Steel Sheeting Frame System Utilized on a Wastewater Treatment Plant Project

A Gulf Coast Florida water treatment plan was undergoing construction to increase its capacity. As part of the project, the utility contractor would be drilling shaft foundation piers as part of a poured-in-place lift station package. The project called for the excavation of an approximately 14-ft deep and 24-ft squared pit in Type-60 soil.

Given the presence of an existing wastewater treatment plant, the site had existing wastewater processing tanks surrounding the excavation site that would need to be reasonably protected from soil disturbance while excavating. The contractor thus needed a four-sided system that could meet the pit size while providing a free span excavation.

The contractor contacted National Trench Safety to discuss the project.  After reviewing potential options for the project, the contractor elected to use a steel sheeting guide frame system. The contractor had previous experience renting this system and was very pleased with its function. The system is composed of steel sheeting frames that are positioned along the top of the excavation connected by corner posts.  Steel sheets are then inserted through the frames and pushed to depth to provide the necessary soil support for the excavation. The system helps to prevent soil raveling, which was a priority for this project to ensuring the integrity of the existing tanks. The system performed very well and the contractor was once again very satisfied with the equipment as well as the service level and timely delivery of equipment provided by NTS.