Efficiency Production Shore-Trak™ from Stafford helps contractor meet strict DOT requirements

The rules were clear: do not make the excavation any bigger than the shoring system, and never allow the excavation walls to be unsupported at any time. These were the tough requirements set down by the North Carolina Department of Transportation (NC-DOT) when Charlotte (North Carolina) Mecklenburg Utilities let the $3.4 million project to install a 36 in. water main in the Andover-McAlway Rd. area of Charlotte. The new potable water line tapped into an existing 54 in. water main pipeline running directly under busy Providence Road.

Only one contractor, B.R.S. Contracting, Inc., of Richfield, North Carolina, had a solution for the shoring conundrum. B.R.S. partnered with local equipment distributor Stafford, and Efficiency Production, Inc. – America’s leading manufacturer of trench shielding and shoring equipment. Efficiency Production has a strong reputation for custom engineering trench shielding systems to meet unique shoring challenges.

“The DOT requires only ‘active shoring’ devices, which means that the trench could not be open at any time during the excavation, so traditional trench boxes were not an option,” says Roger Kimrey, Project Superintendent for B.R.S. “We called Efficiency months ago and they have been working with us all along to design, develop, and present a shoring system to the DOT that was an active shoring system that would work great for this project.”

Efficiency Shore-Trak™ Sheeting Guide Frame System meets DOT requirements
In order to make the tap on the existing 54 in. water main, B.R.S. needed to dig down 18 ft. in the middle of the busy four-lane road to the pipe, and then bring in the new 36 in. pipe through a 60 in. bore casing that had been bored 40 ft. from a cross street. The new water main connects to other fresh-water pipes in the area, as well as supplying two water towers.

The excavation needed to be as tight as possible, without any over-cutting. B.R.S. used an Efficiency Production custom-engineered Shore-Trak™ Sheeting Guide Frame System to shore the 12 x 16 x 20 ft. deep four-sided pit. Kimrey explains that, “The system was not only the best shoring option, it was the only shoring option approved by the DOT.”

Efficiency’s Shore-Trak™ is the industry’s only pre-fabricated, custom-engineered, cross-utility shoring system that integrates seamlessly with Efficiency Production’s Universal Slide Rail System. Efficiency Slide Rail is a component shoring system comprised of steel panels (similar to trench shield sidewalls) and vertical steel posts. Shore-Trak™ Guide Frames can be utilized instead of Slide Rail panels where existing cross-utilities are present.

B.R.S. first needed to cut out the road’s surface to the exact required measurements of the system, 12 x 16 ft. Then after digging out about 30 in. of dirt in the hole, B.R.S. laid in two 12 ft., and two 16 ft. Shore-Trak™ Sheeting Guide Frames square and flush in the open cut. With a 24 in. auger, pilot holes were bored out 6 ft. deep to stand up the Universal Slide Rail System Corner Posts, which have two integrated continuous grooved rails. The outside rails on the posts are slotted, and slid over specially-designed t-tracks on the end of the guide frames that secured the entire system in a 4-sided configuration. Specially-designed internal walers with special tracks on the end were then secured in the “open face” inside rail of the Slide Rail Posts.

“Dig & Push” System actively shores excavation
Twenty ft. lengths of KD-6 sheeting were stood up in the guide frames and overlapped side by side. Then by a process commonly referred to as “dig and push,” the sheeting, guide-frames, posts, and walers were alternatively pushed down to grade as the pit was dug out. Efficiency’s Universal Slide Rail is unique in that it is installed and removed incrementally, which allows the trench to be properly (and actively) shored throughout the entire installation or removal process, always protecting workers from a trench wall collapse.

“The walers really integrated into the corner posts quite nicely,” says Kimrey. “I thought that we would have to weld the walers in place down in the excavation like we’ve done in the past with sheeting, but the Shore-Trak™ System worked much better and eliminated the need for any welding.”

The excavation fit precisely over the 54 in. water main and between two existing parallel utilities: an 8 in. waterline and a 4 in. gas line. Because Shore-Trak™ does not use a vibration machine to work the sheeting down; there is no potential of damaging existing utilities.

The pit was excavated and shored down below the 54 in. water main to 20 ft. with the sheeting panels held up directly over the pipe. B.R.S. then bored a steel casing 40 ft. perpendicular to the water main. Once the casing was pushed up next to the outside of the sheeting, a hole was cut in the sheeting panels to receive the casing and 36 in. ductile iron pipe.

Contractor completes work in record time
Before the tap could be made, B.R.S. needed to coordinate with the city utility about shutting down the water in the existing line. “The DOT promised that the water would be shut off for only 48 hours, so everything had to be done in that time,” says Kimrey. “We cut off the water at 4 a.m., and drained the line for several thousand feet. By 9:30 p.m. that evening, the tap was done and the water was back running through the water main!” Kimrey adds that, “The whole process took only 16 ½ hours, far less than 48 hours. This was record time for us!”

B.R.S. rented the system from Stafford Equipment, a leading construction equipment rental center in the Charlotte area. Stafford provided the on-site installation assistance of Customer Service Representative, Bill Holyfield. “Bill’s Great,” says Kimrey. “I’ve known him for years, and he is just great to work with.” Efficiency Production Slide Rail Manager and Installation Director, Greg Ross, was also on-site to assist B.R.S.

Shore-Trak™ exceeds expectations; meets requirements for future
“The Shor-Trak™ was just a great system, and really worked better than what I expected,” explains Kimrey. “Now that the North Carolina DOT has approved this system as ‘active shoring,’ I expect that we will be able to successfully bid on future DOT let jobs in the state.”

Project engineer praises system
The projects engineer, George Brant, of Mecklenburg Utilities also agrees that the system worked great for this project: “Efficiency’s Shore-Trak™ Sheeting Guide Frame System was ‘made to order’ for this job as it kept the excavation very tight, but didn’t take a lot of time to install, because B.R.S. could simultaneously excavate as the system was installed,” Brant says.

“We have similar conditions on other new projects, and we will consider using the same system again now that we know the DOT has approved it,” adds Brant. “We recognize that it is an excellent product that works well, and we want to get the word out to other contractors that (Efficiency’s Shore-Trak™) Sheeting Guide Frame System is an option for them.”

The ground condition for excavating the pit was actually better then what was expected. It was soft clay, but not wet or saturated. B.R.S. used a CAT 330 excavator with 3 yard bucket to dig the pit and install and remove the sheeting, and Shore-Trak™ Guide Frames and walers. From cutting the pavement to replacing the pavement, the water main tap was completed in just one week during July 2006.

Stafford is a distributor of equipment and supplies for the construction industry, operating from nine locations in Virginia, the Carolinas, and Georgia. Stafford's strong reputation in the construction equipment industry comes from being a leader in providing “quality product lines and excellent service, at all times, at any cost.”

Efficiency Production, Inc., “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 and MIOSHA standards.

The excavation needed to be as tight as possible, without any over-cutting. B.R.S. used an Efficiency Production custom-engineered Shore-Trak™ Sheeting Guide Frame System to shore the 12 x 16 x 20 ft. deep four-sided pit.	Twenty ft. lengths of KD-6 sheeting were stood up in the guide frames and overlapped side by side. Then by a process commonly referred to as “dig and push,” the sheeting, guide-frames, posts, and walers were alternatively pushed down to grade as the pit was dug out.
Efficiency’s Universal Slide Rail/Shore-Trak™ is unique in that it is installed and removed incrementally, which allows the trench to be properly (and actively) shored throughout the entire installation or removal process, always protecting workers from a trench wall collapse.	B.R.S. bored a steel casing 40 ft. perpendicular to the water main, and once the casing was pushed up next to the outside of the sheeting, a hole was cut to receive the casing and 36 in. ductile iron pipe. The water-tap to the 56 in. main took only 16 ½ hours –record time for B.R.S.!