Parallel Thimble Shoal Tunnel Project

Chesapeake Bay Bridge and Tunnel District [CBBT]
Dragados USA / Schiavone Construction
$755 million USD
October 2016 — December 2025
Services performed
Design, checking and Engineer of Record for temporary structures design (trestles, TBM push frame and cradle, muck pits, various shallow and deep foundations)
The Parallel Thimble Shoal Tunnel Project will construct a new two-lane tunnel under Thimble Shoal Channel in Norfolk/Virginia Beach, VA. When complete, the new tunnel will carry two lanes of traffic southbound and the existing tunnel will carry two lanes of traffic northbound.
The tunnel length is approximately one mile, the outer tunnel diameter 42 ft and will be constructed with an EPB tunnel boring machine (TBM). The maximum tunnel depth (crown – at its deepest location (mid-channel)): 105 feet below the water surface. Due to space constraints a variety of complex temporary structures are required, e.g. trestle for TBM delivery.
Holocene marine alluvial deposits (Channel Fill Deposits, Tabb Formation) overlie soil formations of the Pliocene Epoch, Tertiary period (Yorktown Formation).
Norfork, Virginia, USA


  • Construction with extreme space constraints.
  • Excavation works on artificial island (dredged sand).
  • TBM Thrust frame diagonals acting in tension.

Piling works for trestle

Muck pit for excavated material