Mining Institute, Kola Science Center, Russian Academy of Sciences:

Kalashnik A. I., Head of Laboratory, Candidate of Engineering Sciences, e-mail: kalashnik@goi.kolasc.net.ru
Zaporozhets D. V., Leading Engineer
D’yakov A. Yu., Junior Researcher

Kovdorsky Mining-and-Processing Integrated Works:
Kazachkov S. V., Chief Miner
Sokharev V. A., Chief Geologist

Under consideration are approaches to georadar survey for studying structure and condition of rocks in open pit benches. It has been shown that non-disturbing study methods, giving complete (profile) picture of boundary conditions in addition to geological ones, provide actual and detailed information. 8 GPR profiles of 11 km in total length were made, including 7 km for near surface probing (at a depth up to 30 m) and 4 km for deep probing (up to 200 m) in benches of Zhelezny open pit mine. The methods are developed for identification of subsurface structure damages in bench rocks thus allowing increase of the efficient positioning and tracking of damages at significant cost reduction if compared to conventional methods. The detailed analysis of the results of GPR studies for two questionable sites in the open-pit mine is presented; it enables evaluation of geological structure of bench rocks and delineation of zones with different features as well as undetected tectonic faults, dykes, pillars, intrusions and other geological structures at the depth of 200 m. The system analysis of GPR probing together with geological data and geomechanical measurements permits to reveal host rock condition, including formation of zones subparallel to general contour of borrow-cut and having thickness up to 4–5, 10–20 and 20–60 m. These zones are governed by different parameters of stressstrain state, continuity (fracturing) and water saturation of rocks. Based on the studies, the practical guidelines are offered to validate parameters of new benches in the open pit mine under discussion and substantiate engineering solutions of mining on a new apatite–staffelite site.

1. Kasparyan E. V., Kozyrev A.A., Iofis A. B., Makarov A. B. Geomekhanika : uchebnoe posobie (Geomechanics : tutorial). Moscow : Vysshaya shkola, 2006, 503 p.
2. Kozhukhovskiy A. V., Zavyalov A. A., Kozyrev A. A., Seryy S. S., Dunaev V. A. Gornyi Zhurnal – Mining Journal, 2012, No. 10, pp. 29–35.
3. Kalashnik A. I., Demakhin A. Yu., Zaporozhets D. V., Dyakov A. Yu. Issledovaniya primenimosti georadarnogo zondirovaniya dlya otsenki i monitoringa gornotekhnicheskikh konstruktsiy (Researches of application of georadar probing for assessment and monitoring of mine technical constructions). Problemy i tendentsii ratsionalnogo i bezopasnogo osvoeniya georesursov : sbornik dokladov Vserossiyskoy nauchno-tekhnicheskoy konferentsii s mezhdunarodnym uchastiem, posvyashchennyy 50-letiyu Gornogo Instituta Kolskogo Nauchnogo Tsentra Rossiyskoy Akademii Nauk, Apatity (Problems and tendencies of rational and safe mastering of georesources : collection of reports of All-Russian scientific-technical conference with international participation, devoted to the 50-th anniversary of Mining Institute of Kola Science Center of Russian Academy of Sciences, Apatity). Saint Petersburg, 2011, pp. 363–366.
4. Kalashnik A. I., Dyakov A. Yu. Issledovanie vzaimosvyazi raspredeleniya napryazheniy v porodakh ustupov karera s elektromagnitnymi kharakteristikami georadarnogo zondirovaniya (Research of interconnection of distribution of tenses in rocks of benches of open pit with electromagnetic characteristics of georadar probing). Glubokie karery : sbornik nauchnykh trudov Gornogo Instituta Kolskogo Nauchnogo Tsentra Rossiyskoy Akademii Nauk (Deep open pits : collection of scientific proceedings of Mining Institute of Kola Science Center of Russian Academy of Sciences). Saint Petersburg : Renome, 2012, pp. 478–484.
5. Starovoytov A. V. Interpretatsiya radiolokatsionnykh dannykh : uchebnoe posobie (Interpretation of radar data : tutorial). Moscow : Publishing House of Moscow State University, 2008, 192 p.
6. Kalashnik A. I., Kazachkov S. V., Sokharev V. A., Zaporozhets D. V., Dyakov A. Yu. Vestnik Murmanskogo Gosudarstvennogo Tekhnicheskogo Universiteta. Nauchnye trudy Murmanskogo Gosudarstvennogo Tekhnicheskogo Universiteta – Bulletin of Murmansk State Technical University. Scientific proceedings of Murmansk State Technical University, 2013, Vol. 16, No. 1, pp. 93–97.