A Northern Florida contractor was tasked to install three 24-inch and two 48-inch pipe casings via boring underneath an existing tunnel on the grounds of a prestigious Florida University. The project would require an excavation cut for the bore and receiving pit. The bore pit would require a linear run of 37-ft with a width of 33-ft and a depth of 16-ft. The receiving pit would require a linear run of 33-ft with a width of 20-ft and a depth of 16-ft in a sandy clay mixture that the Competent Person classified as Type-C-60.
The project site presented several challenges such as the limited work span area and the close proximity to adjacent structures. The area to be excavated was located underneath an existing tunnel that housed active electric, sewer, phone, and data lines. The project also contained utility lines that were not marked or designated on any of the plans which increased the level of difficulty for the excavation. The contractor on site would have to verify and test all discovered lines. The project would require a protective system that could accommodate the bore and receiving pit for the casing installation while addressing the safety of the adjacent running utility lines. The protective system would need to be flexible enough to allow the verification of unknown lines and the construction of a manhole inside the pit once the insulated chill water lines were installed in the casings.
After carefully reviewing several protective systems, the contractor selected a site-specific slide rail combination system. The slide rail system is a unique flexible underground safety system that works well when encountering crossing utilities or unforeseen underground obstacles. The project required additional safety and open span system. A slide rail system can be used with a wide range of applications and paired with several modular components. The contractor was extremely satisfied with the service provided by the in-house team of engineers. Additionally, the contractor was also impressed with the flexibility provided by the site-specific slide rail system which addressed all of the challenges.