Geomechanical Model of Underground Mine. Part I. Creation

The article describes stages of  geomechanical modeling  of  a mine. The geomechanical model is based on the frame model of  the  structural  geology  of  a  deposit.  The latter model is created by integration of  information  acquired  at  different  stages  of  the  deposit  exploration  and  operation:  data  bases  on exploration coring, geological plans and profiles. 

Aiming to fill the blocky structural geology model with geomechanical information, the program of data acquisition on jointing and properties of ore and enclosing rocks was implemented. The program involved determination of jointing density from the core material and orientation of the joint systems from scanning of the rock mechanics survey borehole walls. Additional data were obtained from jointing surveys in mine workings. It is shown that different tools and technologies of the initial structural data acquisition for the geomechanical model complement one the other. The statistical laws of distribution of the joint length and spacing are obtained. The collected structural data are used to calculate the rock mass quality index by N. Barton. It is found that the calculated Q-indexes agree with the standard rock mass stability categories in the Russian mining practice. 

The blocky geomechanical model is created by interpolation of Q-index within the limits of identified geomechanical domains. The interpolation was accomplished by the method of radial basic functions using a structural trend with direction governed by the morphology of geological bodies composing the rock mass. The resultant rock mass quality index was calculated from the standard indicator estimation procedure. In order to check the interpolation validity in the blocky model, the actual geomechanical data obtained per intervals in boreholes were compared with the relevant interpolated values, and the average initial data were matched with the interpolated values in different directions. Using the created blocky geomechanical model, zoning of the Novo-Shirokino mine field was carried out by the stability categories based on the rock mass quality index. 

Article is available in Russian only.