Shmatovskyi L.D., Tynyna S.V., Ananyeva O.I. How natural stress of rocks in the roadway face impacts on power parameters of process of their destruction

Details
Parent Category: Geo-Technical Mechanics, 2019
Category: Geo-Technical Mechanics, 2019, № 144

Geoteh. meh. 2019, 144, 178-189

https://doi.org/10.15407/geotm2019.144.178

How natural stress of rocks in the roadway face impacts on power parameters of process of their destruction

1Shmatovskyi L.D., 1Tynyna S.V., 1Ananyeva O.I.

1Institute of Geotechnical Mechanics named by N. Poljakov NAS of Ukraine

UDC 622.831:539.3

Language: Russian

Abstract.

With taking into account the fact that today, most of mines develop layers prone to gas-dynamic phenomena, it is necessary to create facilities for safety roadway driving in the prone-to-outburst rocks. Such rocks are sandstones. While driving the roadways by the blast method, outbursts of sandstones and gas occur at the depth of 700 m and more.

The key trend of solving this very important economic and social problem is to develop and design method and facilities, which can effectively prevent rock and gas outbursts.

Basing on the experience of the work, the most effective method allowing preventing the outbursts is driving the roadway by helldiver with no blasts. 

Wide application of this method in the industries is restrained by absence of commercial helldivers capable to work effectively and safely in the complex stressed rocks.

In order to set rational modes for the rocks breaking and choose basic parameters for operating member of machines designed for working in the complex stressed rocks, it is necessary to take into account rate of impact of natural stresses in the face area of the driving roadway on parameters of the rock breaking process.

Researches of the last years show that it is reasonable to calculate process of the rock breaking, for example, by the disk rolling cutters of frontal and tangential action on the basis of reliable correlation between basic parameters of the process and certain indexes of strength of the massif or its resistibility to breaking. This index is presented by index of contact strength, which, as a rule, is determined by the rock samples. However, rock samples taken from the complex stressed rocks lose their natural stress, hence, essentially impacting on dimension of the contact strength.

As a result of the set problem solving, a nonlinear interdependence between stresses, which near-surface layer of the rocks experiences in area where rock-cutting tool impacts on it, stresses of the rock elastic-limit state and natural stresses is established on the basis of energetic strength theory and verified in laboratory and mine conditions. Today, it is included into the formulas of power and energy parameters for disk rolling cutters of frontal and tangential action in the ring-type work member of helldiver. It allowed establishing impact of natural tensions on designed power and energy indexes of the rock breaking by frontal and tangential rolling cutters. On the basis of analysis of the established dependences the following is determined: at the fixed values of the power indexes, step of rock breaking for frontal rolling cutter and height of ledge for tangential rolling cutter should be increased by 1.5-2.0 times with increase of natural stresses in comparison with corresponding values recommended for unstressed rocks. Rate of disk rolling cutter feeding to the stressed rocks face is limited by safe speed of driving, which is within the range of 0.5-1.5 m/hour depending on degree of the rock stress.

Keywords:

mining, outburst hazard, helldiver of ring-type, frontal and tangential rolling cutter

References:

  1.     1.  Poluyansky, S.A., Shmatovskiy, L.D., Strashko, V.A. et al. (1979), “Determination of resistance of naturally strained hard rock massif to destruction by roadheaders”, Gornyy zhurnal, no. 9, pp. 42-44.
  2.     1.  Baron, L.I., Glatman, L.B. and Zagorskiy, S.L. (1969), Razrusheniye gornykh porod prokhodcheskimi kombaynami [Destruction of rocks by roadheaders], Nauka, Moscow, USSR.

About the authors:

Shmatovskyi Leonid Dmytrovych, Candidate of Technical Sciences (Ph. D.), Senior Researcher, Senior Researcher in Department of Elastomeric Component Mechanics in Mining Machines, Institute of Geotechnical Mechanics named by N. Polyakov of National Academy of Science of Ukraine (IGTM NASU), Dnipro, Ukraine

Tynyna Sergii Volodymyrovych, Candidate of Technical Sciences (Ph. D.), Senior Researcher, Senior Researcher in Department of Elastomeric Component Mechanics in Mining Machines, Institute of Geotechnical Mechanics named by N. Polyakov of National Academy of Science of Ukraine (IGTM NASU), Dnipro, Ukraine

Ananyeva Olga Ivanivna, Engineer, Leading Engineer in Department of Elastomeric Component Mechanics in Mining Machines, Institute of Geotechnical Mechanics named by N. Polyakov of National Academy of Science of Ukraine (IGTM NASU), Dnipro, Ukraine