VNIMI’s Ural Division, Yekaterinburg, Russia:

B. T. Ilyasov, Head of Laboratory, Candidate of Engineering Sciences, bt.ilyasov@gmail.com

Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia:

R. V. Kulsaitov, Associate Professor, Candidate of Engineering Sciences

Ural EnergoResource, Magnitogorsk, Russia:

S. S. Neugomonov, Chief Technical Officer, Candidate of Engineering Sciences

Nornickel Technical Services, Saint-Petersburg, Russia:

N. O. Soluyanov, Chief Geomechanic

The article substantiates the relevance of modeling rock bolt support by the finite–discrete element method for calculating stability of underground mine workings. The mechanics of 1D elements implemented in Prorock program is described. For the real conditions of an underground mine, the method for determining the permissible parameters of support is shown, taking into account the influence of the mining area. The parameters of the artificial stress field were found from the numerical simulation of mining using three different schemes. Schemes 2 and 3 showed more realistic and closer to each other results. Scheme 2 is a finite element simulation with an explicit specification in the caving arch model based on empirical calculations. Scheme 3 assumes modeling by the finite–discrete element method. Scheme 1 shows how the use of FEM can lead to an underestimation of the predicted induced stresses when simulating mining with caving. FDEM modeling of mine workings in various conditions made it possible to determine permissive provisions for the use of compound support systems based on self-attaching frictional rock bolts (manufactured by Ural EnergoResource, Magnitogorsk). The conditions for ensuring stability during construction of mine workings in heavily disturbed and fractured rock masses are demonstrated taking into account the influence of the stoping area. The examples show that, in contrast to FEM, the FDEM models can distinguish between the conditions under which a mine working is in the limiting state and under which it fails. Due to this, the stability reserve as a result of the simulation is determined more accurately, which makes it possible to optimize the parameters of mine support systems based on the FDEM simulation. A case-study describes how FDEM-based modeling allows finding conditions for using a more economical method of supporting underground excavations in comparison with the techniques adopted in the mine.
The study was carried out in cooperation with M. V. Kotik, Project Group Manager at Ural EnergoResource, Magnitogorsk, Russia.

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