Force transfer in fixed pile cap

[allimuthug]

Hi ,

I have a fixed single pile cap . The pile cap has to transfer moment to the pile. The distance between the vertical rebar in pile cap and pile re bar is 100 mm . If 75 mm offset of pile is considered the distance between vertical rebar and pile rebar becomes 175 mm .
In this case how the moment from pile cap would be transferred to pile if i dont want to change any reinforcement details ,
Please see the picture attached .
Link

 

[KootK]

I'd use a strut and tie model considering the anticipated eccentricity. Interestingly, if you throw some headed bar anchors on your pile bars, it's basically your anchor bolt problem upside down. Bit's a pretty safe bet that you'll need to change your detailing a bit.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[allimuthug]

can you mark in picture ... I couldn't understand it.

 

[allimuthug]

Also please let me explain if i didn't change that detail what would happen.

 

[KootK]

I'm afraid that I'm not at the office today. I'd be very tempted to just run your bolts to the bottom of the cap and your pile bars to the top. This might effectively lap the anchor bolts and pile bars, effectively bypassing the cap.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[KootK]

If you don't change the detail, it might not work for transferring the moment. Only you know the actual numbers of course.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[allimuthug]

Oh i know that it is easiest way to transfer force directly . I am restricted in doing that ,As some case due to construction there much possibility of anchor bolt clash with pile rebar. Can you explain how that detail works and any other alternative ,

 

[allimuthug]

The concrete between the pile cap rebar and pile rebar would transfer tension or not , Is there a possibility of non contact splice .
Else suggest my any other solution .

 

[KootK]

Is there a possibility of non contact splice?

In this case, that's precisely what the STM model is: a way to evaluate a non-contact lap splice.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[humanengr]

I assume, once you transfer the force couple down to the pile, the pile is designed to resist the moment.

If your column loads are signficant, I would consider adding a pile.

By the way, what are you considering for the stability of the single pile? Just lateral soil resistance? Two piles tied together may be considered per IBC - but read the details and fine print.