LLC “Institute “Gipronikel”, Saint Petersburg, Russia:

A. V. Trofimov, Head of a Center of Physical and Mechanical Researches, e-mail: AVTro@nikel.spb.su
O. V. Vilchinskaya, Second Category Engineer
K. E. Breus, Third Category Engineer
I. V. Amosov, Junior Researcher

Processes of interaction with rocks are the basis of modern high-capacity mining and metallurgical production. Economic efficiency and industrial safety are decreased due to the design decision-making in the time of ensuring of rock massif steadiness and optimization of mineral breaking and grinding processes to the required coarseness, based on relevant rock properties data. The paper presents the comprehensive approach, used in investigation of physical and mechanical properties of rocks, including the following operations: preliminary analysis of geological documentation of the researched object; development of geomechanically proved sampling method; formation of composition and amount of the test complexes; scientific supervision of sampling; carrying out of comprehensive physical and mechanical tests. There are given the examples of rock mechanics application. Urgent methods, used in experiments, are considered together with modern measuring devices, testing equipment, instruments for certain parameters’ registration, and software for further processing. Methods and means for rock strain measuring are detaily described. Special attention is paid to the correlation of the Protodyakonov hardness coefficient with strength and deformation properties of rocks. Analysis, based on the large volume of statistics data, was carried out during the comprehensive researches. Dependences of the hardness coefficient on the rock strength and stress properties were defined together with correlation coefficients. On the basis of analysis results, there was made a conclusion that correlation of hardness coefficient with cohesion factor and deformation modulus is found to be the best one. At the same time, correlation of hardness coefficient and uniaxial compressive strength turns out to be a dependency, characterized by wide scatter and low convergence, which causes the problem of “f” calculation.

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2. GOST 21153.8–88. Porody gornye. Metod opredeleniya predela prochnosti pri obemnom szhatii (State Standard 21153.8–88. Rocks. Method of definition of breaking point in the time of triaxial compression). (in Russian).
3. GOST 21153.5–88. Porody gornye. Metod opredeleniya predela prochnosti pri sreze so szhatiem (State Standard 21153.5–88. Rocks. Method of definition of breaking point in the time of compression cut). (in Russian).
4. ASTM D 5607–08. Standard Test Method for Performing Laboratory Direct Shear Strength Tests of Rock Specimens Under Constant Normal Force.
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6. GOST 28985–91. Porody gornye. Metod opredeleniya deformatsionnykh kharakteristik pri odnoosnom szhatii (State Standard 28985–91. Rocks. Method of definition of deformation characteristics in the time of unaxial compression). (in Russian).
7. Baron L. I. Koeffitsienty kreposti gornykh rabot (Hardness coefficients of mining). Moscow : Nauka, 1972. 176 p.
8. Protodyakonov M. M. Opredelenie koeffitsienta kreposti krepkikh gornykh porod metodom tolcheniya (Definition of hard rock hardness coefficient by milling). Nauchno koordinatsionnoe soveshchanie po issledovaniyam fiziko-mekhanicheskikh svoystv gornykh porod primenitelno k zadacham gornogo davleniya : tezisy dokladov (Scientific coordination meeting on researches of physical and mechanical properties of rocks, as applied to the rock pressure tasks : thesis of reports). Moscow, 1961.
9. GOST 21153.1–75. Porody gornye. Metod opredeleniya koeffitsienta kreposti po Protodyakonovu (State Standard 21153.1–75. Rocks. Protodyakonov method of definition of hardness coefficient). (in Russian).