Optical Inspection with the DMT SlimBoreholeScanner

The DMT SlimBoreholeScanner is a tool for optical inspection and documentation of slim boreholes for structural and geotechnical analysis. It can be pushed by hand into boreholes as small as 1”. Its light weight allows for easy inspection even of upward holes in the roof. Hence it is ideal for the scanning of roof-bolt holes that are drilled regularly in tunneling projects.

When pushed into a borehole, the wall is illuminated by a ring of LEDs. A camera takes 360° images of the borehole wall and stacks them slice by slice giving an image of the complete unwrapped borehole. With this the three dimensional position of dividing planes and their density in the roof of a tunnel can be determined. Frequent scanning of the anchor boreholes gives optimised, absolute and comparable information about loosing zones in the tunnel roof.

The DMT SlimBoreholeScanner is self-contained and powered by internal batteries. All data is stored on internal memory that can be read out directly after logging. The tool is intrinsically safe for use in underground mines. The optional database-, readout- and interpretation software allows an easy handling of huge data amounts and the safety qualification of the rock. With the software it is possible to determine the width of faults semi-automatically. With the data base the current scan can be compared with older ones which allows early recognition and reaction to difficulties while building a tunnel.