HomeProjectsTwin Box Tunnels Through Railroad Embankment

Twin Box Tunnels Through Railroad Embankment

Liberty University, Lynchburg, VA

Project At-a-Glance

  • Design/Build construction of tunnels under active rail lines
  • Innovative installation of pulling not pushing to keep rail embankment in compression
  • Twin box tunnels
  • Four travel lanes are conveyed through the completed tunnel


  • Best Small Project Award”, ENR Mid-Atlantic Region, 2014
  • Best Project Safety Award”, ENR Mid-Atlantic Region, 2014
  • Grand Award”, ACEC Virginia Engineering Excellence winner, November 2014
  • View the time-lapse video of tunnel construction

Project Narrative

This project, designed and managed by Brierley Associates with assistance from Elwyn & Palmer Consulting Engineers, PLLC, is located on the campus of Liberty University on Regents Parkway north of the intersection with Williams Stadium road on the west side of the campus. A unique box tunnel pulling method designed by Brierley was implemented by Southland Contracting, Inc. to successfully install the twin 130-ft long two-lane vehicular tunnels beneath three active Norfolk Southern railway lines that carry about 30 trains each day.

Now complete, these tunnels provide ingress and egress to and from Liberty University at the intersection of Ward Road and Harvard Street. Elements of this project include installation of temporary excavation support systems for the launching and receiving areas; geotechnical instrumentation to monitor ground deformations; spiling to control ground loss at the heading and mitigate deformation of the railways; conduits through the embankment to protect post-tensioning tendons. Construction elements included: a reinforced concrete launching pad; a reaction block and a stable working surface at the receiving area; two, 130-ft long two-lane concrete tunnel boxes, including a cutting shield, at the launching area; and jacking the two tunnel boxes to the final location.

Jacking of the North Tunnel was completed in December 2013 and the South Tunnel was completed in January 2014.

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