Microtunneling is a preferred method for the installation of sewer pipelines with a diameter of 250mm to 2500mm, when exact specified inclinations have to be achieved, best suited for gravity sewers. It also allows the pipeline installation along curved trajectories. Suitable pipe materials are steel, ceramic, fiberglass, polymer concrete.
The microtunneling machine is mounted on its track in the launching pit. The machine consists of a boring head, thrusting hydraulic press and a laser directional system, used for steering. The pipeline is installed in sections, one after the other. After the first pipe section is installed the machine travels back to the rear end of its track, a new pipe section is mounted and the boring continues. The boring head is equipped with a cutting shield, which rotates and shreads the soil, while forming a tunnel from the starting to the end pit. The soil, which is transported out through the head and the pipes into the launching pit, is transported out of the pit with an excavator.