Tunneling
Deploying advanced Tunnel Boring Machines (TBMs), Sequential Excavation Methods (SEM), and microtunneling in complex soft ground and hard rock conditions.
Bringing knowledge and foresight to every project
TBM Drive Execution
Operating pressurized Slurry and Earth Pressure Balance (EPB) TBMs for large-diameter transit and utility tunnels under water bodies.
Sequential Excavation Method (SEM / NATM)
Mining cavern cross-passages, station vaults, and complex tunnel intersections using fiber-reinforced shotcrete and lattice girders.
Ground Freezing & Soil Grouting
Stabilizing water-bearing soils using liquid nitrogen ground freezing and jet grouting to prevent surface settlement.
Precast Segmental Liners
Fabricating and installing gasketed steel-fiber reinforced concrete segments to ensure 100-year watertight tunnel lining.
Project spotlight: DC Water Clean Rivers First Street Tunnel
SNS Construction bored a 2.7-mile, 23-foot diameter deep rock tunnel beneath Washington, D.C., reducing combined sewer overflows by over 98% and protecting regional waterways.
Partnering today to build the underground networks of tomorrow
Constructing over 150 miles of complex transportation, water, and utility tunnels globally.
