Coulomb Failure Plane Angle 1

[RFreund]

Does anyone have a reference showing the equation for this angle? The only reference I have is NCMA Segmental Retaining Wall Design Manual. But I would like to see this derived in a different text.

EIT

http://www.HowToEngineer.com

 

[RFreund]

Forgot to add the equation includes:
-Backslope, wall batter and wall friction.

EIT

http://www.HowToEngineer.com

 

[FixedEarth]

It is on pages 4-14 through 4-17 of the 2011 Caltrans Trenching & Shoring Manual. Careful with the wall friction angle value.

 

[RFreund]

Thanks!

EIT

http://www.HowToEngineer.com

 

[RFreund]

So I finally got around to checking this out and I realized they don't include a coulomb failure plane or a failure plane equation that includes wall friction. Not a huge deal, but I just can't seem to find this equation anywhere.

EIT

http://www.HowToEngineer.com

 

[fattdad]

I think the reason there's no stancdard equation for all cases of soil strength is because Coulomb is a trial and error method. At least that's what I recall from grad school oh so many years ago. . .

f-d

¡papá gordo ain’t no madre flaca!

 

[dgillette]

fattdad - I think I remember setting it up with the force on the wall as a fn. of the base angle, taking the first derivative w.r.t. the angle, setting that to zero, and solving for the angle that gives the highest active pressure. As you know, however, that was a few years back.

Cheers!
DRG