Repair of Pile Cap Foundations Using Strut-and-Tie Models

The subject of this paper is the structural assessment and repair of multiple large pile cap foundations. A combination of high temperatures during early hydration and inadequate steel reinforcement resulted in large cracking that compromised the structural integrity of the caps to the extent that repair and modification were necessary. New pile caps, placed on top of the existing caps, were designed to support the existing loads and superimposed loads that would result from a future buildout. The new pile caps were designed in accordance with the strut-and-tie provisions of the 2002 ACI 318 Code and constructed with a high-strength, self-compacting concrete.