METHOD TO EXPAND TUNNEL Russian patent published in 2014 - IPC E21D9/01 B28D1/08 

FIELD: mining.

SUBSTANCE: method to expand tunnel relates to mining, namely: tunnelling, tunnels or mines with supports or without them; methods or devices for their tunnelling, planning of tunnels or mines with additional drilling and cutting devices. The method includes drilling of boreholes by a stiff tool, formation of ridges by means of serial cutting of both at least two strips and cutting of ridges. Cutting of strips that form ridges and cutting of ridges is done by a diamond rope, which is placed onto a rotary tool and rollers, which are then fixed inside the boreholes drilled previously along the design contour. The rotary tool is fixed at the side opposite to the rollers, afterwards the rotary tool is driven. Boreholes are drilled along the design contour, made of points connected in pairs, at the bottom and top with serial displacement aside by a certain pitch. For cutting of strips they use at least two boreholes arranged at one level or at different levels. For cutting of ridges they use at least two cut strips arranged perpendicularly or at a certain angle to each other.

EFFECT: increased efficiency and safety of works, especially in seismic unstable zones, and preservation of tunnel strength.

6 cl, 12 dwg