FHWA Bridge Scour Workshop
- Bridge Scour Workshop Presentations
- Session 1 of 4 (Introductions, FHWA Bridge Program Update, Bridge Scour Overview)
- Session 2 of 4 (Long Term Degradation, Contraction Scour)
- Session 3 of 4 (Pier Scour and Abutment Scour)
- Session 4 of 4 (Comprehensive Bridge Scour Example with 2D Bridge Scour Tools and Wrap Up)
Overview
Understanding how to correctly evaluate bridge scour is paramount to designing foundations that are safe and resilient throughout the service life of a bridge. Unfortunately, many design engineers who are responsibility for providing bridge scour estimates to support foundation design, often charge through the process of hydraulic modeling and scour computation without a thorough understanding of the concepts and methodology. Through reviews of sample bridge projects from several states, the FHWA Resource Center has noted a concerning number of cases in which the scour estimates were erroneous, resulting from a range of factors, including; unsuitable hydraulic modeling, improper extraction of hydraulic parameters for scour analysis, or incorrect application of the HEC-18 scour equations and methodology.
This workshop will address these concerns and is intended to be a 'refresher' course on scour, for those who have taken the NHI training course on stream stability and scour (#135046), and an overview of bridge scour analyses for those who are new to performing scour analyses.
Participants of this workshop will learn best practices for extracting hydraulic variables to compute scour and efficiently apply the results. They will also learn about new tools for computing bridge scour with 2D hydraulic models that provide more accurate results. After completing this workshop participants will have a better understanding of the scour evaluation process and an improved confidence in their total scour estimates.
Agenda – Day 1
10:00 – 11:00 Introductions and Opening Questions
- Instructor Introductions
- FHWA Bridge Scour Engineer Program Update
- Workshop objectives
- Recommended resources and training
- The importance of review
- Common pitfalls in computing scour
11:00 – 12:00 Bridge Scour Overview
- Overview of total scour and scour components
- Worst case scour concept
- Geotechnical considerations (non-cohesive, cohesive, rock)
- Importance of good hydraulic modeling
- Extracting hydraulic variables from a hydraulic model for computing scour
- Resources and Tools available for computing bridge scour
12:00 – 1:00 Lunch Break
1:00 – 2:00 Long Term Degradation (LTD) and Stream Stability
- Overview
- Assessment levels and procedures
- Factors that affect LTD and Stream Stability
- Summary of key points for evaluating LTD
- Workshop example for computing LTD
2:00 – 3:30 Contraction Scour
- What is contraction scour?
- Types of scour – Concepts of Live-Bed and Clear Water Scour
- Critical velocity / critical velocity index
- Steps to compute contraction scour
- Extracting hydraulic results
- Summary of key points for evaluating contraction scour
- Workshop example for computing contraction scour
Agenda – Day 2
10:00 – 11:00 Pier Scour
- What causes pier scour?
- Factors that affect pier scour
- Complex pier scour
- Extracting hydraulic results for computing pier scour
- Summary of key points for evaluating pier scour
- Workshop example for computing pier scour
11:00 – 12:00 Abutment Scour
- What is abutment scour?
- FHWA's recommendation of the NCHRP Approach
- Scour Condition A vs. Scour Condition B
- Amplification factors and abutment configuration
- Extracting hydraulic results
- Summary of key points for evaluating abutment scour
- Workshop example for computing abutment scour
12:00 – 1:00 Lunch Break
1:00 – 2:30 Bridge scour comprehensive example (using 2D hydraulic modeling)
- Review of hydraulic modeling results
- Extracting hydraulic parameters for bridge scour analysis
- Computation of bridge scour components
- SMS Bridge Scour Tool and new multi-profile capability, basic functionality
- Hydraulic Toolbox bridge scour calculator
- Total scour summary and plots
2:30 – 3:00 Wrap-Up and Questions
- Recap key points in computing scour