Calculation of statistical characteristics of rock strength certificate
Introduction. At risk assessment in problems of mining geomechanics it is necessary to consider statistical characteristics of rock physical parameters variability and interconnection - mean square deviations and coefficients of correlation of these parameters for each engineering-geological element. In calculations of career slopes stability rock strength certificate parameters are used - coupling and internal friction angle. Neglection of mutual correlation between rock strength certificate parameters leads to settlement indicator errors overestimate/understating, while the neglection of the coefficient of stability and geometrical parameters of a slope leads to understating/overestimate of degree of risk. Research aim and methodology. On the basis of the regression analysis the present research aims to consider ways of receiving elements of a correlation matrix for various ways of creating rock strength certificate according to the results of laboratory researches of the samples - at monoaxial compression and stretching and by the one-plane cut method. Results. The formulae necessary to calculate rock strength certificate parameters covariance matrix are introduced in the article. It is established that the way of calculating covariance matrix depends on the applied samples laboratory test method. The examples have shown that the correlation coefficient between coupling and of internal friction coefficient can be of various signs. Scope of results. Values of rock strength certificate parameters statistical characteristics, calculated by the offered technique, can be used to solve rock geomechanics probabilistic problems.