Career Development and Resources for Geotechnical Engineers

External Friction Angle

External Friction

Home         Forum         Publications         Software         Career Development         About         Contact         Donate

Geotechnical Info Search

Geotechnical Forum
Ask for technical help or discuss geotechnical issues with other engineers

Geotechnical Publications
Free publications and resources for geotechnical engineers

Geotechnical Software
Download free software and links to geotechnical software

Technical Guidance
Valuable technical information for geotechnical engineers. Your questions may be answered here.

Learning Center
Learning and training resources for geotechnical engineers.

Career Development
Tips for earning more respect and more money. Market yourself.

External Friction Angle

The external friction angle, d, or friction between a soil medium and a material such as the composition from a retaining wall or pile may be expressed in degrees as the following:



20 degrees for steel piles (NAVFAC)

0.67f - 0.83f (USACE)

20 degrees for steel (Broms)
f3/4 for concrete (Broms)
f2/3 for timber (Broms)

0.67f (Lindeburg)

Nordlund attempts to more precisely quantify the external friction angle, d, by using various charts based on the angle of internal friction, f, and volume of pile

               where f = angle of internal friction of the soil (degrees)


Retaining Walls

d = 2f         for concrete walls (Coulomb)

               where f = angle of internal friction of the soil (degrees)


Other soil and soil related properties are listed below:

Angle of Internal Friction
Bearing Capacity Factors
External Friction Angle
Factor of Safety
Lateral Earth Pressure Coefficients
Modulus of Vertical Subgrade Reaction
Soil Unit Weights
Young's Modulus or modulus of elasticity


You are encouraged to provide any additional information or evaluation concerning the content of Geotechnical Info .Com. Comments can be sent here.

Tell a friend! about Geotechnical Info .Com

Technical Resources

Other Geotechnical Links

Other Geotechnical Resources


     Donate             Advertise             Contact             Privacy Statement             Legal Notice

© Copyright 2007-2012 by All rights reserved.