Can prestress wires in PC. pile sustained tension in pier

[Gtoyo]

Could anyone has idea about using prestress wires in PC. pile to transfer tension in pier. My colleague in office say that in case of piles subjected to tension due to wind such as in PEB building were penetrated too short and dowel have to cut out to reach design pile top level, we can sonsidering to use their prestress wires to transfer this force. For me i'm disagree with him.
Did somebody out there has experienced with this. In case of can, how can we calculted embeded length to concrete. I cant find some helpful sources in ACI for embedded length of these wires except doformed and weld wire fabric.
Assume that a pile was subjected to 16 kips in tension and no problem from soil only the way to transfer tension through pile only.

Thanks.

 

[dlew]

Gtoyo,

We have used the prestressing strands (3/8" to 1/2" in diameter) in the concrete piles to transmit the tension forces from the pile cap to the piles. We specify the additional length of pile needed to provide the length of the strands required to transmitt the tension forces by bond with the concrete. The top of the pile has to be cut after driving, without damaging the strands. The strands have to be supported from the pile cap rebars to insure they extended into the pile cap and do not lay flat on the bottom.

As an alternative, rebar dowels could be epoxy set in drilled holes in the top of the pile.

Regards

AEF

 

[Gtoyo]

Dlew
In case of PC. wires , do you have an idea how to calculate development length to tension force.

 

[dlew]

Gtoyo,

A prestressing strand manufacturer could answer the question about the developing length beter than I could. It has been quite a while since I designed my last transmission tower foundation using prestressed concrete piles.

regards

AEF

 

[abhio]

If you have exposed the wires anyway, why not simply tension them and have anchorages in chases cut in the sides of the pile caps? Abhijeet Oundhakar
Design Engineer
Rashid Al Owais Engg. & Consulting
Sharjah, UAE