Middlebury Tunnel

ECI’s Client: Kubricky Construction Corp

Completion Date: 2020

ECI’s Trenchless Technologies Division was subcontracted by Kubricky Construction Corp, the General Contractor of the Middlebury Bridge and Rail Project to bore three drainage tunnels. In the course of 12 weeks our crew used the Tunnel Boring Machine (TBM) to drill through 442 feet of bedrock and mixed ground including soil, rock and sticky clay. Our Civil and Heavy Civil Divisions were also subcontracted to work on the railroad work.

VTrans in collaboration with the Town of Middlebury replaced two nearly 100 year old rail bridges at the center of Middlebury with a 360-foot-long precast tunnel, updated water, sewer and stormwater drainage infrastructure, lowered 3,500 feet of the rail line 4 feet, and built a newly landscaped park between the locations of the former bridges. ECI was hired to bore three drainage tunnels as part of the Early Work Package 3, a contract that included the drainage system, in 2018 along with some additional work while we were on site.

Work began in April with installing a receiving pit for a new stormwater system. ECI hired a subcontractor to blast a 38-feet-deep by 40-feet-diameter drilled shaft to house the stormwater system receiving pit. This part of the project took about 3 months to complete. We were then ready to bore the three drainage tunnels. The first 5 foot diameter tunnel extended 160 feet out to the Otter Creek. The second bore was a 152 foot journey under Main Street to Receiving Pit 2. The third bore was 139 feet long to receiving pit 3 and was completed in October of 2018. It took our crew a total of 12 weeks and each drive was successfully bored under strict line and grade requirements using a motorized small boring machine.

Once the tunnels were bored our teams when to work installing the drainage systems. The Trenchless Technologies scope of work was completed in 2019 and our Civil and Heavy Civil Divisions continued working on the next phase of the railroad tunnel construction which was completed in 2020. This work consisted of removing old rail and install new CRW and ties, install sheet pile SOE, build precast block walls on each end of the tunnel, pour CIP cap walls and relocate water and sewer lines.

Article from the Vermont Rail System about the opening of the Middlebury Tunnel

https://vrs.us.com/improving-quality-of-life-in-middlebury-vermont-the-middlebury-tunnel-opening/

Video from VTrans from the grand opening: https://www.youtube.com/watch?v=PVMCABlpYLE