Effect of Backslope on Retaining Wall

[jqeng]

I have a stacked block gravity retaining wall with a 10 degree backfill slope. When I am calculating the pressure on the wall from the soil what height of backfill do I use?

http://files.engineering.com/getfil...5bf-b103-6a682faa3f36&file=20110324135231.pdf

 

[ishvaaag]

You may profit from the statement of Coulomb's active Push, that have provision for the slope, and uses your stated H.

 

[MiketheEngineer]

While I don't remember exactly how to do it - most examples (and software) for this calculation show how to handle this situation. Kind of like a surcharge load if I remember.

Find a good book or Google retaining wall calculations.

 

[WillisV]

http://en.wikipedia.org/wiki/Lateral_earth_pressure#Coulomb_theory

Backslope angle is Beta in the equations.

 

[csd72]

The surcharging method only works if it is a short slope above the wall, if the slope continues on for multiple times the retained height then you need to calculate it properly as per the previous post.

You will also need to check the overall stability of the slope.

 

[a2mfk]

I don't think that much slope will have much surcharge effect, since your H1 will not be significant until its several feet away from the wall. Why not just conservatively design for 1-2' of surcharge and call it a day?

 

[msquared48]

As Willis suggested, just calculate the Ka and Kp values for the appropriate angle of soil.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[RFreund]

oohh cross post well here's my response again:

If it is an MSE wall and your using NCMA design then the Ka value will be calculated using Coulomb equation which will reflect the backslope condition and therefore your height is H (the total height of the wall at back of wall).

Also see NCMA's Design manual for segmental retaining walls.

EIT