A coastal, South Carolina contractor recently installed several manholes as part of a pump station improvement project. The excavation would require a linear run of 12-ft with a width of 16-ft and a depth of 20-ft. The contractor on site classified the sandy soil as Type C-80 soil.

The contractor would be contending with a 10-inch force main within 2-ft of the excavation and a muddy entrance, which made it difficult to access the pump station located next to a major highway. After reviewing several protective systems the contractor selected the slide rail system. The slide rail system would provide positive soil support during the excavation which allowed for an open span area. The slide rail system installation began by pushing slide rail posts into the ground.

Steel slide rail panels are threaded along the corner post inside tracks and pushed to depth in a dig and push method ahead of the excavator’s cut. Additionally, steel sheets were inserted through pile chambers along the open ends which provided the flexibility to accommodate the incoming lines to be tied into the manhole. The contractor was very satisfied with the slide rail system’s performance, as it provided a practical solution to the manhole installations.