- Hartford Bridge Street Bridge Replacement
- AllSun Solar Tracker Installations
- CCTA Downtown Transit Center
- Renewable Energy Project – Vermont National Guard 2.2MW Solar Project
- Ryegate Culvert Design-Build Replacement Project
- East Alburgh Bridge Swing Span Automation
- Whipline Gas Bore
- Gentes Road Bridge Rehabilitation
- Renewable Energy Project – Rock of Ages 100kW Wind Turbine
- Lime Kiln Substation Retaining Wall
- North Hero-Grand Isle Draw Bridge Emergency Superstructure Repairs
- City of Burlington Municipal Paving Contract
- Interstate 91 Rutfill Project
- Pinkham Notch Conduit System
- Grade Crossing at Rte 142 Vernon
- Bellows Falls Tunnel Clearance Improvements
- Burlington Tunnel Emergency Repairs
- VELCO 115kV Underground Electric Transmission Line
- VELCO & GMP Lime Kiln Substations
- VTrans Intelligent Information System (ITS)
- Vermont State Archive Fire Water Storage System
Burlington Tunnel Emergency Repairs
ECI’s Client: New England Central Railroad
Completion Date: December 2008
Subcontractors: Boscardin Consulting Services
ECI was engaged by the NECR to perform emergency stabilization of the Burlington Tunnel (located under North Avenue in Burlington, VT). A sudden loss of structural integrity of the tunnel floor caused significant ground movements and longitudinal cracking at the spring-line of the 150-year-old brick lined tunnel. The railroad immediately stabilized the tunnel by flooding the unstable areas concrete. ECI was called in to design/build a permanent repair. The design consisted of a concrete bearing curb on each side of the tunnel with a reinforced concrete track structure (steel cross ties and rebar encased in concrete) to serve as a cross strut to resist the lateral earth pressures. Our scope of work included:
Scope of Work:
- Evaluation of tunnel: cored through brick lining to evaluate crack depth and tunnel lining thickness, installed survey monitoring points and crack monitors; evaluated lateral earth pressures; designed permanent bracing
- Removal of the temporary concrete fill (which was higher than the proposed finish floor elevation) in segments and replacing with new concrete segments.
- Installation of the reinforced concrete curbs to act as a bearing for lateral forces transferred through the track structure.
- Installation and alignment of the steel cross-ties and rail.
- Grouting of cracks with a neat cement grout under low pressures.
The project is also described in a technical paper published and presented at the 2011 Rapid Excavation & Tunneling Conference in San Francisco.