Mega-Size Sewer Lift Station Construction Requires Unique Shoring System

January 2010 Vol. 65 No. 1
Weihe and ESI were able to come up with a modified ClearSpan slide rail system with the addition of sheeting on the deep end.

The size of this slide rail system was most ambitious for a contractor who was using it for the first time, but they had no problems. “At first, there was some trial and error in finding the best technique to install the slide rail parts in the hard clay, but so far it’s been wonderful,” said Mike Matlock, Weihe’s project superintendent. “We got the system in the ground in good time. The waler beams have been critical, in that they move up and down, which makes it easy to extract when we start to pull the sheet out as we backfill on that deep end.”

To assist Weihe with the initial slide rail installation, Efficiency Production sent on site their Slide Rail Systems Manager Greg Ross. “It’s always interesting to see the reaction of contractors the first time they use slide rail,” explained Ross. “The first day, they usually are intrigued on how and if it’s going to work; the second day, there is usually a bit of consternation as they have to overcome unexpected ground conditions as they are trying to put the system in one piece at a time; but by the third day, they really get the hang of it, and they really start to figure out that this is a great system.”

Efficiency Production’s slide rail is unique in that it is installed and removed incrementally, which allows the trench to be properly shored throughout the entire installation or removal process, always protecting workers from a trench wall collapse.

Before actually digging the pit, the excavation was benched down the first five feet. A CAT 311 mini excavator was then set in the hole to complete the excavating. The lift station was formed with two-foot thick walls, in two chambers.

Additionally, Weihe installed two 20-foot tall precast manholes; one that had an eight-foot outside diameter, and the other a five-foot outside diameter. The lift station was completely formed up in only three months. Because the excavation was open for that duration, Weihe utilized the system’s integrated slide rail barrier posts and adjustable length hand rails which provided fall protection.

Weihe Construction Inc. is a general site work and excavation contractor specializing in residential and commercial developments, including earthwork, sanitary sewer, storm sewer and waterlines.

Buyer's Guide