The Parallel Thimble Shoal Tunnel Project in Virginia, US currently includes the following elements of design and construction:
- approximately 1,740 m of two-lane tunnel connecting previously constructed parallel bridges with a channel depth of 20.42 m plus 0.91 m of over-dredge in addition to 3.05 m of cover over the tunnel. The procurement will allow for both bored and immersed tube tunnel options;
- widening of Portal Islands n.1 and 2 to accommodate the new tunnel and associated ventilation buildings, as required;
- trestle extension spans from the existing wye-areas to the expanded portal islands with approximately 548.64 m of 2-lane spans and approximately 121.92 m of 3-lane spans;
- approximately 396.24 m of two 3.66 m-wide lanes of at-grade and depressed southbound roadway on both Portal Island n.1 and 2 providing connection between the trestle extension spans and the tunnel portals. Additionally on Portal Island n.1 shall be a 3.66 m-wide right-hand deceleration lane providing for vehicular traffic entrance onto Portal Island n.1.
Additional project elements include: tunnel finishes, tunnel ventilation, tunnel lighting, tunnel emergency egress, approach lighting, electric primary and secondary power distribution system, emergency generators, tunnel drainage system, fire alarm and detection system, fire protection system, lightning protection, communication systems, intrusion detection and alarm system, Supervisory Control and Data Acquisition System (SCADA), Intelligent Transportation System (ITS), traffic monitoring and control devices, island maintenance roadways, and as-needed utility modifications and upgrades.
The project will use Federal funds. For further information about the project visit www.cbbt.com/parallelthimbletunneloverview.html. Click us/121 for tunnelbuilder archive. 15/15.
