Maritime Plaza consists of two new four-story commercial buildings on a 12-acre brownfield site. Each building is approximately 180,000 SF. The site is the former home to the East Station coal-fired gas manufacturing plant, which was demolished in 1985. Existing utility structures and foundations were left in place and covered with imported fill varying from six to 26 feet in depth, most of it uncharted.
Delon Hampton & Associates (DHA) civil and structural engineers faced a number of challenges in preparing the site for development. It was determined thate the simplest, most cost-effective foundation solution, which was responsive to the site’s environmental constraints, was to compact the soil in-situ, to accommodate a shallow spread footing system. This approach would minimize the on-site soil disturbance, limit soil discharge off-site, and minimize the impact of existing buried foundations and utilities on the new construction.
The project team pioneered the use of Deep Dynamic Compaction to achieve allowable soil bearing values, where the subsurface cannot be removed or disturbed. The success of the entire development hinged on reducing the length of the environmental permit cycle and on controlling unpredictable site preparation costs. Deep Dynamic Compaction was key to that success.