Village at Leesburg – Cobb Theater
51,000 sf luxurious megaplex theater, with every top-tier amenity available, including IMAX, D-Box, 3-D, and a cafe.
The existing site slope allowed for the northern portion of the building to be supported using spread footings on natural soils. The soil on the southern part of the site, however, was unsuitable for traditional spread footing support. The southwest portion required up to 10 ft of engineered fill to be placed. While the subsurface soils for the on-grade southeast portion consisted of up to 13 ft of clayey uncontrolled fill soils.
The geotechnical engineer recommended Geopier® technology for the southern portion of the building and spread footings on natural soils for the northern portion. Due to the dramatic grade change, two different Geopier® design methods were used in the southern portion. In southwest portion Geopier® elements were designed to support 10 ft of new engineered fill, and spread footings were founded in the new fill. In contrast, footings in the southeast portion bear on Geopier elements designed to support the footings directly. To minimize risk, Geopier elements were designed and installed to fully penetrate the uncontrolled fill soils. The combination of support systems allowed the footing system to be designed for a uniform 3,000 psf bearing pressure for the entire building footprint and meet the project settlement criteria. Both time and money were saved by the versatility of the Geopier® system on this project.
Bignell Watkins Hasser Architects
ECS Mid-Atlantic, LLC