Micro Tunnelling / Pipe Jacking

Micro Tunnelling is a trenchless construction method used to install pipelines beneath highways, railroads, runways, harbours, rivers, and environmentally sensitive areas.  Micro Tunnelling 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 Micro Tunnelling, distinguishing it from traditional open-shield pipe-jacking.  

Micro Tunnelling requires jacking and reception shafts at the opposite ends of each drive. The Pipe Jacking & Micro Tunnelling process is a cyclic pipe jacking operation.  A Micro Tunnel boring machine (MTBM) is pushed into the earth by hydraulic jacks mounted and aligned in the jacking shaft.  The jacks are then retracted and the slurry lines and control cables are disconnected.  A product pipe or casing is lowered into the shaft and inserted between the jacking frame and the MTBM or previously jacked pipe.  Slurry lines and power and control cable connections are made, and the pipe and MTBM are advanced another drive stroke.  This process is repeated until the MTBM reaches the reception shaft.  Upon drive completion, the MTBM and trailing equipment are retrieved and all equipment removed from the pipeline