The 50-story FMC Tower at Cira Centre South has 830,000 Square Feet of rent-able space for commercial and residential usage. At 730 feet tall, it is the 6th tallest structure in Philadelphia, Pennsylvania. To accommodate the foundation contractor’s available equipment for installation of the drilled shafts (Caissons) and associated rock sockets necessary to support the building’s column loads, EEI developed an alternative foundation schedule to that shown on the contract drawings. With service limit state axial loads as high as 10,500 kips, EEI determined caisson diameters and rock socket length for each column of the building. Structural design of the caissons was performed by EEI, which featured for the highest column loads 8ft diameter shafts with 8,000psi concrete reinforced with as many as 48 #11 rebars. EEI was able to provide the alternative design of the foundations without delay to the foundation contractor’s schedule.