Description
Road tunnel fire and life safety is an ever-evolving field, driven by the goal of improving occupant safety in fire emergencies. The newest fire and life safety innovation of note is the full tunnel length pressurized egress corridor.
Notably, various highway tunnel projects in the United States, including the Midtown Tunnel (Virginia), Hampton Roads Bridge-Tunnel, and Alaskan Way Viaduct Replacement, have, in recent years, incorporated independently pressurized evacuation routes. This trend transcends the United States and includes tunnels such as the Channel Tunnel (UK), the Burnley Tunnel (Australia), and the Mont Blanc Tunnel (France and Italy). The trend is growing and expanding, as illustrated by the proposed Fraser River Tunnel in Vancouver, BC, where a pressurized route that combines an egress corridor and a multi-use path is planned.
This paper discusses the pressurization of protected long egress routes, including the calculation and implementation of construction-related joint leakage. These systems are crucial for a tunnel’s overall fire and life safety by providing smoke-free egress routes that are separated from the roadway and protected from the direct effects of fire and traffic. The discussion includes the historical development of these corridors, their benefits, challenges, and potential optimization strategies.
This paper also explores design considerations for egress corridor pressurization systems, including criteria such as pressure differentials, door air velocities, and the number of open doors, all aimed at maintaining a smoke-free egress route. Special attention is given to the impact of construction-related joint leakage on pressure profiles and the feasibility of installation. Collaborative efforts with clients and first responders, along with design services during construction, help ensure that the final product is optimized and functions as intended.
