BTrenchless is Tunneling Subcontractor for C470 Corridor Expansion in Denver

September 12, 2018 by NASTT Staff


Project: C470 Managed Lanes
Owner: CDOT
General Contractor: Flatiron / AECOM Joint Venture
Tunneling Subcontractor: BTrenchless (A Division of BT Construction, Inc.)

BTrenchless is the tunneling subcontractor for Flatiron/AECOM Joint Venture for the expansion of the C470 corridor on the South side of the Denver Metro area.

BTrenchless has completed the following drives on this project:

  1. 362 LF of 42” RCP was installed using the Akkerman 420 Tunnel Boring Machine.
  2. 324 LF of 48” RCP was installed using the Akkerman 480 Tunnel Boring Machine.
  3. 387 LF of 72” RCP was installed using the Akkerman 720 Tunnel Boring Machine.
  4. 355 LF of 72” RCP. This storm sewer line is in a redesign phase and will be installed using the Akkerman 720 Tunnel Boring Machine.
  5. 267 LF of 66” RCP. This tunnel is in the final design phase and will be installed using the Akkerman 660 Tunnel Boring Machine.

The main challenges encountered during this project were an abandoned 48” steel waterline and an abandoned 12” AC waterline that were found during our 72” RCP tunnel drive.  We first encountered the 48” steel waterline and had to remove a section of the waterline through the head of the 720 TBM, as we continued the drive another 30 LF, we encountered a 12” AC waterline that had to be abated and removed through the head of the 720 TBM, as well.

Overall, this tunneling project has been a success for all parties involved, despite the challenges that we have encountered.

As always, Morty the Tunnel Rat is on hand to supervise the project!