AASHTO Retaining walls. LRFD Code

[ztengguy]

It as pointed out to me that when designing a retaining wall, surcharge is not added behind a wall for stability and eccentricity if it adds resistance for failure. Have anyone else been made aware of that?

I dont mean just the vertical portion either, the way it reads is all or none.

Any other ideas?

 

[spats]

The surcharge is either there or it isn't. Think of it as load combinations with or without live load. All codes state that "each load combination shall also be investigated with one or more of the variable loads set to zero", or something to that effect.

 

[steellion]

The surcharge should not be relied on to help for stability or overturning. You don't know that it will be there. Spats' analogy is a good one; it's similar to the D+W uplift case in which you are not relying on any live load to resist uplift.

 

[ztengguy]

But if it is there, then the vertical should be allowed to be used. A reviewer said that is incorrect, almost like it should have the vertical competent ignored but the horizontal not.