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Tunnel Boring

Tunnel Boring

Traditional tunnel boring is a method used for excavating a tunnel using manual excavation and at the same time erecting tunnel support. The use of a tunnel boring machine (TBM) has also been extensively used in the present.

The TBM equipped with a cutting head, an excavation chamber for soil removal, and conveying system to transport the excavated soil away from the cutting face; this process allows for the easy removal of the soil from the cutting head, its transfer to the excavation chamber, and then eventually out of the machine. TBM comprises a circular rotatable cutting head mounted on a cylindrical shield of a similar diameter such that its axis of rotation coincides with the longitudinal axis of the shield. Within the shield, there are means for both feeding the materials to the cutting head and conveying the soil away from it. The soil thus is cut by the cutter bits and passes through apertures in the cutting head to an excavation chamber immediately behind the cutting head, from which it is then removed and discharged out of the machine. The line and grade of the tunnel is controlled by a laser guidance system ensuring a high degree of engineering accuracy. The laser system uses an accurate control point established at the work pit.