Musk's Company Talks Tunnel Project Near Stadium

Safe-T-Shore Assists With Shaw Air Force Base Job

Fri September 02, 2005 - Southeast Edition
James A. McRay



Understanding and implementing strict federal accounting and management procedures on government utility projects can be a challenge for some contractors.

But Chandler Construction Services Inc., headquartered in Ninety Six, SC, has answered the challenge for more than three decades. With an extensive history of providing United States taxpayers with quality construction services, Bob Gettys, construction supervisor of Chandler Construction Services, is proud of the company’s work.

“We continually strive to exceed the military’s expectations for quality, safety and production,” he said.

Working for the Federal Government

Chandler Construction Services is a subcontractor installing a $3-million wastewater treatment plant pump station with effluent force main on Shaw Air Force Base (AFB) in Sumter, SC. Chandler is subcontracting for Webco Construction Company out of Northern Virginia, who was the low bidder on the project let by the Navy’s Resident Officer in Charge of Construction (ROICC) — its office for all construction projects in the Southeast.

Webco Construction understands the additional protocols of the federal government because all they bid is federal government projects.

“It can be very intimidating if you’ve never worked on a federal government project before,” said Nate Engle, Webco’s project manager of the treatment plant. “I’ve been very impressed with Chandler’s work and their flexibility and willingness to follow the guidelines given them when sometimes they don’t understand why the military’s engineers want things done a certain way.”

Pump Station and Effluent Force Main Upgrade

The ROICC’s civilian construction manager and engineer of the project, Gerald Pearson, works mostly in facility construction, and he said this underground utility project was new for him, but he is very pleased with the progress of upgrades being made to the waste water treatment plant.

The new pump station is necessary due to increased volume at the treatment plant, which is located just off the AFB. The pump station will replace the current effluent force main. However, the 18- ft. wide, 26-ft. long, 22-ft. tall pour-in-place concrete pump station will be hooking in the adjacent existing 24-in. DIP effluent pipe before pumping the wastewater through 30,000 ft. of new 12-in. High Density Polyethylene (HDPE) pipe west to the discharge point along the Wateree River.

Limited Space Creates Shoring Challenge

The pump station is being installed in a plot of land with very limited space, tucked between railroad tracks and an intersection of two roads. Telephone poles are also present in the vicinity. These cramped quarters pose several challenges for the excavation. A trench could not be sloped due to the proximity of the road and railroad tracks. Normally, Chandler workers would sheet pile the excavation, however the close space made it impossible to bring in the required equipment such as a crane and sheet driver. Also, the railroad company that owns the land would not allow the vibrations associated with sheeting so close to the tracks.

MSP Rents Offers Solution

Needing another solution to shore the excavation, Chandler contacted Robbie Belk at MSP Rents in Charlotte, NC, who arranged for the rental of a Safe-T-Shore Multibay Slide Rail System.

Safe-T-Shore, a trench shield and shoring manufacturer headquartered in Chandler, AZ, designed and engineered a custom shoring system to fit in the tight quarters between roads and railroad track using its Slide Rail System.

Safe-T-Shore’s Slide Rail is a component system comprised of steel panels and posts. The system is installed simultaneously as the trench or pit is excavated by pushing the posts and panels down to grade as the pit is dug; a process commonly referred to as a “dig and push” system.

The stackable panels slide into rails in the posts, either a double or triple rail, depending on needed depth. In a “multi-bay” configuration (which is being used by Chandler for this project) 1 ft.-wide parallel beams slide into the inside of linear posts and pin-in-place standard trench shield spreader pipes as cross members.

To install the Slide Rail System, Chandler Construction began by cutting a 4 ft. pilot trench and installing an 8-by-24 ft. panel into the outside rail of a 24 ft. tall double-rail corner post, and then added a second corner post to the other side of the panel to construct the short side of the pit. After this, two 8-by-20 ft. panels were slid into the corner posts’ rails perpendicular to the first panel, and two 24 ft. linear posts slid onto the ends of these.

To complete the first bay, 1-by-7 ft. parallel beams with spreader collars were slid onto a rail on the inside of the two linear posts, and three 22-ft. long spreader pipes were pinned-in-place as cross members. Four ft. tall panels were stacked on the 8-ft. tall panels in the outer rail; then 8-ft. tall panels were slid into the inside rails between the corner posts and linear posts on the three shored sides. The bay was then excavated down to a grade of 20 ft.

To install the second bay, this process was repeated with 8-by-14 ft. panels added to the other side of the linear posts, and two more corner posts added to the ends of these panels. Finally, a second 8-by-24 ft. panel was added between the corner posts, completing the entire pit’s opposite short side.

Again, 4-ft. tall panels were stacked in the outside rail and 8-ft. tall panels were slid down the inside rail between linear and corner posts on the three shored sides, and excavated down to the 20-ft. grade. The total inside dimension of the two-bay configuration was 24.5 by 35 ft. 1.5 in.

The pump station pit was excavated in very wet (Type-C) soil conditions, and the site needed to be dewatered for a week before beginning excavation.

Pleased With the Results

Gettys, who has worked for Chandler Construction for more than 20 years, had used Slide Rail before, so he was familiar with the intricacies to installing the non-traditional shoring system.

“Slide Rail really was the best shoring solution for the existing site conditions,” he said.

The installation of the pump station and wastewater treatment plant upgrade began May 22, 2003, and the entire project is expected to be completed Feb. 16, 2006.

Equipment used on this project included:

• Caterpillar 345 trackhoe

• Komatsu 228 trackhoe

• two Caterpillar rubber-tire backhoes

• XU-50 mini-excavator

• Caterpillar IT-28 front loader

• Caterpillar motorgrader

• Thompson and Godwin well point pumps

• T655 large trencher, and a Vermer small trencher

• a 10-wheel dump truck, a flatbed dump truck and a Peterbuilt water truck.

About the Company

Founded as Chandler Utility Contractors by Hubert T. Chandler in 1967, Chandler Construction Services Inc. now employs more than 70 workers and has successfully completed more than 500 projects ranging from industrial facilities to wastewater treatment plants located throughout Georgia, North Carolina and South Carolina. Chandler is an active member of the Carolinas Association of General Contractors (CAGC) and three times has been awarded the prestigious CAGC Pinnacle Award identifying “the best of the best” in the construction industry.

(James A. McRay is Safe-T-Shore’s marketing and media manager.) CEG