Print this page Highway Subdrainage Design
Vincent D. Reynolds, MBA, P.E.
Course Outline
Subdrainage of excessive and uncontrolled subsurface water can carry water away from the pavement or lower the water table to facilitate a new roadway construction. This course will cover the adverse effects of subsurface water, infiltration, subsurface drainage design and maintenance of subdrainage systems.
This 8 hour course will provide the reader with the knowledge to design efficient subgrade drainage systems.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of course materials.
Learning
Objective
At the conclusion of this course, the student would have learned the following:
- The effect of subsurface water on highways;
- How to define capillary moisture;
- The many forms of subsurface water;
- How to use Darcy’s law to determine water flow through soil;
- The main source of water infiltration;
- How to calculate the length of the flow path;
- The best location for longitudinal drains;
- The various ways to determine the coefficient of permeability;
- The various classifications of soils and their typical permeability rates;
- How the water table may be affected by infiltration through pavement;
- How to determine the size of subdrainage pipes;
- How to determine the rate of infiltration;
- How to determine soil porosity;
- How to define slope instability;
- How to determine the value of normal cracking;
- How to define seepage;
- How to determine the influence distance;
- The cause of ice lenses;
- Solutions to repair a pumping pavement system;
- How to determine the degree of drainage;
- When fin drains are an advantage over other subdrainage systems;
- The process to determine the average outflow rate;
- How to determine the filter size for slotted pipes;
- How to determine the average rate of heave;
- The various index properties of soil;
- When the backfill of trenches should occur after placing collector pipes;
- How to determine the slope of the flow path of a pavement structural section;
- How to shorten the flow path of subdrainage systems;
- How excess moisture can have an effect on structural integrity;
- How to determine the degree of permeability of various soil types;
- How to determine the 1 hour/ 1 year frequency rates for the contiguous United States; and
- The sequence of construction for a subdrainage system.
Intended Audience and Benefit
This is intended for highway engineers, geotechnical engineers, hydrologists, designers, project managers, or any persons working in civil engineering field or anyone with an interest in Highway Subdrainage Design and roadway construction.
Course Introduction
Excessive and uncontrolled subsurface water can be detrimental to the structural stability of roadway pavement. Subsurface water can be a result of water infiltrating from the pavement surface or from groundwater. The removal of water from the pavement section and subgrade can be done with the use of subsurface drainage structures that collects the water and drains it away from the pavement cross section.
Course Content
This course will provide the reader with the knowledge to design efficient subgrade drainage systems. The course material is based on the document “Highway Subdrainage Design,” published on the website of the Federal Highway Administration.
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
The information presented in this course provided a detailed overview of the design and maintenance of Highway Subdrainage Design.
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 successfully design safe and efficient Highway Subdrainage systems.
Related Links
For additional technical information related to this subject, please visit the following websites:
http://www.fhwa.dot.gov/
www.aashto.com
www.ite.com
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.
