ACI 318 defines a deep beam as:
9.9.1.1 Deep beams are members that are loaded on one face and supported on the opposite face such that strut-like compression elements can develop between the loads and supports and that satisfy (a) or (b):
(a) Clear span does not exceed four times the overall...
I am working on a transformer replacement project. The new transformer (~330kip) will be located at the same location as the existing transformer so they want to reuse the existing foundation elements as much as possible. The existing foundation is a 3ft 'T' shaped pile cap on (9) 18" dia...