RANK Research Center–Mine Design Institute, Kemerovo, Russia:

M. V. Lysenko, Deputy Director of Science and Innovation, limak2@yandex.ru
A. S. Pozolotin, Director, Candidate of Engineering Sciences
A. V. Aikin, Head of Study and Innovation Department

Aikhal Mining and Processing Plant, ALROSA, Aikhal, Russia:

O. A. Nikolenko, Head of Department

The study subject is the geomechanical behavior of boundary and reinforcement at junctions of underground excavations in difficult geological conditions of the Aikhal Mine, Aikhal Mining and Processing Plant, ALROSA. The study aims to improve stability of mine junctions by introducing the reinforcement technology with multifunction cable bolts AK01-25. The mining conditions in the Aikhal Mine are complicated by permafrost. In the course of heading, permafrost thaw results in unpredictable rockfalls. In connection with this, it was decided to undertake field trials of new reinforcement technologies for mine junctions. The trials were implemented in accordance with the developed engineering documents on reinforcement of junctions by multifunction cable bolts with regard to permafrost thaw for the effective life of an underground excavation. In December 2016 the junction of a ramp on level +60 m and a rehandling room to level +53 m was reinforced with multifunction cable bolts AK01-25. The base plates were represented by crown runners PGK15 and PGK15A. To monitor roof rock displacements, in the center of the junction, deep-seated benchmark RGZ was installed. Monitoring has been performed continuously since December 2016, and no displacements in the roof rocks have been recorded. The reinforcement technology with multifunction cable bolts in the wide-span junction reduces material expenses, specific content of metal and labor input of cable bolting, moreover, it enhances occupational safety owing to higher quality reinforcement and elimination of possible roof rockfalls.
The authors appreciate participation of P. Yu. Koveshnikov, Deputy Head of Department, Mirny Mining and Processing Plant, Mirny, Russia, in this study.

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