Print this page Subsurface Drainage
Vincent D. Reynolds, MBA, P.E.
Course Outline
This 5 hour course will cover the design of subsurface drainage that is used to drain water away from the subgrade into a channel or piping system. Subsurface drainage is useful for rigid and flexible paved surface such as highways, streets, parking lots, runways and other paved areas. A vast amount of information will be presented such as understanding the flow of water through soils, uses of various filters, constructing the drainage layer, and much more. Design examples will also be presented to aid in understanding the course material.
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 would have learned the following:
- Causes of surface water into pavement;
- The roughness of various pipes;
- The permeability of various soils;
- How to determine the effective porosity of soils;
- How to determine the design storm index;
- How to determine soil frost group;
- How to determine the porosity;
- The most suitable design storm to design subsurface drainage;
- How to determine the length of a drainage path in a subsurface drainage system;
- Types of collector pipes for edge subdrains;
- How to determine the 85 percent time to drain;
- How to determine the most suitable storm separation layer;
- How to determine the minimum permeability for most drainage layers;
- How to determine the uniformity coefficient (Cv);
- How compaction material should be treated on-site;
- How to determine the flow-rate of water through circular pipes;
- Various criteria for placing collector drains including trench construction;
- The most suitable placement locations for lateral outlet pipes and manholes on subgrade pipe drains;
- How to determine the time for 50 percent drainage; and
- The required permeability rates of open graded material.
Intended Audience
This course is intended for anyone with an interest in subsurface drainage, hydraulics, pavement design, roadway design, water resources, city planning, or anyone wanting to learn about subsurface drainage.
Benefit to Attendees
This course is designed so that the intended audience will benefit immediately with the information to aid in the effective design of subsurface drainage.
Course Introduction
Water from rainfall can have deleterious effects on the earth’s surface causing erosion and producing sediment. The underlying earth or subsurface of paved roads, runways, and parking lots are protected from rainfall via rigid or flexible surfaces such as asphalt or concrete. However if deteriorated surfaces exist, water can travel to the subbase or subsurface and saturate those surfaces. A subsurface that has been inundated with water is one the main causes of pavement failure. Water caught between a subsurface and flexible or rigid pavement can erode the underlying soil creating voids thus causing the pavement surface to lose some of its structural support.
Course Content
This course will cover the design of subsurface drainage that is used to drain water away from the subgrade into a channel or piping system. Subsurface drainage is useful for rigid and flexible paved surface such as highways, streets, parking lots, runways and other paved areas. A vast amount of information will be presented such as understanding the flow of water through soils, uses of various filters, constructing the drainage layer, and much more. Design examples will also be presented to aid in understanding the course material.
You will be directed to study the document “Subsurface Drainage,” published by the army corps of engineers which also serves as a document for the Unified Facilities Criteria (UFC).
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
This course is designed so that the intended audience will benefit immediately with the information presented.
Using good engineering judgment is always paramount in any situation. Utilizing good judgment and the knowledge gained in this course will aid the reader with the knowledge to design efficient subsurface drainage systems.
Related Links
For additional technical information related to this subject, please visit the following websites:
Federal Highway Administration:
http://www.fhwa.dot.gov/
Unified Facilities Criteria:
http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4
Environmental Protection Agency (EPA):
http://www.epa.gov/
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
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.
