Unreinforced caissons ???

[cva1993r]

We have a bldg that is 30 stories high on concrete caissons as per the geotech report. the design engineer shows no reinforcing in the caissons that are about 30 ft below grade.......Is this common practice?


Thanks,

 

[eric1037]

Not if there are uplift or lateral loads, which are probable for a building of that height. In fact, in my experience, I have never seen a drilled pier without reinforcement.

 

[COEngineeer]

If there is no uplift then maybe its designed for sloped foundation. But you still need reinforcement. The should be at least (3)-#5 in there.

 

[oldrunner]

Are the caissons cased? What size are they?

 

[COEngineeer]

i didnt see the 30 stories part.. thoght it was 30' deep drilled piers. So yeah, there should be a lot of steel in there.

 

[cva1993r]

Thanks guys,

The caissons are not lined (lined only for the drilling) and vary in size from 6 ft to 10 ft in diameter.
The lateral loads when transfered to the top of the caissons I would think would require some type of reinforcing...even the minimum reinforcing....

I appreciate your inputs...

 

[Zambo]

30ft (10m) is not very deep for a bored pile - I assume they are founded in rock. Are they bored full depth with a casing? Those questions are only out of interest, I'm sure that there should be rebar cages.