Stem key in Cantilevered Retaining Wall

[Assayagr]

I'm in the process of designing a 21' cantilevered retaining wall and the shear at the base (between the stem wall and the footing) is a bit too high. I'd like to include a shear key as well as the effects of friction to increase my capacity but I'm not sure how to analize the key in this situation.
Any advice would be apreciated.

 

[BPA827]

Miecz:

The shear capacity I'm talking about is not shear friction, but from the concrete 2 sqrt f'c bd

 

[civilperson]

Shear from flexure and shear from soil pressure are the same. The shear found "d" away from the base is the design shear. The load diagram showing soil pressure is integrated to produce the shear diagram, thus it is the same shear that the makes the moment diagram or flexure.

 

[hokie66]

BPA827,

The OP was about developing the shear at the stem to footing interface. Thus all the talk about shear friction, keys, etc.

civilperson,

No one on this post is really arguing how to calculate the shear, just how to develop it across a construction joint. It is much the same situation which would occur if you made a construction joint in a slab right on the side of a supporting wall. That is avoided by casting the slab over the wall or keying it in. A cantilever wall is just a vertical slab, but for some reason it is not respected as such.