Mass ground freezing allows jacking of three massive box tunnels under rail tracks leading to Boston’s South Station for the Big Dig. This remains the largest single ground freezing effort in the USA to date.
The Lenox Avenue subway reconstruction project in New York City involves dewatering of a 2,500-foot long subway tunnel section to allow concrete invert replacement. Well installation and dewatering is accomplished within the active tunnel.
Installation of 450 wells through the half-mile long dividing wall of Hillview Reservoir in New York provides the pressure relief on the wall that allows the twin basins to be safely drained and cleaned in turn.
In an unusual application, ground freezing is used to prevent further erosion at an abandoned salt mine in Louisiana that houses 2.1 million gallons of the nation’s Strategic Petroleum Reserve. The freeze is maintained for five years while the oil is pumped out.