White Papers
Hard Rock Tunnel Boring at the Jefferson Barracks Tunnel
The Metropolitan St. Louis Water District’s Project Clear is a 28-year program targeting wastewater capacity throughout St. Louis, MO. The extensive program includes the Jefferson Barracks Tunnel, running parallel to the Mississippi River at 2 m ID and 5,400 m long. A rebuilt Robbins Main Beam TBM began boring but hit challenging conditions about 2,400 m in, including water inflows. A larger 4.1 m Robbins Main Beam machine, launched in 2022, is now completing the remaining 3,050 m in limestone, dolomite, and shale. The TBM is utilizing a high-powered, high breakout torque cutterhead along with enhanced 360-degree probing & grouting capabilities to detect any karst formations.
- A Clean Solution for Renewable Energy: Small Diameter Hydro Tunnels
- Non-Circular Tunnel Boring for Underground Mine Development
- Unprecedented In-Tunnel Diameter Conversion of the Largest Hard Rock TBM in the U.S.
- Hard Rock Tunnel Boring at the Jefferson Barracks Tunnel
- The Next Generation of Mixed Ground Tunnel Boring Machines