Site-Specific Shoring Used for Storm and Sanitary Sewer Upgrades

A Denver contractor was tasked to install an 84-inch storm sewer pipe and a 24-inch sanitary sewer line. The project required a linear run of 1000-ft, a width of 25-ft and a depth of 28-ft. The Competent Person on site classified the sandy soil as Type-C60.

The project site was located on the grounds of an existing road in a busy warehouse district. The road would be temporarily closed as the contractor completed the scope of work. Adjacent to the excavation stood two distribution centers with a 24/7 operational schedule. The contractor would require a system that could support the pressure load originated by the adjacent warehouse structures, provide a linear open span area for the installation of the storm and sanitary sewer lines and minimize the road excavation footprint repairs. Additionally, the contractor would need a system that could work around crossing utility lines found in the area.

The contractor understood the complexities of the project for which proper engineering would be required to secure the area. The contractor contacted NTS and after carefully reviewing several protective systems; a site-specific sheet pile and system 80 brace was selected. This unique system was composed of corrugated sheet pile driven to its required depth by drilling pilot holes. Beams and hydraulic struts were located ahead of the excavation cut. The contractor would decide not to weld the beams in place. Instead, the contractor decided to rely on a more hydraulic approach by simply pressing the hydraulic struts against the beams, which drastically reduced the installation process resulting in huge cost savings. The contractor was extremely satisfied with the flexibility, protection and cost savings provided by the sheet pile and system 80 brace.