H-pile to pile cap attachment

[JTPE]

I am looking for clever ways to attach a steel H-pile to the concrete pile cap...considering uplift.

I know of the steel plate welded to the top, but I have overthought that and am not comfortable with a potential cavity under the plate.

I have used a "V" shaped rebar threaded through a hole in the top of the pile and extending vertically into the cap, but there was some difficulty during construction. The bar was tough to deal with around the bottom mat of bars and sequencing with the formwork and bottom mat placement was also painful.

Does anyone have any ways to have a positive connection between the steel pile and the pile cap?

Thanks in advance.

 

[PEinc]

How about headed shear studs or welded angles or rebars?

 

[lkjh345]

Concur with PEinc. Have also used welded shear studs attached to top of H-pile for uplift conditions in the past.

 

[csd72]

We have used a hooked rebar welded to the web of the H-pile.

This seemed to work well, and was easy for the guys to work around on site.

 

[ChipB]

I think you'll get prying action if you use angles.

I don't like welding rebar. I actually have never allowed it because it is so brittle.

Here you go:
1) Conceptially flip your pile so it looks like a column.

2) Calculate what size headed anchor bolts you would need to develop the tension. Try to stay with A307/A36

3) Determine the depth of concrete you need to develop. (You might need to go with plate washers on the bolts to develop the tension.)

4) Weld A36 threaded bars meeting your design to the four corners of the outside flanges using a flare bevel weld. You'll need to calculate your length of weld.

5) Tack weld the nuts on. (double nut it if the plate washers if needed)

That should take care of it. I'm sure there are other ways, but this is my preference. If you only need two bolts, locate them at the centerline of each flange (along the web).

Chip

 

[JTPE]

Thanks for all of your input!

I like the ideas of having a connection that looks like a concrete pile connection (vertical dowels). I tried to stay away from welding the "dowels" but your responses show its really not that big of a deal.

THANKS.

 

[csd72]

ChipB,

Welding of reinforcement is okay as long as you specify it done to the approriate procedure

ANSI/AWS D1.4/D1.4M:2005 covers this.

As long as it is done correctly then it is no more brittle than any other welded connection.

Regards

csd

 

[SlideRuleEra]

Instead of a "V" shaped bar thru a hole in the web, I have used a straight bar. Not as good a "V" bar, but good enough for a lot of applications - for moderate uplift the rebar cage in the cap is going to keep this horizontal bar from pulling out the bottom.

http://www.SlideRuleEra.net