Grady Memorial Hospital
Construction of a 16-story steel-framed masonry building and 12-story steel-framed masonry addition construction on top of existing 4-story building. Maximum column loads were 2,300 kips and 1,700 kips, respectively.
Soil conditions consisted of residual silts and sands.
The Geopier GP3® system was selected and Rammed Aggregate Pier® (RAP) elements were installed to support the mat foundation for Grady Memorial Hospital's 16-story tower. The ease of construction in the 22-foot deep excavated site made Geopier an attractive value engineering alternative. The project was completed in three days using two crews alternating 12 hour shifts. Maximum measured settlement was less than ¾ inch. RAP elements were used to support shallow spread footings designed for an allowable bearing pressure of 6,000 psf for the 12-story addition. Total measured settlement was less than ½ inch. An unexpected underground utility was found within one footing area and a redesign was accomplished during construction to bridge the utility, allowing it to remain in place. The design flexibility saved weeks of time and considerable additional costs.