Micro-tunneling (MT) is a trenchless construction method for installing pipelines beneath the surface in a wide range of soil conditions without expensive dewatering systems. It uses slurry to carry the spoils away from the tunnel heading to the main work shaft. Known for its safety benefits, operators do not have to enter the tunnel with this method. It is capable of installing pipes to accurate line and grade tolerances from the drive shaft to the reception shaft.
An especially advantageous method of choice for conditions where pipeline alignment is deep, Micro tunneling uses all of the following features during construction:
Remote controlled – The Micro tunneling Boring Machine (MTBM) is operated from a control panel, normally located on the surface. The system simultaneously installs pipe as spoil is excavated and removed. As mentioned, personnel entry is not required for routine operation.
Guided – The guidance system usually references a laser beam projected on to a target in the MTBM and is capable of installing gravity sewers or other types of pipelines to the required tolerance for line and grade.
Pipe jacking – The process of constructing a pipeline by consecutively pushing pipes and MTBM through the ground using a jacking system for thrust.
Continuously supported – Continuous pressure is provided to the face of the excavation to balance ground water and earth pressures.