Recently, Miami Beach-based contractor David Mancini & Sons, Inc. (DMSI) was low-bidder to install two heavy precast pump station vaults for their hometown City of Miami Beach, Florida. The vaults were installed at 14th and 10th streets.
In 1965, Richard Mancini, incorporated Ric-Man Construction, Inc., which specialized in the construction of large diameter pipelines for municipal sewer and water projects. In October 2010, Richard’s son, David Mancini, incorporated DMSI and now runs the company with his sons.
This Design-Build project consists of installing two new storm water pump stations for the city. Each pump station consisted of a diversion box, dissipater box, wet well, grate box, three junction boxes, drainage defender box, 72-inch reinforced concrete pipe, 60-inch reinforced concrete pipe, four Flygt CP 3501 pumps, tideflex valves and all associated mechanical piping.
The South Florida, the ground conditions for the excavations were extremely wet, and DMSI needed to install a large series of well points to get the soil as dry as possible. The poor soil condition also made shoring the excavation rather tricky as well.
“The strategy was get in, set the precast vault pieces, and then get out as quickly as possible,” said Orlando Castelblanco, Shoring Specialist for shoring equipment distributor Efficiency Shoring & Supply. “And despite needing to trouble shoot the excavation and shoring system installation around the well points, both pump stations were installed on time and on budget.”
Taking a New Approach
The key to managing the quick turnaround for the utility install was choosing the best shoring system for the job. Rather than trench boxes or sloping or sheeting, DMSI went with a shoring system that was new for them; an Efficiency Production manufactured Slide Rail System, rented and supported by Efficiency Shoring & Supply’s Miami Branch Office.
With Florida Branch Offices in Miami, Orlando, Tampa; Texas Branch Offices in Houston and Dallas/Ft. Worth; and a Branch Office in Chicago; Efficiency Shoring & Supply is an official Efficiency Production, Inc. factory-direct sales and rentals company. Efficiency Production provides the widest selection of standard and custom trench shielding and shoring systems. Their versatile products are designed specifically for safe and cost effective installation of utility systems and infrastructure improvements. All products are PE certified to meet OSHA standards.
“After speaking with Efficiency Shoring, we decided to give the Slide Rail system a shot,” said DMSI’s Christopher Lazzari. “We were used to using sheeting on jobs like this but found the Slide Rail to be more cost efficient.”
The Universal Slide Rail is a component shoring system comprised of steel panels (similar to trench shield sidewalls) and vertical steel posts. The highly versatile system can be used in a variety of configurations. It can be configured into small four-sided pits; an obstruction-free ClearSpan configuration; or in a Multi-Bay configuration to install large tanks and structures, or lengths of pipe over 40 feet.
Slide Rail is considered “positive shoring.” It is installed by sliding the panels into integrated rails on the posts, and then pushing the panels and posts incrementally down to grade as the pit is dug; a process commonly referred to as a “dig and push” shoring system. “That’s another advantage of our Slide Rail; there’s no over-excavation,” said Castelblanco. “The system keeps constant pressure against the surrounding dirt, which was critical for the saturated soil DMSI was digging in.”
Obtaining More Space
DMSI rented from Efficiency Shoring & Supply a two-bay, Four-Sided Multi-Bay Configuration, which provides a larger unobstructed area for installing tanks, vaults, and other structures. DMSI’s system was 18-feet-wide, 29-feet-long and 20-feet-deep; and was installed with a Caterpillar 345 Excavator. A crane was used to install the vault base and the two 27 by 16 by 10 feet vault sections and cap. To address fall protection, Efficiency Shoring also supplied a set of 10-feet-wide guard rails, which integrate seamlessly onto the top of the Slide Rail panels.
Multi-Bay utilizes Efficiency’s exclusive Parallel Beams that roll up and down the slotted rail on the inside face of the linear posts and have spreader collars—like trench shield sidewalls—which pin standard trench box spreaders. For the DMSI project, tie-back waler i-beams were added at the top of the Slide Rail System on both of the long sides, attached into integrated waler brackets that connect into a slotted rail on the outside face of the linear posts. Paired with a “sacrificial member” such as a spreader pipe or timber beam braced cross-trench against the bottom of the linear posts, the entire parallel beam spreader assembly can be removed, which provided Mancini with the full 29 feet of open space.
The Right Support
DMSI was impressed with the support they received from Efficiency Shoring & Supply.
“Overall, the support we received from Efficiency Shoring was excellent,” adds Lazzari. “We were provided with an onsite installer plus Orlando and Branch Manager Brian Campbell also made stops to the site.”
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