Driven Pile - Pipe to Cap detailing 2

[MillR]

I'm a structural engineer designing a steel pipe pile foundation (as required by the soils report). It's for a small manufactured metal building with a pile cap at each column.

Question: Are typical pile-to-cap details more complicated than embeding the pipe 6" into the cap? There are small tension loads to address. I only saw requirements for concrete pile-to-cap detailing in the IBC.

Thanks.

 

[JAE]

With no uplift, and no significant seismic, you do see a "standard" detail consisting of what you describe - simply casting the top portion (6" to 12") of the pile in the cap.

If you have any net uplift on the cap/pile interface, then some sort of attachment is warranted. This depends on the type of pile you are using.

Steel Pipes: weld a cap plate on top that extends out from the pipe diameter a small amount. or weld headed anchors around the exterior of the pipe.

 

[aeoliantexan]

I'm a geotech, not structural, but I have seen hooked bars inserted in concrete fill in the pipe to transfer uplift from the cap to the pile. If the pile is not intended to be concrete-filled, a steel cap is necessary. Sometimes the concrete is cheaper than welding the cap on.

 

[AllStructure]

Make sure that your embedement depth can develop the fixed moment(if geotech has given you capacity based fixed head moment condition).

 

[MillR]

Thanks for the helpful answers.

We (contractor/architect/me) decided to go with grout filled pipe, as aeoliantexan suggested - the head connection is less of an issue and to address concerns about corrosion of the pipe. I will keep the cap in mind for future projects.