7NT provided geotechnical engineering services for this project. The planned space for the building inside the treatment plant facility consisted largely of trash and debris fill under six (6) feet of engineered clay fill soils. The area had served as a dumping ground for decades prior. After initial discovery of the trash and debris fill, projections indicated a deep foundation system would be needed for the 7,200 square foot pre-engineering metal building facility. The extensive deep foundation system would cost $750,000 to $1,000,000 above the planned and expected cost of the facility.
7NT personnel worked with the City, Contractor, and other design engineers to determine an innovative and cost effective solution so the structure could be completed within budget. 7NT engineers came up with a rammed aggregate pier solution to sufficiently stiffen the bearing soils to adequate capacity for the pre-engineered structure while also bridging the trash and debris soils to avoid future settlement and other foundational related issues. The project was completely successfully under budget. 7NT personnel also oversaw construction activities of the building foundation and structure. Specifically, the 82 rammed aggregate piers (up to 40 feet in depth) were fully documented upon installation for compliance with project documents by 7NT personnel.