Course Description:
Erosion of soil due to moving water is a continual challenge for landowners and hydraulic engineers. The most common material used to protect stream channels and banks from erosion is rock riprap. This material is widely available and comparatively inexpensive. Used properly it can provide very good protection against the erosive forces. However, used improperly it can be expensive and/or ineffective. This course will present information that can be used to provide proper sizing, specifications and details so that the design achieves the desired protection.
Course Outline:
• DEFINING THE PROBLEM
o Loss of soil due to erosion
o Forces that create movement
o Forces that resist movement
• RIPRAP SELECTION
o Dimensions and D50
o Gradation
o Materials
o Filter under Riprap
o Placing Geotextiles under Water
o Installation
o Failure Modes
• REQUIRED SIZE OF RIPRAP
o Riprap on Slopes
o Riprap at the end of Pipes
• PROTECTING BANKS
• PROTECTING BRIDGE PIERS
• PROTECTING CHANNELS
• CULVERT EXIT PROTECTION
Learning Objectives:
At the conclusion of this course, the user will:
• Understand the forces that cause loss of soil due to erosion and the forces that resist soil movement.
• Understand the importance of gradation and high-quality materials in selection of riprap sources.
• Understand the importance of filters and geotextiles under riprap.
• Understand how to determine the appropriate size for riprap places on banks and at the end of culverts.
• Understand how riprap is used to protect banks, channels and bridge piers.
Prerequisites:
There are no special prerequisites.
Intended Audience:
This course is intended as an introduction to erosion control using riprap and therefore the intended audience includes engineers designing measures to reduce erosion along stream banks, at bridge abutments and piers and at the end of culverts. It also includes government officials responsible for review of erosion control plans.
Course Summary:
This course will provide the user with a basic understanding of the forces that cause soil erosion in stream channels and along stream embankments. Failure to adequately protect soils from these erosive forces can result in scour, bank erosion and loss of infrastructure, such as bridges and culverts. The course will also provide the user with a basic understanding of how riprap resists these forces. The course will discuss the types of materials that are suitable for use as riprap and address some commonly used materials that are not suitable. It will include the equations and examples necessary to properly size riprap on embankments and at the end of culverts. An understanding of these design parameters allows engineers and managers to make appropriate decisions which will limit the potential for erosion.
