ABSTRACT
The Montreal Metro Blue Line extension spans 6 km from Saint-Michel to Anjou, featuring a two-track tunnel, five underground stations, and six auxiliary underground structures. Excavated by a 9.7 m diameter Tunnel Boring Machine (TBM), the tunnel is supported by a 350mm thick precast segmental lining system. This paper focuses on the TBM tunnel’s design, including alignment, geological conditions, spaceproofing, segmental lining geometry and fiber reinforced concrete properties, probing and pre-excavation grouting, instrumentation and monitoring. The structural design follows the latest standards, including ACI 533.5R-20, ACI 544.7R-16, and ITA WG-2, ensuring a robust and durable tunnel structure. This project incorporates innovative design, with a side-by-side tunnel configuration without a separating center wall, a first for North American metro systems. This project advances North American transit infrastructure to address geological challenges and ensure durability using design optimization, including tunnel configuration and lining thickness and material selection.
