Case History: Iterative Foundation Design for a New Women’s Hospital in Orlando, Central Florida

The new Florida Hospital for Women is located on the main campus and will provide a new era of high tech care for the women of Central Florida. The twelve story building includes a full basement and is situated on a tight urban site. A cast in place reinforced concrete flat plate structural framing system was selected. Column loads varied from 1800 to 3900 kips. The geotechnical field explorations included SPT borings and CPT soundings to about 100 feet deep. The subsoil consisted of medium dense sand followed by medium stiff clays and silty to clayey sands underlain by the Hawthorne Group soils. Iterative foundation design process was developed and executed between the structural and geotechnical engineers to design the most economical foundation system to support the building. Settlement analysis was performed utilizing numerical modeling to provide accurate subgrade reaction modulus. A soil mat foundation was selected which offered better stress distribution and minimized differential settlement; however total estimated settlements were in the order of 3 inches. The design team along with the owner agreed to take the risk of approving the building total and differential settlement and account for it in the final design. Few columns were instrumented and monitored for settlement throughout the construction process. Recorded settlements were in the order of 50% of the estimated settlements. This paper summarizes the structural components, the geotechnical aspects, foundation design, and construction challenges of the project.