWA • Peter F. Lagasse – Ayres Associates • Jorge E. Pagan-Ortiz – FHWA • David R. Pearson – GKY & Associates
OVERVIEW AND UPDATES TO HEC 18, 20, AND 23 P.F. Lagasse, Ph.D., P.E. Transportation Research Board 2002 Annual Meeting Sponsored By A2A03 Committee on Hydrology, Hydraulics and Water Quality
BRIDGE SCOUR CATASTROPHIC FAILURES • Schoharie Creek, New York - 1987 • Hatchie River, Tennessee - 1989 • I-5 (Los Gatos Creek), California - 1995
BRIDGE SCOUR A WIDESPREAD PROBLEM • 481,251 Bridges over Water • 25,858 Scour Critical • 88,686 Unknown Foundations
A DECADE OF RESEARCH EDUCATION AND TRAINING • HEC-18 Bridge Scour • HEC-20 Stream Stability • HEC-23 Countermeasures • ASCE Compendium on Bridge Scour • 1998 European Scanning Review • 1999 New Zealand Scanning Review
COMPREHENSIVE METHODOLOGY HEC-20 HEC-18 HEC-23
HEC-18 REVISIONS (FOURTH EDITION) • Reorganize by Topic • Move Countermeasure Design to HEC-23 • Pier Scour in Coarse Material (K4) • Scour for Complex Pier Foundations • Pressure Flow Scour • Alternative Approaches for Abutment Scour • Special Considerations • - Plan of Action • - Item 113 Coding Revisions • - Scour in Cohesive Soils • - Scour in Rock
HEC-20 REVISIONS (THIRD EDITION) • Move Countermeasure Selection and Design to HEC-23 • Stream Reconnaissance, Classification, and Response • Rapid Assessment Method • Quantitative Analysis Techniques • - Lateral Stability (Meander) • - Vertical Stability (Degradation) • - Sediment Continuity • Channel Restoration Concepts • Geotechnical Considerations for Bank Stability
HEC-23 REVISIONS (SECOND EDITION) • Becomes the Primary Reference for Countermeasure Design • Strategies for Plan of Action • Hydraulic Analysis - Physical Modeling • - Scour at Transverse Structures • - Scour at Longitudinal Structures • Special Considerations for Riprap and Filter Design
HEC-23 REVISIONS (SECOND EDITION) • Biotechnical Engineering • Guidance from Outside U.S. • Instrumentation and Monitoring • Additional Design Guidelines - Design Procedure for Grout Filled Mattresses - Modular Design for Concrete Armor Units - Revetment Guidelines from HEC-11
TRAINING COURSE REVISIONS • Stream Stability and Scour (HEC-18 & 20) • Countermeasure Design (HEC-23 and DP 97) • Update 1-Day Bridge Inspectors Course • Develop Course Materials for HDS6
HDS 6 REVISIONS • Update Technology from 1970s to 1990s • Expanded Sediment Transport Chapter - Comprehensive Comparison of Formulas - Formula Selection based on Transport Mode - New Sediment Transport Relationships • More Channel Response Case Studies • Better Integration with HEC-18, -20, & -23 • To Be Issued as HDS-6
HDS 6 • River Engineering for Highway Encroachments – Highways in the River Environment • REHIRE
STREAM STABILITY AND SCOUR AT HIGHWAY BRIDGES NHI COURSE 135046 Overall Course Learning Objectives 1. Identify stream instability and scour problems at bridges 2. Conduct a stream stability reconnaissance 3. Classify the stream, identify potential problems, and conduct a qualitative analysis of response 4. Calculate long-term degradation quantities
STREAM STABILITY AND SCOUR AT HIGHWAY BRIDGES NHI Course 135046 5. Calculate general and local scour at bridge piers and abutments for simple and complex substructures 6. Plot and evaluate the total scour prism 7. Define and compare channel restoration and channel rehabilitation concepts 8. Draft a Plan of Action for correcting stream instability and scour problems
COUNTERMEASURE DESIGN FOR BRIDGE SCOUR AND STREAM INSTABILITY NHI Course 135048 Overall Course Learning Objectives 1. Prepare a Plan of Action for correcting stream instability and scour problems considering a range of countermeasure options and strategies 2. Select appropriate countermeasures considering functional applications and river characteristics 3. Estimate scour at longitudinal and transverse structures
COUNTERMEASURE DESIGN FOR BRIDGE SCOUR AND STREAM INSTABILITY NHI Course 135048 Overall Course Learning Objectives 4. Describe the advantages and disadvantages of biotechnical engineering 5. Describe a range of alternatives to conventional riprap and filter techniques for local scour protection 6. Design channel instability and bridge scour countermeasures for specific stream instability or scour problems
COUNTERMEASURE DESIGN FOR BRIDGE SCOUR AND STREAM INSTABILITY NHI Course 135048 Overall Course Learning Objectives 7. Describe other countermeasures for stream instability and scour and evaluate their performance 8. Given a scour critical bridge, select and design a monitoring program to reduce the risk from scour 9. Integrate portable and fixed instruments into a monitoring program