This part of the tailgate was selected due to impact of
additional stress from unmined left pillar in seam No. 3 and
mining of previous longwall (No. 22 in Fig. 1). Approximately
half of the above-mentioned monitoring section was located
under the unmined pillar in seam No. 3 and the aim of scanning was to reach a complex deformation of this section in the
3D view (slip yokes of steel arches of support, deformation of
ceiling and side arches of steel arch support, swelling of floor
rocks, deformation of middle wooden props, etc.).