Metro and Tunneling Projects

Metro Tunnel Project – Governance Outcomes

Social sustainability initiatives are some of the hardest to measure the full return of investment, with detailed measurement of outcomes typically not within the remit of infrastructure projects.

Tunneling Techniques in Metro Construction

Each tunneling technique incorporates specific construction technologies that adapt to varied geological conditions:

Tunnel Boring Machine (TBM) Method: TBMs use a rotating cutting head that supports continuous tunneling and concurrent lining installation. This closed-face excavation technique limits exposure to groundwater and soil, which is crucial in soft ground. TBM selection often depends on soil hardness and water content; earth pressure balance (EPB) TBMs, for instance, handle soft, water-bearing soils effectively by balancing face pressure to avoid settlements (Constro Facilitator, n.d.).

Safety Measures in Metro Tunneling

Ventilation and Air Quality Control: Systems that provide fresh air circulation help mitigate the accumulation of gases and dust, which is critical in enclosed tunnel environments. Multi-stage ventilation systems, which adjust airflow based on real-time monitoring, are now common in long tunnels (Constro Facilitator, n.d.). Structural Support and Fire Resistance: To ensure tunnel durability, fire-resistant materials like steel-fiber-reinforced concrete are often used. Fire suppression systems and heat-resistant linings help prevent the spread of fires and ensure a controlled evacuation path (The Tunnelling Journal, n.d.). Health Monitoring and PPE: Worker safety is managed with health monitoring systems, especially in confined or high-dust environments. These include CO2 monitors, PPE for respiratory protection, and automated alarms for toxic gas levels, particularly when tunneling through waterlogged or fault-riddled rock formations (MDPI Structure Magazine, n.d.).