Passive pressures for sloped soil backing

[alwayslearning123]

Hello all.

Does anyone have a good reference, can send me to a thread, or can explain to me how to to determine the passive resistance of a sloped berm? Thank you.

 

[fattdad]

There's a graph in DM-7.1 or 7.2.

f-d

¡papá gordo ain’t no madre flaca!

 

[alwayslearning123]

I think I have found the graph you are talking about (not certain if i can name exact pages on here). However, the graph I found does not help if the berm steps out a couple of feet from the wall before it starts to slope. The graph i found gives Kp values using culombs method. was that the one you were referencing?

Does this work the same way as a passive wedge?

Thank you

 

[dcarr82775]

The passive failure plane is 45+friction angle/2. Take that angle, and figure the weight of soil 'inside' the failure plane. Then do a little right triangle force analysis similar to a trial wedge and you can get the passive resistance. That is what I do anyway.

 

[BigH]

Do a Culmann Graphical Analysis! See Terzaghi Peck and Mesri, page 256 - shows a graphical method (using log-spiral). You would use your "geometry" and carry out.

 

[BigH]

Sorry - forgot to erase the first sentence. The Culmann Method is good for active (and I believe for passive too).

 

[alwayslearning123]

Thanks Everyone. NAVFAC DM7 has the answer. I Also found an equation for Rankines passive earth pressure for sloped back fill. It seem as though it is just calculating the weight of the wedge though.