- Design-Build delivery of pedestrian tunnel beneath active railroad lines
- Innovative installation of pulling not pushing to keep in-service railroad embankment in compression
- Reinforced concrete box tunnel fabricated on site prior to installation
- Geotechnical instrumentation includes horizontal and vertical inclinometers and prisms surveyed with Automatic Total Station
- A time-lapse video of construction, courtesy of D.A.Collins, can be viewed on our YouTube Channel
Brierley Associates formed a design-build team with regional contractor D.A.Collins Construction to install a pedestrian tunnel through the embankment that supports the main east-west rail corridor of Pan Am Railways and CSX paralleling the Mohawk River in Upstate New York. The pedestrian tunnel connects existing stretches of the Empire State Trail System that traverses from New York City to the Canadian Border via the Hudson River Valley Greenway and Champlain Canalway Trail and from Buffalo to Albany via the Erie Canalway Trail.
Comprised of reinforced concrete, the 107-ft long box tunnel has interior dimensions of 12-ft x12-ft. Fabrication of the box tunnel occurred upon a reinforced concrete launch pad poured perpendicular to the in-service railway embankment. The structural boxes were then pulled through the embankment beneath three railroad lines via steel tendons that were installed through the embankment and connected to hydraulic jacks affixed to the end of the box. On the other side of the embankment, the steel tendons were connected to a steel-sheeted and braced cellular cofferdam.
Brierley Associates provided geotechnical and structural design services, construction consulting, and on-site construction phase engineering services.