What is Tunneling & Pipe Jacking?
Tunneling includes several trenchless methods used to install large-diameter pipe and utility corridors without major surface disruption. NorthStar supports four primary tunneling methods:
- Slurry TBM: Uses pressurized slurry to support the tunnel face and transport spoil to the surface.
- Microtunneling / MTBM: A remote-controlled, guided system that installs pipe from a launch shaft.
- Pipe Jacking: Pushes pipe behind a shield or TBM with lubrication to reduce friction.
- Auger Boring: Uses a rotating auger inside casing to remove spoil during short bores.
Why Drilling Fluids Are Critical to Tunneling
In soft-ground tunneling, fluid management is critical to keeping the drive stable and moving. Drilling fluids perform several key functions:
- Face support: Helps balance ground and groundwater pressure at the tunnel face.
- Annular lubrication: Reduces friction around the pipe, lowering jacking forces.
- Spoil conditioning: Improves spoil transport and helps keep the cutter head clean.
- Clay balling prevention: Helps prevent sticky clays from building up on tooling.
- Groundwater control: Maintains fluid properties needed for a stable, dry tunnel.
How NorthStar Supports Your Tunneling Project
NorthStar designs tunneling fluid programs around the specific soil, pipe size, drive length, and groundwater conditions of each project from planning through breakthrough.
For pipe jacking, we estimate lubrication volumes to help contractors plan jacking forces accurately. For slurry TBMs, we help set slurry properties and separation plant treatment for efficient operation.
Our products are used on projects ranging from short microtunnels to long large-diameter drives in sands, gravels, silts, clays, and mixed-face ground. We also provide on-site support and bulk supply.
Key Products
Commonly used additives for tunneling fluid systems.
Fluid Programs for Tunneling
NorthStar's Tunnel EDFPs provide pre-project slurry recommendations, annular lubrication estimates, and product requirements based on soil type, pipe size, drive length, and expected jacking forces. Delivered before mobilization, they help contractors price work accurately and arrive prepared for site conditions.