Contractor wrangles 50 foot long, large diameter pipe for Texas water facility upgrade
The Austin (Texas) Water Utility recently awarded an important underground utility project to Layne Heavy Civil, Inc.—headquartered in Fairburn, Georgia. Layne is in the process of installing 17,500 linear feet of 54 inch diameter cement coated pipe, mostly in joints 50 feet long.
The Martin Hill Water Transmission Main will provide water for the Northwest and North quadrants of the City of Austin. It is part of the City’s Strategic Water Facility Plan and when completed will connect the Martin Hill Reservoir to existing city water pipelines. The Martin Hill Reservoir is the largest steel potable water tank in the U.S and can hold more than 35 million gallons of fresh water.
INSTALLING THE MAIN
The majority of the main is being installed via open cut excavation; however, many stretches of pipe installation are being installed 15 to 20 feet deep and require a series of long trench boxes to accommodate the 50 foot lengths of pipe while keeping the crews safe in the trench.
“Layne originally requested 8-foot tall trench boxes with arches on the end,” explains Mike Ciotta, regional sales manager at Efficiency Shoring & Supply’s Dallas/Ft. Worth Branch Office. Efficiency Shoring & Supply rented and supported all the trench safety equipment and shoring for the project.
Continues Ciotta, “However, it was so difficult maneuvering the 50 foot joints of pipe, Layne decided they needed 10-foot tall boxes. We didn’t have any long 10-foot tall trench shields left in our yard, but because we’re (manufacturer) Efficiency Production’s factory-direct branch, we were able to get a 10-foot by 32-foot box built and shipped here to Austin, so there was no downtime on the project,” Ciotta says.
There were also instances where Layne needed to tunnel the water main: under a busy intersection for 960 linear feet of the 72-inch casing pipe and under railroad tracks for another 379 linear feet of 72-inch line. These instances require up to 45 feet deep tunnel shafts to be excavated and shored; but because of the versatility of the Efficiency trench shields, Layne was able to reutilize the trench boxes on rent to shore the tunneling pits.
In total, more than 25 large trench shields were utilized by Layne, including Efficiency trench boxes sized 10×32, 10×24, 10×16, 8×16, plus two spreader arches. Layne also had road plate and a 12-yard Stone Mizer® bedding box filled with clean loose rock for backfill. Layne’s heavy equipment for the project includes:
- John Deere 870’G’ with a 4-yard bucket for the main trench digging
- John Deere 470’G’ for moving the back shield and backfilling the trench
- John Deere 844 Loader to unload the 22,000 lb. steel pipe
- John Deer 644 Loader hauling bedding stone to the stone mizer
- Trencor Rock Trencher for pre-trenching in the limestone rock areas
THE TRENCHING PROCESS
Installing the mammoth pipe in the trench boxes is a bit of a process. Two trench shields are used with hi-clearance arch spreaders on abutted ends. That provides enough vertical clearance for the expert excavator operator and crew to thread the pipe into the boxes under the arches. The boxes are then shifted to protect the personnel in the trench who are filet welding the joints from inside the pipe.
“The boxes are working really well,” says Layne’s Fred Lester. “Right now were on Section C of the three-part (Martin Hill Water Transmission Main) project. We’ve already got Efficiency working on the shoring plan for Sections A and B, where the ground will be more rock than soil,” Lester adds.
The project is contracted to be completed in early 2015; however, Lester says that they hope to be finished by this fall.
Layne Heavy Civil delivers sustainable solutions to government agencies and industrial clients by performing design and build services of critical water and wastewater treatment facilities and pipeline installation. More information is located at: www.layne.com.
With Texas Branch Offices in Houston and Dallas/Ft. Worth, Efficiency Shoring & Supply is an official Efficiency Production, Inc. factory-direct sales and rentals company.
Efficiency Production, “America’s Trench Box Builder™,” provides the widest selection of standard and custom 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 to meet OSHA standards.
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About the Author James McRay is the director of marketing and media for Efficiency Production, Inc. He can be reached at 800.552.8800; jmcray@efficiencyproduction.com. For more information, call Efficiency Shoring & Supply at 800.220.8707, or visit www.efficiencyshoring.com.
Modern Contractor Solutions, June 2014
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