Definition - What does Microtunnel Shield mean?
A microtunnel shield is a a boring machine with a closed shield that uses a slurry system for spoil removal. It is used for the installation of sewer pipes and tunnels beneath roads, waterways and railways. The equipment includes a remote control board, a jacking and lubrication system, a slurry system and ancillary equipment.
A microtunnel shield is also known as a microtunnel boring machine.
Trenchlesspedia explains Microtunnel Shield
The use of remote control in the microtunnel shield keeps workers out of harm’s way and provides instantaneous feedback to the operator during tunneling operations. Onboard systems provide for the interpretation of sensors at the cutter head and synchronization of the jacking system with the excavation rate of the microtunnel shield.
The slurry system evacuates spoil from the face of the shield and returns it to the surface, where the evacuated soil is removed and the slurry is recycled back into the system. A second function of the slurry system is to counterbalance groundwater and earth pressures.
MIcrotunneling is a favored method in the trenchless construction industry. Microtunnel shields perform well in a variety of soil conditions. Jacking pipe sections may range from 4 to 40-feet in length, with a pipe diameter of 6 to 120-inches.