Historic Underground Tunnel Breakthrough by TBM "Mahavir" at Gandhi Maidan
The Patna Metro Rail Project has achieved a momentous civil engineering milestone. The giant Tunnel Boring Machine (TBM) "Mahavir" has successfully completed its breakthrough at the upcoming Gandhi Maidan underground station box, marking a critical step forward in Corridor-2 construction.
This achievement represents one of the most challenging underground transit operations in Bihar due to the dense urban and historical layers above the tunnel alignment.
Key Details of the Breakthrough
| Parameter | Details |
|---|---|
| Tunnel Boring Machine | TBM Mahavir (DZ1090) |
| Breakthrough Site | Gandhi Maidan Underground Station Box |
| Depth Below Ground | Approximately 22 meters |
| Alignment Section | Corridor-2 (Patna Junction - Akashvani - Gandhi Maidan) |
| Safety Performance | Zero ground settlement recorded |
Overcoming Complex Engineering Challenges
Excavating a subterranean passage beneath the heart of Patna was filled with unique challenges:
- Densely Populated Commercial Zones: TBM "Mahavir" carved through earth directly beneath multi-storey commercial complexes, markets, and historical buildings on Fraser Road and Ashok Rajpath without causing any surface settlement.
- Uninterrupted Traffic: The entire process was completed silently 22 meters below, keeping the busy traffic flow around Gandhi Maidan completely unaffected.
- Alluvial Soil Control: The proximity to the Ganges river meant handling soft, clayey, and sandy soils, requiring precise Earth Pressure Balance (EPB) technology.
Next Steps for the Underground Segment
Following this TBM breakthrough, engineers will shift focus to track installation, overhead traction systems, and architectural finishing of the Gandhi Maidan underground station. Once operational, this section will form the transit backbone of Patna, connecting Patna Junction to major hospitals (PMCH) and educational hubs like Patna University.