Completed in late 2019, the second phase of the Kosciuszko Bridge replacement project on the east end of Long Island in New York City served as a major leap forward for regional commuters. The bridge is a key element of the Brooklyn Queens Expressway (BQE), an integral part of I-278, and one of the few north-south routes in the area.
Originally constructed in the 1930s, the old Kosciuszko Bridge was the only crossing of Newtown Creek that was not a drawbridge. In the 75-plus years since its opening, traffic had grown exponentially. At the same time, the structure itself had aged and become functionally obsolete. Plans to upgrade this 1.1-mile portion of the BQE had been under serious consideration for 20 years.
When it came to formwork for concrete construction on the bridge, the contractor for the project—Granite Construction—turned to PERI to deliver formwork solutions that would drive efficiency while keeping construction crews safe.
From Pier to Deck
Granite Construction used two PERI RCS (rail climbing system) climbers to build the H-Pylon with two separate upper stems for the second bridge. Rising roughly 216 ft from the ground surface, each pylon was built on a foundation of four 7-ft-diam. drilled shaft caissons extending 160 to 180 ft to bedrock.
To form the hollow rectangular pylon stems (about 20 ft by 11 ft at the bottom and about 15 ft by 10 ft at the top), PERI supplied a combination of its VARIO formwork and MAXIMO wall forming system. The contractor opted to pre-assemble the formwork on site. Both the internal and external formwork systems were then adjusted with each advance, easily changing their shapes to match the profile required for the next concrete placement.
Alternating back and forth between the two towers, the contractor placed the concrete in 18 units per side. Although PERI’s rail climbing system can be advanced using self-contained hydraulic lifts, the contractor in this case opted to use the crane instead to move the formwork from one level to the next. The forming system was designed to be completely tieless, enabling the contractor to significantly reduce its labor and patching costs for the project.
PERI RCS combines the advantages of different climbing systems in a modular system and is used as climbing formwork as well as a climbing protection panel. Through the rail-guided climbing, the climbing unit is securely connected to the structure under construction at all times, which makes the climbing procedure fast and safe, even in windy conditions.
PERI’s VARIO GT 24 girder wall formwork can be adapted to suit all geometries and requirements, including tie positions or acceptable fresh concrete pressure. The system is used as project formwork in residential and industrial construction and for bridge abutments.
PERI’s MAXIMO utilizes the company’s MX tie technology with one-sided tie installation that greatly accelerates forming operations. MAXIMO is significantly faster than conventional panel formwork despite the lower site personnel requirements. The solution’s single-sided anchor configuration requires only one person to operate the equipment, driving overall efficiency on a project.
If You Can Make It There…
Former New York Governor Andrew Cuomo joined other city and state officials to dedicate the Brooklyn-bound span of the Kosciuszko Bridge in the summer of 2019. At the time, the governor said that thanks to the new span, delays on that stretch of the BQE would drop by as much as 65%.
The original article can be found at: Road & Bridge