A contractor had been engaged to pour a cast-in-place foundation for a chemical injection building in Southeast North Carolina. The job required a 75 ft linear run, with a width of 10 ft and an excavation depth of 12 ft. The competent person on site had classified the soil as Type C-80 consisting of silty clay.
The project had a few site conditions which the potential protective system would need to address, although adjacent treatment tanks presented the most pressing challenge. The adjacent treatment tanks could not be relocated and soil disturbance would need to be minimized during excavation to maintain the integrity of the existing tanks. The contractor would also need a system that could provide adequate free span clearance to ensure that the crew would be able to efficiently pour the building’s foundation.
After reviewing several protective solutions for the project, the contractor selected a Beam and Plate System. The system was installed by drilling pilot holes into which beams to provide the base for the cantilever support of the system. Steel plates were then threaded through the beams open channels that allow steel plates to be inserted and pushed to the desired excavation depth. Beam and plate systems can be installed progressively and can help to minimize soil disturbance by pushing the plates to grade ahead of an excavator’s cut. The Beam and Plate System provided the contractor with a large free span work area, while ensuring the safety of workers on the site. The Beam and Plate System was a cost effective solution for the project, while NTS’ in-house engineering services provided a comprehensive site specific plan adapted to the contractor’s specific needs. The contractor was extremely satisfied with the system and the productivity it facilitated.