150 Charles St. was a project where The Laquila Group, Inc. worked very closely with ownership and its consultants to come up with a value engineering proposal to significantly reduce the cost of the foundation work. The project was also quite challenging due to the fact that the existing building facade remained in place for the entire duration of the project, making access for material and equipment into and out of the site extremely challenging. The excavation was also surrounded on two sides by buildings that needed shoring and support.
A soldier beam and lagging SOE system was installed with tieback supports, and a wellpoint dewatering system was utilized to maintain a dry work site. Once excavation was completed down to design grade, permanent and temporary tiedowns were installed to resist hydrostatic pressure, a waterproof membrane applied, and the concrete mat foundations were poured. Once the foundation walls were completed, the site could be backfilled and the concrete walls and slabs could be tied in to the existing building facade, providing a dry, leak free cellar even after the dewatering system was shut off.