Micro Tunnelling

MICRO TUNNELLING

THE TUNNEL BORING MACHINE IS COMPOSED OF A BORE HEAD EQUIPPED WITH A HYDRAULIC OPERATED CUTTER IN THE FRONT.

Microtunneling is a pit-launched trenchless technique and uses laser-guided controls.
Microtunneling is defined as a remotely-controlled, guided, pipe-jacking operation that 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.
An entry or launch pit is excavated and provided with a jacking system and thrust wall.
Microtunneling is used to install pipelines that cross highways, railway lines, pipelines etc. MTBMs gives a high degree of accuracy compared to other trenchless methods.
MTBMs can be used to bore through all types of soil, sand, clay and even through hard rock. Installation lengths can exceed 225 meters with dia up to 3000 mm.
Even though Microtunneling is a bit more expensive than other trenchless techniques, the accuracy, reliability and lower maintenance cost of pipelines makes it a better choice.

The pipe pusher consisting of hydraulic jacks is used to push the casing installed right behind the Bore Head. The cuttings from the bore head is evacuated from the casing by using the conveyor or Augers installed in smaller casing pipe. Bentonite is also injected in the annulus between the casing and the adjacent pipe to reduce friction while pushing longer drives. After completion of the crossing cement grout can be injected throughout the bore to avoid any settlement.

The bore alignment is continually checked using a laser incorporated into the tunnel bore and steerable hydraulic cylinders makes it possible to make adjustments during the boring process. Moreover, a shield can be installed in the upper part of the tunnel bore, which makes it possible to avoid any excess excavation that might produce subsidence.

TESPL has installed Large Diameter pipes for Water and Sewer Boards as well as for Oil and Gas Pipelines up to a dia of 68” Casing Pipe and lengths up to 100 meters in single shot.

We own a fleet of 7 different Diameter of Bore Heads i.e. 42”, 48”, 54”, 60”, 68”, 72” and 80”.

MTBM FLEET

LIST OF MACHINERY

  • 1000MM MTBM / PIPE JACKING WITH 1200MM SLEEVE.
  • 750MM MTBM / PIPE JACKING WITH 800 & 900 MM SLEEVE.
  • 600MM MTBM / PIPE JACKING.
  • ALL MTBM / PIPE JACKING SLEEVES (MM): 1050, 1200, 1350, 1500, 1800, 2000.