Managers on Bostons $14.6-billion Central Artery/Tunnel project are fixing pesky water problems in the $6.6-billion Interstate 93 tunnel. A thorough inspection of some 2,000 slurry wall panels uncovered 191 defects, which may cost contractors about $6 million to fix. Numerous roof joint and utility conduit leaks are also being tamed as the project nears completion.
The I-93 tunnel is basically a soldier pile/roof girder single wall structure constructed from 16 contracts involving eight contractors or joint ventures. It has 32,000 linear ft of slurry walls; each wall panel may contain two to five steel soldier piles. The 10-year-long project came under scrutiny after a wall panel blew out Sept. 15, 2004, flooding several lanes. All slurry wall panels underwent a nine-month, two-stage investigation. "Weve already paid for the walls and like any defect the contractor must make them good," says Michael P. Lewis, CA/T project director.