Dirt-Tight Challenge

American Excavating, Ltd., headquartered in Saginaw, Michigan, was low bidder on a project for the City of Saginaw to construct a new cast-in-place concrete bypass chamber to combine a 60- and 90-inch diameter combination sewer. The project also included blocking-off the 60-inch sewer downstream in order to eliminate an abandoned manufacturing site’s stormwater from continuing to run into the city’s combined sewer system and treatment plant.
The challenge for American was the need to excavate and expose both pipes, which run parallel but at slightly different grades, then set up a system to support the concrete lines in order to dig out below the inverse of both pipes, and finally cast-in-place a new bypass junction chamber tying the two lines together. Oh, and American needed to safely shore a pit that would encompass all of the above.

Featured Image: The challenge for American was the need to excavate and expose both a 60- and 90-inch sewer lines which run parallel to each other but at slightly different grades, then set up a system to support the concrete pipe.
Above: Saginaw, Michigan-based American Excavating, Ltd. are Zac (left) and father Steve Birnbaum.
SELECTING THE CORRECT SHORING SYSTEM
“There were a couple of factors we needed to consider when looking for a shoring system,” says Zac Birnbaum, American Excavating’s project manager. “We knew the excavation was going to be open for a while, so trench boxes would not be the best choice,” says Birnbaum. “Also, the excavation was in the middle of a road and according to the City (of Saginaw), needed to be ‘dirt tight’ so over-excavating the hole wasn’t a possibility.”
“We considered sheeting, but that would require us to take out both the 60- and 90-inch sewers and use bypass pumps the whole time, which would increase the cost of the project dramatically,” continues Birnbaum. “Instead, we went with an Efficiency Production Slide Rail System because we could use panel guides and short lengths of KD-6 sheeting to tightly shore around both of the big pipes, without having to remove them,” Birnbaum explains.
“Really, Efficiency’s Slide Rail System was just more cost effective than sheeting,” concludes Birnbaum.
PERFECT SHORING SYSTEM SOLUTION
Efficiency’s Universal Slide Rail is a component shoring system comprised of steel panels and vertical steel posts. The highly versatile system can be used in a variety of configurations. Efficiency’s Slide Rail System can be configured into small four-sided pits; an obstruction-free ClearSpan™ configuration; or in a Multi-Bay™ configuration to install large tanks and structures or lengths of pipe more than 40 feet.
With the trench protection system decided, Birnbaum’s next call was to Efficiency Production’s Special Operations Shoring Division. Rod Austin, Efficiency’s senior slide rail installer and shoring specialist—now the company’s vice president of sales—took Birnbaum’s call. “Zac sent me the prints to figure out how we could shore the hole without shutting down the two sewer lines,” Austin explains. “I knew we could do it with Slide Rail by incorporating our Shore-Trak Panel Guides to shore around both pipes as they passed through the excavation,” says Austin.
PREVENTING SEWER LINE SHUT DOWN
Slide Rail is installed by sliding the steel panels—similar to trench shield sidewalls—into integrated rails on the vertical posts, and then pushing the panels and posts incrementally down to grade as the pit is dug; a process commonly referred to as a “dig and push” shoring system. Efficiency’s Panel Guides replace the Slide Rail panels that slide down the open-faced inside rails on the posts. That allowed American to place short lengths of KD-6 sheeting and a few road plates through the 7-inch slot in the Panel Guides to tightly shore around the existing sewer lines on both ends. Panel Guides are an exclusive feature of Efficiency Production’s Slide Rail System.
With equipment rented factory-direct from Efficiency Production’s manufacturing headquarters in Mason, Michigan; and with Tim Hurst, shoring specialist in Efficiency’s “Special Ops” Division on-site to offer installation assistance, American’s crew installed a two-bay, 4-Sided Multi-Bay™ configured Slide Rail System.
The total dimensions of the shoring system were 26 feet wide, 41 feet long, and 24 feet deep. Multi-Bay™ utilizes Efficiency’s exclusive Parallel Beams that roll up and down the slotted rail on the inside face of the linear posts and have spreader collars which pin standard trench box spreaders for cross-trench support.
All told, it took American just 2 months to cast-in-place the approximately 30 foot long, 10 foot wide, and 10 feet tall bypass junction chamber, plus two 10 foot tall personnel-access chimneys.
American Excavating’s heavy equipment on the $280,000 project was a 345D CAT excavator, a 950G CAT front-end loader, and a 320C CAT excavator with hoepack for compaction.
Saginaw-based American Excavating, Ltd. was founded in 1990 by Steve Birnbaum. In the construction business for more than 30 years, Steve got his start working for his father and uncle, Fritz and Al Birnbaum, at Valley Asphalt which is now part of Saginaw-Ace Paving. Steve’s son, Zac Birnbaum, joined American Excavating in 2004. ■
 
About the Author: James McRay is the director of marketing & media for Efficiency Production, Inc. He can be reached at 800.552.8800; jmcray@efficiencyproduction.com. Efficiency Production, Inc., “America’s Trench Box Builder™,” provides the widest selection of standard and custom trench shielding and shoring systems in the industry. All products are P.E. certified to meet OSHA and MIOSHA requirements. www.efficiencyproduction.com.
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Modern Contractor Solutions – December 2015
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