Microtunneling is a trenchless construction method used to install pipelines beneath highways, railroads, runways, harbors, rivers, and environmentally sensitive areas.

Microtunnels are installed using a remote-controlled drilling and pipe-jacking system.  The drilling system provides continuous support to the excavation face by applying mechanical or fluid pressure to balance groundwater and earth pressures.

Support at the excavation face is a key feature of microtunneling, distinguishing it from traditional open-shield pipe-jacking and therefore is a preferred method when tunneling below the groundwater table and in caving soils.

Microtunnels vs Open Cut or Trenching
  • Drill face support lowers risk of caving and settlement of roadways, buildings and adjacent utilities
  • Can be performed in soil and rock
  • Less excavation, so fewer spoils to remove
  • Tunneling activity is independent of weather conditions
  • Higher production rates
Typical Applications
  • Combined Sewer Overflow Systems
  • Sea, lake or river outfall of sewer, water and industrial fluids
  • Road crossings, streets, railways, buildings, airports, parks
  • Desalinization plant water intake tunnels
  • Gas, electricity, cable, and telecommunication networks conduits


Microtunneling at SDTT Altamira Landfall Executed

Why GeoStructures
  • Provide Design-Build Services for Shafts, Microtunnels and Ground Improvement
  • Specialize in large diameter pipe jacking with long drives, resulting in fewer shafts
  • Expert know-how with experience in more than 25 countries
  • Hold World record tunnel lengths for outfall projects
  • Currently fleet of 12 TBMs