5250 Yonge Street

InGeo Design was engaged by G Group Development Corporation to deliver excavation shoring design and monitoring services for a 31-storey mixed-use tower located at the southwest corner of Yonge Street and Ellerslie Avenue. The development includes four levels of underground parking constructed directly adjacent to the active TTC subway tunnel.

InGeo developed a soldier pile and lagging system supported by tiebacks and corner braces to support the deep excavation. Given the proximity to sensitive TTC infrastructure, our team conducted a detailed Finite Element Analysis (FEA) to assess the effect of excavation on the subway tunnel, ensuring compliance with TTC developer submission requirements.

We supported the client through the PUCC (Public Utilities Coordination Committee) circulation process and implemented a monitoring program. With fast, coordinated delivery of designs and direct access to experienced engineers, InGeo enabled safe excavation.

Key Challenges

• Excavation adjacent to active TTC subway tunnel
• Meeting TTC developer submission and monitoring requirements
• Deep excavation with complex corner conditions
• Coordination with multiple regulatory stakeholders including PUCC

InGeo’s Role & Scope

• Design of soldier pile and lagging shoring system with tiebacks and corner braces
• Finite Element Analysis to model excavation impacts on TTC subway tunnel
• Support for PUCC utility circulation and permitting
• Installation and monitoring of precision targets inside the subway tunnel
• Full monitoring package including pile, precision, inclinometer, and vibration monitoring
• Pre-construction condition surveys were done all around the site