Keystone uses a Cat 349 to excavate and set three stacked Efficiency Production manufactured trench boxes to shore the excavation; then set the filtration vault base slab with a 200-ton (181.4 t) Anthony crane.
Recently, contractor Keystone Excavators Inc. was low-bidder to install a heavy precast storm water filtration vault for the city of Dunedin, Fla. The $201,000 vault installation subproject was part of the city’s President Street Drainage Project.
To install the Suntree Technologies manufactured precast vault, Keystone, headquarted in Oldsmar, Fla., needed to deal with a drainage problem all its own. Throughout the project, groundwater in the excavation was an ongoing problem that needed to be managed.
“The strategy was get in, get out; as quickly as possible,” said Paul Strazzula, shoring specialist of shoring equipment distributor Efficiency Shoring & Supply. “Keystone began digging the pit on Tuesday, set three stacked trench boxes, install the vault at grade, then backfilled the hole. They were finished in time on Thursday morning.” Strazzula said.
To manage the ever-present water in the excavation, Keystone employed a 4-in. (10.1 cm) submersible hydraulic pump and then a second, 6-in. (15.2 cm) pump to keep the water manageable in the bottom of the hole. Even though the excavation was never completely dry, Keystone was able to use a 200-ton (181.4 t) Anthony crane to lay the 70,000 lb. (31,751 kg) base slab and 67,000 lb. (30,390.6 kg) riser section.
Keystone used a Cat 349 to excavate a 28 by 16 by 16 ft. (8.5 by 4.9 by 4.9 m) deep pit and set three, stacked 6 by 28 ft. (1.8 by 8.5 m) trench boxes to shore the excavation. The trench boxes were Efficiency Production manufactured HT8 steel trench shields with 8-in. (20.3 cm) sidewalls, rented from Efficiency Shoring & Supply’s Tampa Branch Office. Keystone also rented road plate from Efficiency, which they used to shore off the ends of the pit.
“When we have a tough excavation project to conquer, we choose to use the pros at Efficiency Shoring & Supply, ” said Jeff Truxton, general superintendent, Keystone. “Efficiency has what we need for every application without having to give a months’ notice to get equipment. It’s on the job site when we need it and Efficiency provides the support we need to get the job done,” Truxton said.
Since 1984, Keystone Excavators Inc. has been providing counties, municipalities, developers and individuals with complete site development, underground utility work and roadway construction.
For more information, visit keystoneexcavators.com.
For more information on Efficiency Shoring & Supply, call 800/220-8707 or visit www.efficiencyshoring.com.