Union Station

Over a five-year period, InGeo Design played a critical role in supporting major underground excavation and tunnel rehabilitation work along Front Street in downtown Toronto, between Bay and York Streets. As a design subconsultant, we delivered quick-turnaround, implementation focused solutions in one of the city’s busiest infrastructure corridors offering direct access to key personnel to support EllisDon and structural engineers.

This urban project required excavation around and over the active TTC tunnel, in close proximity to aging buildings and complex utility networks. Designs had to be produced quickly, adapted frequently, and coordinated with multiple teams, all while maintaining structural safety and minimizing disruption to downtown operations.

Key Challenges

• Maintaining tunnel integrity across multiple excavation stages
• Accommodating heavy construction and crane loads above existing structures
• Avoiding conflicts with dense and unpredictable utility layouts
• Providing clear connection details to existing buildings
• Ensuring close communication between field and design teams

InGeo’s Role & Scope

• Direct access to key InGeo engineers, enabling real-time decision-making and responsive collaboration
• Detailed structural connection design between shoring systems and adjacent buildings
• Utility coordination, proactively addressing conflicts with water mains, sewers, telecom lines, hydro duct banks, and gas
• Finite element analysis (FEA) of TTC tunnels during staged excavation
• Lateral bracing design and modeling using SAP2000
• Shoring system design: soldier piles & lagging, caisson walls, shotcrete, tiebacks, struts, rakers, and corner braces
• Temporary support systems for tunnel rehabilitation and utility protection
• Traffic decking design at Bay & Front intersection to maintain safe vehicle/pedestrian flow
• Design of a platform for a mobile crane, considering load transfer to underlying structures and utilities
• Design of micropiles to support vertical loading from rakers in constrained spaces
• Load analysis for tunnel structure under mobile cranes and heavy construction equipment
• Field engineering presence for tieback stressing, raker and strut preloading, flat jack testing, column loading, and rapid issue resolution