Westfield Wheaton Costco
A 150,000 sf, two-story Costco was built on the site of a former Hecht’s store in the Westfield Wheaton Shopping Center.
During the exploration and design phase, soil borings in the footprint of the abandoned Hecht’s building were not possible since the project schedule and site development required the design to move forward. In the explorable areas, the geotechnical engineer identified that subsurface conditions consisted of 3 to 22 ft of silty sand and sandy silt uncontrolled fill underlain by residual sand. Column loads ranged from 200 to 1,400 kips.
In order to determine the most appropriate foundation system, GeoStructures worked with the geotechnical engineer and general contractor to develop several design and cost models during the design development stage. The design included spread footings with a nominal bearing pressure of 5 ksf supported on Cement Treated Aggregate (CTA) Geopier® elements in organic areas, traditional Geopier elements in non-organic areas, and natural soil in areas where uncontrolled fill was not present.