Stable Channel Analysis and Design

Joseph V. Bellini, PE, PH, DWRE, CFM

Course Outline

One of the more significant issues affecting the quality and integrity of stream systems are instability and sediment loading. While much of the suspended sediment load are small particles (clay and silt) from watershed yield, larger bed-material particles are being eroded, transported, and deposited within stream channels. This course is intended to provide techniques to evaluate erosion potential and design measures to stabilize streams and channels.

This course discusses the following topics:

• Estimating Channel Velocity

• Estimating Average Channel Velocity
• Manning’s Roughness (n) Estimates
• Using HEC-RAS to Estimate Velocity Distribution through Conveyance Tubes
• Depth-Averaged Velocity in a 2D Model

• Evaluating Erosiveness based on Velocity Method

• Non-Cohesive Soil
• Cohesive Soil
• Vegetation

• Evaluating Erosiveness based on Maximum Tractive Force/Shear Method

• Shear Stress in Fluids
• Estimating Average Bottom Shear
• Applied Shear on Curved Channels
• Critical Shear for Non-Cohesive Soils
• Critical Shear for Cohesive Soils
• Critical Shear for Vegetation and Riprap
• FHWA HEC-15 Software (developed by North American Green)

• Geometric Design of Channels

• USBR Stable Channel Dimensions
• Freeboard
• Ideal Channel Section Geometry
• Stable Channel Slope

• Slope Revetment Design

• Riprap
• Gabions
• Grouted Rock
• Articulated Concrete Block

• HEC-RAS Stable Channel Design Tool

• Copeland Method
• Regime Method
• Tractive Force Method

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will learn:

• How to estimate Manning’s Roughness (n) value for various types of channel lining;
• How to estimate average channel velocity;
• How to compute lateral velocity distribution using HEC-RAS;
• How to assess channel stability using maximum velocity methods;
• How to estimate average shear stresses/tractive forces in channels;
• How to estimate shear stresses/tractive forces along side slopes and channel bends;
• How to assess channel stability using maximum shear/tractive force methods;
• Guidelines for cross-sectional geometry of a stable channel;
• Method for computing ‘limiting’ channel slope;
• Standards and procedures for designing riprap, gabion, grouted rock, and articulated concrete block slope revetment;
• Method for assessing stability of articulated concrete block in a hydraulic jump; and
• Use HEC-RAS to evaluate channel stability.

Intended Audience

This course is intended for civil and water resources engineers, hydrologists, environmental scientists, and watershed planners.

Benefit to Attendees

Attendee of this course will be exposed to a comprehensive set of techniques to evaluate and design for channel stability.

Course Introduction

One of the more significant issues affecting the quality and integrity of stream systems are instability and sediment loading. While much of the suspended sediment load are small particles (clay and silt) from watershed yield, larger bed-material particles are being eroded, transported, and deposited within stream channels. This course is intended to provide techniques to evaluate erosion potential and design measures to stabilize streams and channels.

Course Content

This course is in the following PDF document:

Stable Channel Analysis and Design

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

One of the more significant issues affecting the quality and integrity of stream systems are instability and sediment loading. While much of the suspended sediment load are small particles (clay and silt) from watershed yield, larger bed-material particles are being eroded, transported, and deposited within stream channels. This course is intended to provide techniques to evaluate erosion potential and design measures to stabilize streams and channels.

Related Links

For additional technical information related to this subject, please visit the following websites or web pages:

FHWA Hydraulic Engineering Publications: http://www.fhwa.dot.gov/engineering/hydraulics/
North American Green Stable Channel Design Software: http://www.nagreen.com/

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

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DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.

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