GerryBertier
Structural
I have a situation where the concrete contractor placed footing too thin. Instead of the specified 13'x8'x1'-6", it is 13'x8'x1'-0".
Punching shear, one-shear and flexure in both directions do not check.
I'm thinking of doing a grid of #3 U-Stirrups (or U-dowels / hairpins) to transfer horizontal shear between placements at the horizontal cold joint.
A couple of issues I have:
- Simpson and Hilti adhesives require 12" embedment for full development. Is there a way I can provide a percent of this embedment, by increasing my provided steel? I can base the percentage on Appendix D numbers relative to ultimate steel strength in tension. Make the U-strippups spaced far enough apart to not overlap breakout cones. Then increase my joint steel, which would decrease sustained tension in each dowel.
- In relation to the adhesive above, I suppose the adhesive is in sustained loading, since its an isolated footing with gravity loads - correct? Is this a good idea - adhesive under sustained load?
- In regards to horizontal shear, my Vuh at the joint (which is use in ACI 17.5.3) is actually the sum of components of shear flow (at that distance away from the column) due to bending in two directions since they are acting concurrently? - correct?
- Lastly, what is the minimum development for the hoop portion of the dowel? I'm looking at PCA Notes 318-11, sheet 12-12, and see no requirement.
Punching shear, one-shear and flexure in both directions do not check.
I'm thinking of doing a grid of #3 U-Stirrups (or U-dowels / hairpins) to transfer horizontal shear between placements at the horizontal cold joint.
A couple of issues I have:
- Simpson and Hilti adhesives require 12" embedment for full development. Is there a way I can provide a percent of this embedment, by increasing my provided steel? I can base the percentage on Appendix D numbers relative to ultimate steel strength in tension. Make the U-strippups spaced far enough apart to not overlap breakout cones. Then increase my joint steel, which would decrease sustained tension in each dowel.
- In relation to the adhesive above, I suppose the adhesive is in sustained loading, since its an isolated footing with gravity loads - correct? Is this a good idea - adhesive under sustained load?
- In regards to horizontal shear, my Vuh at the joint (which is use in ACI 17.5.3) is actually the sum of components of shear flow (at that distance away from the column) due to bending in two directions since they are acting concurrently? - correct?
- Lastly, what is the minimum development for the hoop portion of the dowel? I'm looking at PCA Notes 318-11, sheet 12-12, and see no requirement.
