# Presentation: 105668

## 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

**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

**CATASTROPHIC FAILURES**
**Schoharie Creek, New York - 1987**
**Hatchie River, Tennessee - 1989**
**I-5 (Los Gatos Creek), California - 1995**

## Slide 5

## Slide 6

## Slide 7

## 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 (K****4****)**
** ****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 

**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**

## 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

**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**

**COUNTERMEASURE DESIGN FOR BRIDGE SCOUR AND STREAM INSTABILITY**
**NHI Course 135048**