European Tunneling Technique Cuts 50 Weeks From Construction Schedule for Brightline Extension
The Brightline high-speed rail extension from West Palm Beach, Florida, to Orlando International Airport (OIA) will use an innovative box-jack system to accelerate the construction timeline of a tunnel from one year to two weeks.
"This is the first time the box-jack system will be used for a train project outside of the Northeast United States," reports Kim Slowey. The construction technique has been implemented once before in the United States, earlier this year on on Long Island Railroad expansion project in New York City.
Here's how Slowey describes the process:
The developer of the box-jacking system, Italian company Petrucco, is using special hydraulic jacks to push two precast concrete boxes — one 146 feet long and the other 126 feet long and both with 42-foot-long sidewalls — under a roadway east of the airport while an excavator digs out a path from inside the box and from the opposite side. Each box weighs more than 3,000 tons, and the installation will take a 40-person crew working 12-hour shifts around the clock.
Granite Construction, the general contractor for a 37-mile stretch of the Brightline extension, says it will consider using the technique for future projects as well.