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MHD CA/T I-90 / I-93 Jacked Tunnel

Job Highlights:

  • World Record:
    Largest Jacked Tunnel Box
  • SPTC (Slurry) Wall
    314,000 sf
  • Earth/Clay Excavation
    440,000 cy
  • Cast-in-place concrete
    280,000 cy
  • Reinforcing Steel
    42,000 tons
  • Structural Steel Bracing
    61,000 tons
  • Utility Relocation Total
    24,000 lf

This Roadheader was lowered into the jacked box pit in order to
excavate the rock hard, frozen soil underneath South Station.

Joint Venture - Slattery/Interbeton/J.F. White/Perini

On January 15, 1997, the Massachusetts Highway Department awarded the I-93/I-90 Interchange contract to the joint venture of Slattery, Interbeton, J. F. White, and Perini. This project is in the very heart of the Central Artery / Tunnel project. The six-year venture was estimated at $395,207,252.

This ground-breaking contract is best described as three distinct areas of construction: three jacked box tunnels and the jacking of them under the railroad tracks at South Station; construction of extensive ramps, boat sections and tunnels; and finally, the erection of two miles of precast viaducts. The jacked box tunnel completed on December 10, 1999, is still the largest such tunnel ever constructed. The project necessitated soil stabilization through a process known as “ground freezing”. This allowed the project to continue underneath live train tracks in the heart of downtown Boston at South Station.

Needless to say, this project featured an unprecedented amount of traffic congestion management. Once again, J. F. White has proven itself one of the foremost contractors for work in and around the CA/T Project.