GM Microtunnelling, Slurry Microtunnelling Method
 
Slurry Microtunnelling    (Method)                                                          

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.

- Microtunneling requires jacking and reception shafts at the opposite ends of each drive.
- A 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. 
- 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.
- Precise control of line and grade is accomplished using the guidance system and steering jacks to locate and steer the MTBM during a microtunneling drive.

Description of photo here                  Description of photo here       
              


Benefits of Microtunnelling

• No dewatering of entire line required when working below the water table, dewatering only required in boring and receival pits.

• Accurate to line and grade

• Environmentally friendly

• Reduces risk to the safety of workers and the public

• Allows access to areas that aren't accessible via open cut trenching such as under railway lines, buildings, waterways, highways, trees and vegetation

• Reduces reinstatement costs particularly when large depths are required

• Minimises traffic interruptions
 
 



Bookmark and Share