Transportation Tunnel Rehabilitation

Hundreds of highway and rail transportation tunnels in North America have been rehabilitated in the last two decades. Tunnel rehabilitation is usually dictated by an owner’s need to extend the working life of the structure, but typically has the added benefit of increasing capacity (greater speed or increased clearance) and enhancing safety. Not only has rehabilitation proven to be an economical alternative to new tunneling, but it can be safely accomplished by working during short work “windows” without taking the tunnel out of service. This paper presents methodology for planning and designing of tunnel rehabilitation projects, and case histories illustrate successful excavation and support technologies.