Shotcrete for Tunnel Final Lining – Design and Construction Considerations

Synopsis:

The use of shotcrete for tunnel final linings has gained increased popularity on a national and international basis. The high quality of the shotcrete material, flexibility in application and workability, as well as the ability to adapt to complex tunnel geometries have contributed to this popularity. When evaluating if shotcrete should be utilized as the final tunnel lining, several aspects should be carefully evaluated to determine the final product’s quality and durability, as well as cost and construction schedule implications for a given tunnel configuration. Among others, geometric complexity, tunnel length and size, staging of a multi-layered application, finish requirements and type of waterproofing will play a major role in the decision. This paper establishes and discusses aspects and criteria that should be considered in the evaluation process for, or against, a tunnel final shotcrete lining. This discussion is supported using recent case histories, in particular the Pedestrian Walkback Tunnel at Washington Dulles International Airport in Dulles, Virginia, and the Weehawken Tunnels in New Jersey for New Jersey Transit to demonstrate the decision process.

Shotcrete for Tunnel Final Linings – Design and Construction Considerations
2004 North American Tunneling Conference Proceedings
April 17-22, 2004
Atlanta, Georgia