Slide Rail System with Tie Back Provides Necessary Soil Support for Large Precast Tank Installation

A Southwest contractor would be installing a concrete cooling tank that was used in the project owner’s business manufacturing process. The concrete cooling tank would be precast and would need to be installed in three sections, with each section weighing about 90,000 pounds. The components would require an excavation of approximately 40-ft length, 16-ft width and 20-ft depth. The contractor’s competent person had classified the soil as a Type C-60 soil.The size and weight of the precast sections of the tank formed the initial constraint that each successive decision would need to incorporate. The precast nature of the tank components also created a need for the excavation to be free span in order for an easy and efficient installation of the components. There would also be an existing building that would be 12-ft from one side of the excavation, which would need to be protected during the installation process and would also limit site access.

The contractor contacted NTS to discuss possible shoring options for the project. After the presentation of a few systems, the contractor elected to use a site specific engineered SBH slide rail system with tie backs. The slide rail system would be installed progressively to prevent the soil raveling, which would help to prevent adversely affecting the existing building. The slide rail system’s tie back design would provide the free span excavation required to install the precast components within the pit. The contractor was able to quickly install the slide rail system and tie back system, which allowed the crew to move to the tank installation. The crew used a large crane to place the precast tank components within the excavation, addressing the jobsite working room limitations.The slide rail system performed very well, as the contractor was able to quickly install the system, perform the necessary work while the system was installed and then easily remove the system once the project was complete.