Rankine Earth Pressures
Rankine Earth Pressures
(OP)
Does anyone have a reference for reducing active/at-rest pressures for a retaining wall for a soil that slopes downward behind the wall? My texts only have equations for when the slope on the retaining side goes upward.
Thanks!
Thanks!





RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
Many geotech books also have graphs or tables for these coefficients with respect to slope angles.
As mentioned above, the angles for the equations need to be less than the phi angle of the soil.
You should check out various geotech books or call your geotech consultant.
www.PeirceEngineering.com
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
BigH - Thanks a lot - I think I may have a pdf of Bowles somewhere. I can at least see how the negative beta was derived so I can rationalize a reduction for more than 10 deg (mine is about 25).
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
http://nptel.ac.in/courses/105101083/download/lec7...
www.PeirceEngineering.com
RE: Rankine Earth Pressures
This statement competes with the Coduto and Bowles texts I have. Both texts use Rankine as one of many methods for determining horizontal pressures on retaining walls.
RE: Rankine Earth Pressures
(You can derive Rankine yourself very easily, beginning with a Mohr circle touching the MC envelope, as if the soil is in a state of failure. Assume sigma-1 is vertical and sigma-3 is horizontal, and solve for sigma-3 as a fn. of sigma-1 and phi'. There is of course no shear stress on the planes of principal stress. Reverse -1 and -3 for passive pressure. If you have more patience than I do, you can derive Coulomb for any beta, negative or positive, by a sliding block.)
RE: Rankine Earth Pressures
RE: Rankine Earth Pressures
I am not sure. Good question - you are probably correct.
BigH - no worries, as that is what I have decided to go with.
Thanks