drilling in a duct bank

[rhunter@proconconsulting.]

new construction - nothing energized as yet
high voltage duct bank poured when the building foundation and parking deck were poured

subsequently, a subcontractor drilled into the duct bank to hold supports for another utility device

the MEP designers are having a cow and the GC says it is OK

Does anyone know a code reference that prohibits drilling into or otherwise attaching anything to a duct bank?
Stories and case studies are welcome too.

Thanks,
RH

 

[Rick 0920]

The duct bank requirements that I have done in my career have been dictated by the serving utility. There is nothing in the NEC that either accepts or prohibits this that I know of. I would contact the POCO and see if you get your answer. Let me know please.