Our Kansas City location was approached with a job to replace an underground pumping station that was located within 10ft of a multi-million gallon water tank. Since the excavation was to be approximately 13-14ft deep and close to the tank structure, the contractor was thinking of using sheet piling to shore the excavation.
A rental of a slide rail system was proposed, as an option to sheet piling the excavation. The excavation size was 20’W x 38’L x 13’D. It also needed to be a clear span, to allow the prefabricated pumping station to be installed. Once the proposal was presented, the customer decided to go with the slide rail shoring system instead of sheet piling. The customer let us know later that the slide rail rental was approximately ½ the cost of the sheet pile proposal they had received.
When installation began, we encountered a limestone rock ledge approximately 3’ thick. Then below this it was light gray shale. So, we couldn’t do the typical dig/push install method due to the rock ledge and shale.
In consulting with the contractor the decision was made to install the system by digging to the final depth and building the slide rail system in the trench. Once complete, excavate out the inside of the system. This method worked, and we were able to install the system in about 2 days.