Infrastructure, infrastructure, infrastructure. It is the backbone of our nation and its upkeep and expansion will no doubt be a huge part in the nation’s economic road to recovery. Much of America’s infrastructure is composed of such underground utilities as water, sewer, electrical, gas, and telecommunication, just to name a few. Yet despite its vital importance to the country, upgrading underground utilities always start with a very humble first step: by digging a hole.
In Tampa, FL, four recent underground construction projects-though all very different-shared one thing in common: They all needed to safely shore really big excavations. Make that two things in common, actually, since they all chose Efficiency Production’s premier ClearSpan slide rail system to shore their big holes.
Safe Shoring
“It’s a good system, safe. You feel safe when you’re in the bottom of it working,” says Ronnie Jones, foreman with Seneca, IL”“based Mid-States (MS) Industrial, whose Tampa-based crew has been working in the largest configured ClearSpan slide rail system designed to date, a 44-foot-wide, 63-foot-long, and 24-foot-deep configured system. The MS Industrial team is casting in place a behemoth 39-by-58-by-24-foot truck-unloading hopper at the Big Bend shipping terminal in Gibsonton, FL, for project owner Mosaic Fertilizer.
“My crew was a little overwhelmed at the start. They didn’t quite know what to expect on how the shoring would go together,” Jones explains. “But once we got the routine on how it went down, they were all right with it.” To assist with installation, the manufacturer sent out its senior installer, Rod Austin, to work with the MS Industrial crew.
“That’s very typical of how it goes the first time contractors use our system,” says Austin, a shoring and shielding specialist in Efficiency Production’s special operations shoring division. “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 and 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.”
“Rod was really the one who led the way through it,” Jones added. “He was very knowledgeable and answered any questions we had while showing us how the structure went together and the best way to install the system.”
Precast Manhole Installation
On the other side of Tampa, in Wesley Chapel, FL, Pepper Contracting Services’ project superintendent Jeff Sevengy cites the ease of installation. “Everything went together very well, quicker than expected,” says Sevengy. “My guys liked it, understood it quickly, and did a great job putting it together.” Pepper installed a monolith of a structure-this of the precast variety-when it set a 12-foot-diameter (inside), 32-foot-tall round manhole into a 31-by-31-by-28-foot shored pit.
The first piece Pepper set was a large 14-by-16-foot precast concrete footer pad. Efficiency’s system was ideal for the task because ClearSpan’s design is unique to the industry in that it shores a large excavation without any need for cross-braces. The system stays entirely open by utilizing innovative waler i-beams on the outside of the system at the top, and inside the system to prevent deflection. The walers integrate into the Slide Rail system with the use of custom brackets with rollers that slide along the posts.
Slide rail is considered “positive shoring.” It is installed by sliding the panels into integrated rails on the 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. The advantage of Slide Rail over other shoring systems like trench shields is that there is absolutely no over-excavation, which means that pressure against the surrounding soil is maintained throughout the entire installation and removal of the system.
Additionally, Efficiency’s system comes with its exclusive ClearSpan panel pushing device that aids in the dig and push of the lower panels, which can be difficult to reach behind the inside waler beams by the excavator bucket. With the pushing device, the inside panels are pushed down from above the excavation using a large pushing pad connected to the inside panel on a free-moving rod within a floating guide bracket secured to the top outside panel. “It’s a great tool, and it would be much harder to install the lower inside panels without it,” Sevengy says.
Sevengy had used other manufacturer’s slide rail in the past, but chose the system for a simple reason. “Because of the depth we needed to go, Professional Shoring [now Efficiency Shoring and Supply] had the equipment to get us to the bottom, and they were able to get it to the job site quickly,” Sevengy says.
Efficiency Shoring and Supply is an official Efficiency Production factory-direct sales and rental company. Efficiency Shoring’s Paul Strazzula provided factory support on the Pepper project. “From the time the steel was delivered, installed, removed, and hauled away, it was a total of eight days, much quicker than anyone had expected,” Sevengy says.
Tandem Slide Rail Systems
For St. Petersburg”“based contractor Brasfield & Gorrie, the no over-excavation advantage of slide rail was absolutely critical as the contractor recently installed not one, but two Slide Rail System next to each other, shoehorned into one city block right in the middle of a residential neighborhood. Both slide rail systems were shoring pour-in-place structures on the city of Tampa’s UCAPP stormwater pump station project. The work site was very tight, with little more than the width of the track excavator separating the two pits. The north system was a three-bay multi-bay slide rail system, measuring 29 by 46 by 14 feet. The south system was a ClearSpan system that was 38 by 44 by 20 feet deep.
