REDLINE UNDERPINNING - LESSONS LEARNED

The Redline Underpinning on the Boston Central Artery/Tunnel project was completed in 1999. One of the major challenges was to accommodate the alignment of northbound Interstate I-93 that consists of four highway lane widths, to pass under a two track subway. This paper describes the problems, difficulties and changes that faced the project, the unique solutions employed, the attitude and method of resolving difficulties and a 'lessons learned' assessment.