Micro-tunneling technology is used to construct an accurate subsurface installation of product pipe (Reinforced Concrete Jacking and Steel Casing pipes). It is an approved worldwide technology as the utmost effective and safest methodology in the field of utility construction industry and preferred over traditional open-cut approach not only under highways but also in the populated urban areas.

The micro-tunneling system consists of a remotely controlled tunneling machine. This system excavates a circular tunnel or borehole into which the product pipeline is installed. Pipes to be installed are connected to the back of the micro-tunneling shield. As the shield forms the bore, it is pushed forward by a set of hydraulic jacks positioned in the Launching shaft and guided by a railing frame, however, when a full length of product pipe is jacked into the ground, new pipes are positioned into the frame, jointed to the pipe string and then pushed forward. This process will continue until the micro-tunneling machine arrives at the reception shaft.

To convey the cuttings soil, water and bentonite mixture is used into the slurry at the cutting face. This slurry is then discharged to the surface through hydraulic lines located inside the carrier pipes. The soil is processed in a settlement tank, where the solid particles are separated and removed; the recycled effluent is pumped back to the cutting face. The slurry system is also used to balance earth pressure and to prevent the influx of groundwater at the tunnel face.

Micro-tunneling is the most advanced subsurface pipe installation technique for constructing pipelines by means of a remotely controlled tunneling shield.