Ground Freezing for Major NY Tunnel Project

January 05, 2022

Keller is the leading ground-freezing expert in the world – a point recently reinforced on Long Island, New York, where the team successfully used the technique to provide excavation support and groundwater control on two shafts for a major tunneling project.

It’s the largest infrastructure program ever in Suffolk County. A 2.6-mile stretch of outfall pipe pumping millions of gallons of treated wastewater under the Great South Bay is being replaced.

The $187 million construction contract was awarded by County officials in May 2018 to a joint venture of OHL, Posillico, and SELI Overseas. Keller was handed the subcontract for temporary excavation support and groundwater control on the tunnel’s launching and receiving shafts.

The plans for the 125ft-deep, 35ft-internal-diameter launch shaft specified ground freezing, in large part due to the amount of space available at the Bergen Point Wastewater Treatment Plant, where the tunnel starts. “It’s a small site, with room for just one rig, so there isn't really space to carry out a diaphragm wall,” says Keller’s Director of Ground Freezing, Joe Sopko.

Joe has almost 40 years of experience with ground freezing and Keller is one of the few companies in North America to offer it. It’s also the only one to carry out its own drilling for the refrigeration pipes and to run its own in-depth analysis and modeling to ensure the highest levels of quality control.