Use of Shear Friction to resist one way shear in Footings and Pile caps

[humanengr]

I'd like to ask if anyone has utilized shear friction to resist one way / deep beam shear in footings or pile caps.
The foundations are monolithically built.
The one way shear (as opposed to punching shear) governs the design of the footing / pile cap.
Rather than increase the depth of the footing or specified conc. compressive strength,
I would like to take advantage of the footing reinforcement to develop shear friction across the shear plane.

Further, if I assume one layer of reinforcement resists flexure, is it acceptable to use the other layer
to develop the shear friction. In other words, can top layer steel or bottom layer steel be used
for this purpose?

I could not find any info. in ACI stating where the reinforcement used for shear friction must be placed
(mid-depth or, is 3 in. from top or bottom acceptable)?

 

[r13]

Shear friction reinforcement will be effective only after a slip plane has occurred, I don't think the large deformation is acceptable in any situation.

 

[hokie66]

The whole concept of shear friction is that the reinforcement provides a clamping force. Reinforcement which is in the compression zone cannot provide clamping. It is one fallacy of the theory that this is not made clear.

 

[HTURKAK]

I suspect for , how did you calculate the design shear force . The critical section for one-way shear is located at a distance d from the face of a column and the shear is calculated assuming the footing is cantilevered away from the column .


If the design shear force exceeds the one-way shear design strength, YOU ARE EXPECTED TO INCREASE the footing thickness.


What is the reason for you don't want to increase the depth of the footing?

Pls provide more info. to get better respond ..

The following picture depicts the locations of critical sections for one way and punching shear..