How Pro-Tec’s Slide Rail Shoring System is used as an economical alternative to tight sheeting has been aptly demonstrated on an Anderzack-Pitzen Construction Co. job in Toledo, OH, where a 34-ft. (10.4 m) long, 10-ft. (3 m) diameter separator tank was installed underground for the Teledyne Company.
To accommodate the tank, a large pit measuring 40-ft. long, 16-ft. wide, and 22-ft. deep (12.2 m long, 5 m wide, 6. 7 m deep) was excavated in unstable, high moisture content ground conditions.
A 30-in. (76. 2 cm) diameter concrete storm sewer pipe in close proximity to the pit precluded side sloping. And spreader pipe used for cross-bracing in standard trench shielding would interfere with placement of the tank, so this method was ruled out.
At first, it looked like the only way to go was to install tight sheeting around the perimeter of the excavation, according to Mike Anderzack, president of Anderzack-Pitzen.
“Figuring the equipment we would need, materials, labor costs and the time factor, no matter how hard we crunched the numbers, there was no way we were going to come in under budget using tight sheeting,” Anderzack said.
Enter the Slide Rail Shoring System
“Over the years, we have worked with the Pro-Tec Equipment people out of Charlotte, MI, whenever trench shielding equipment was involved so I called them to explore any other possibilities, and together we came up with a system that gave us what we were looking for at considerable savings in materials and time,” he explained.
The Anderzack-Pitzen firm used a Cat 345BL hydraulic excavator with a 3-cu.-yd. (2.3 cu m) dipper as its main digging tool, a Krupp 150-ton (135 t) capacity truck crane for tank lifting and placing, and a John Deere 644G wheel loader used primarily for backfilling although both the excavator and loader came in handy to lift and move individual beams, panels and corner posts that make up the slide rail system.
Installing the slide rail system went as smoothly and quickly as the firm had hoped it would. Sixteen panels were used, each 4.5-in. (11.4 cm) thick; four 20-ft. (6.1 m) long corner posts; four 20-ft. (6.1 m) long spreader posts; two 16-ft. (5 m) long, 12-in. (30.5 cm) thick spreader beams; and two 40-ft. (12.2 m) long, 36-in. (91 cm) wide walers.
After the excavation had begun, one panel, a corner post, and another panel were set in place to form a right angle. A second corner post and panel were set in place, forming a “U” shape. Spreader posts between additional panels, and two additional corner posts shored up the perimeter of the 40-ft. (12.2 m) long by 16-ft. (5 m) wide pit. As the excavation was deepened, a second panel, pushed in place on the inside track of the corner and five spreader posts, was installed above the lower panels.
Spreader cross beams were used during installation but were removed after 40-ft. (12.2 m) long, 3-ft. (.9 m) wide walers were attached at ground level to the outside of the spreader and corner posts on both sides of the pit to end up with a clear expanse to accommodate the 34-ft. (10.4 m) long tank.
A concrete ballast pad was poured covering the bottom of the pit. The Krupp truck crane lifted and placed the 38,000-lb. (17,236 kg) tank without incident.
“The amount of time we saved was probably the biggest factor,” Anderzack said.
“We saved about a week. We dug the pit and set up the slide rail system in a day and a half. After the ballast pad was poured, we set the separator, backfilled and dismantled the entire slide rail system in one day. And we had on-the job consulting from Pro-Tec Equipment,” he added.
For more information, call 800/292-1225.
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