FLOOD06847

• County: Statewide
• Basin: Statewide
• Title: Bridge Scour and Stream Instability Countermeasures
• Date: 7/1/1997
• Prepared By: Federal Highway Administration
• Floodplain - Doc Type: Educational/Technical/Reference Information

TABLE OF CONTENTS

1.0 INTRODUCTION.................................................................. ............................................. 1
2.0 PURPOSE AND SOURCES.............................................................................................. 1
3.0 THE COUNTERMEASURES MATRiX.............................................................................. 2

3.1 Overview................................................................................................................ 2
3.2 Countermeasure Groups........................................................................................ 3

3.2.1 Group 1. Hydraulic Countermeasures ..................................................... 3

3.2.1.1 Group 1.A River Training Structures ...................................... 3
3.2.1.2 Group 1.B Armoring Countermeasures ..................................4

3.2.2 Group 2. Structural Countermeasures..................................................... 4
3.2.3 Group 3. Monitoring ................................................................................ 5

3.3 Biological Countermeasures ................................................................................... 6
3.4 Countermeasure Characteristics............................................................................ 6

3.4.1 Functional Applications ............................................................................ 6
3.4.2 Suitable River Environment ..................................................................... 7

3.4.3 Maintenance............................................................................................ 8
3.4.4 Installation/Experience by State Highway Agencies ................................. 8
3.4.5 Design Guideline Reference .................................................................... 8

4.0 COUNTERMEASURE DESIGN PHILOSOPHy................................................................. 8

4.1 Investment in Countermeasures ............................................................................. 8
4.2 Countermeasure Design Approach.........................................................................9
4.3 Environmental Considerations ................ ...............................................................1 0
4.4 Other Design Considerations .................................................................................1 0

4.4.1 Filter Requirements .................................................................................1 0
4.4.2 Edge Treatment ......................................................................................11

5.0 DESIGN GUiDELINES.................................................................................................... ..11

5.1 Overview ...............................................................................................................11
5.2 Countermeasure Design Guidelines ......................................................................12

5.3 Case Histories...................................................................................................... .13

6.0 REFERENCES................................................................................................................. .14

6.1 Matrix References .................................................................................................14
6.2 Supplemental References.................................................................................... .15