Q. Differences between pipe jacking and micro-tunnelling?
Pipe jacking is a general scheme of installation of pipes with a tunnelling shield in front and the pipes are jacked from a jacking pit toa receiving pit. Tunnelling shield for pipe jacking can be mechanical and electrical equipment for conducting the excavation work or itcould be a manual shield for workers going inside the shield to do manual excavation. For microtunneling, it is a type of pipe jacking of small sized non-man-entry pipes that are remotely controlled. Generally there are two general kinds of micro-tunnelling machines:
(ii) Pressurised slurry
Similar to Pressurised slurry TBM, excavated material is transported from excavation face to surface suspended in aslurry.
(iii)Auger machine
Excavated material is transported from excavation face to drive pit by a cased screw auger.