EXTREME SHORING: Minn. contractor uses largest, longest trench box from Efficiency Production to lay big pipe in New Mexico

There are only a few options available to a contractor when laying 72 in. pipe in 40 ft. lengths. If possible, open cut is the preferred method, but what does a contractor do when he wants to use a trench box? Forty-foot lengths of pipe do not easily fit into most trench shields; then don’t even fit easily into two trench shields end-to-end. Such an extreme challenge requires an extreme shoring solution.

Minnesota’s S.J. Lewis up for the challenge
S. J. Lewis Construction, Inc. of Waite Park, Minnesota, was recently awarded a $22 million contract from the City of Albuquerque, New Mexico, to install a new raw water transmission line in Albuquerque which will divert water from the Rio Grande to a new state-of-the-art Water Treatment Plant. The Water Treatment Plant is scheduled for completion in 2008.

S. J. Lewis is subcontracting from Bradbury Stamm Construction of Albuquerque, New Mexico; the installation of 17,500 linear ft. (3.3 miles) of 72 in. diameter spiral-steel pipe in 40 ft. lengths. Each pipe is cement lined, tape wrapped and mortared. One stick of pipe weighs 32,000 lbs.

In several areas along the pipeline’s progress, access is severally limited, especially where it runs along the right-a-way of Paseo Del Norte Highway. In this stretch, the pipeline trench needs to be cut vertical, mere feet from the road’s shoulder and very near adjacent buildings in some spots. With the option of sloping and sheet piling (due to potential vibration damage) eliminated, a trench shielding system becomes the desired option.

S.J. Lewis seeks help from United Rentals Trench Safety Division
“For big pipe lengths, we frequently have used a combination of shorter trench boxes, sometimes abutted with arch spreaders,” says Kenny Zajac, S. J. Lewis’ Project Superintendent. “For this project, however, it’s so much faster and easier to have a complete open-span shield in order to lay the 40 ft. long pipe completely horizontal, with no obstructions, spreaders, or arches in the way. Essentially, we don’t have to adjust the angle of the pipe when we are laying it, or walk it under arches,” Zajac adds.

In order to obtain a trench box that would meet the requirements of the project, S.J. Lewis contacted United Rental’s Trench Safety Division. United Rentals in turn contacted Efficiency Production, Inc.–a leading trench shielding and shoring manufacturer headquartered in Mason, Michigan–who are well known for their ability to custom-engineer and design shoring systems to meet tough project challenges.

Manufacturer Efficiency Production, Inc. provides shoring solution
For Efficiency Production Vice President of Engineering, Mike West, the solution was to “build for them one of the largest, longest steel trench boxes that we have ever designed and manufactured.” The result was the timely design, engineering, and production of a 50 ft. long, 10 ft. high steel trench shield with 12 in. thick sidewalls. To accommodate the 6 ft. diameter pipe, the box incorporates a 5-pipe independent spreader system with 10 ft. long, 10 in. schedule-120 steel spreader pipe with reinforced side-wall collar oversleeves.

The depth of the trench ranges between 15 and 17 ft. in very fast-moving sandy soil. The project also includes five highway bores involving 96 in. casing, which S. J. Lewis subcontracted.

Trench box works great on project
Kevin Collins of Boyle Engineering – the project’s Design Engineering Firm – had this to say about the project: “With the fast-moving sandy ground, many times a trench box is the only way to get the trench down to grade near adjacent structures, and certainly it keeps all the workers safe.”

S. J. Lewis is using a Cat 385 excavator to set the pipe and handle the trench shield. A PC 600 Kamatsu is used on the backend of the box for backfill and compaction.

Primary Contractor Bradbury Stamm’s Safety Director, John Brown, also had high praise for S. J. Lewis’ work installing pipe: “With those 40 ft. joints of pipe, there are spots were they just could not do this without that 50 ft. trench box. It’s keeping adjacent buildings and roads from being seriously compromised, and they’re moving less dirt which saves them time and money,” Brown adds.

New water supply part of San Juan-Chama Drinking Water Project
The Drinking Water Supply Project is one of six work projects in the Albuquerque Bernalillo County Water Utility Authority’s San Juan-Chama Drinking Water Project. The project is necessary because Albuquerque’s current water system relies entirely on pumping groundwater from an underground aquifer; which is being seriously depleted. San Juan-Chama will provide 70% of the metropolitan area’s future water. For more information on San-Juan Chama, visit www.sjcdrinkingwater.org.

S. J. Lewis was founded by James Schueller in 1983. They currently employ over 400 people and specialize in underground utility work, specifically large diameter pipe installations. They are members of the National Utility Contractors Association and the Minnesota Water-Well Association.

Efficiency Production, Inc., “America’s Trench Box Builder™,” provides the widest selection of standard and custom engineered trench shielding and shoring systems. Efficiency’s versatile products are designed specifically for safe and cost effective installation of utility systems and infrastructure improvements. All products are P.E. certified and engineered to comply with OSHA excavation and trenching standards.
 

S. J. Lewis Construction, Inc. of Waite Park, Minnesota, installs a new raw water transmission line in Albuquerque, New Mexico, which will divert water from the Rio Grande to a new state-of-the-art Water Treatment Plant.	Access is severely limited where this pipeline runs next to Paseo Del Norte Highway. In this stretch, an Efficiency Production trench shield allows Lewis to dig very close to the road without disturbing it or surrounding structures.
In order to lay the 40 ft. long pipe completely horizontal with no obstructions, Lewis chose to purchase a 50 ft. long, custom manufactured trench shield from Efficiency Production, Inc.	Lewis is using the largest and longest trench shield ever designed and built by Efficiency Production, Inc. The trench box is 50 ft long, 10 ft. high, and has 12 in. thick sidewalls.