| 1725 200th St SE Building C, Suite 200 Bothell, WA 98021 Phone: 425-205-4930 |
Microtunneling |
Microtunneling requires jacking and reception shafts at the opposite ends of each drive. It does not require routine personnel entry into the tunnel. The microtunneling process is a cyclic pipe jacking operation. The microtunnel 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.
Microtunneling is a trenchless construction method used to install pipelines beneath highways, railroads, runways, harbors, rivers, and environmentally sensitive areas. Microtunneling is defined as a remotely-controlled, guided, pipe-jacking operation which provides continuous support to the excavation face. Continuous face support through the application of mechanical or fluid pressure to balance groundwater and earth pressures is what distinguishes microtunneling from traditional open-shield pipe-jacking.
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.
