PROJECT OVERVIEW
Phoenix Project #2117
This project involved the construction of a new addition to the existing Building 55 on the MIT campus in Cambridge, MA. A portion of the new building addition required new foundations be constructed, while other structural loads were supported on existing foundations. The foundation design featured a total of 39 Ductile Iron Piles (“DIPs”), with an allowable compression capacity of 25 tons per pile.
Soil conditions consisted of uncontrolled fill underlain by of very loose sand and silt, followed by medium to very dense sand. The sand was underlain by Boston blue clay, a stratum that becomes increasingly soft with depth. DIPs were chosen over other deep foundation options due to their speed of installation, lack of spoils generated, and overall cost. This project employed exterior grouted DIPs to develop frictional capacity through grout-to-ground bond resistance along the pile depth, as well as end-bearing capacity in the medium dense sand.
One full-scale compression load test was conducted on a sacrificial pile. Thereafter, all production DIPs were successfully installed safely and on schedule, despite working within the confines of a very tight urban site.
