A statistical approach for the integrated analysis of mine induced seismicity and numerical stress estimates, a case study Part II: evaluation of the relations

摘要

Integrated analyses at a number of underground operations have suggested that qualitative relations may exist between microseismic variable values estimated in real-time from mine seismic systems and the stress estimates provided by numerical models. In this study, multivariate statistical techniques were used to evaluate whether quantitative relations could be formed using data from the Creighton Mine in Sudbury, Ontario. It is believed that if sufficiently reliable relations could be developed, they might then be exploited to better characterize the state of the rock mass and provide insight beyond what could be obtained from either data set in isolation. This insight could then be used to eventually impact both short- and long-term mine design decisions. This paper represents the second part of a two part series and describes the evaluation of the 11 statistically significant relations that were formed in the first paper between variables within the stress and seismic databases. Specifically, the model adequacy and the stability of each relation was evaluated. In addition, the prediction capabilities of each relation were evaluated and the relations were interpreted relative to prior experience and physical theory. The results of this component of the study indicated that all but three of the developed relations met the statistical requirements for relations of this type and all were shown to be quite stable. In terms of prediction, it was demonstrated that this could best be achieved through the application of Discriminant Function Analysis. This technique was shown to be capable of suggesting which events were generated under relatively high-stress conditions, though the technique was less successful at correctly identifying events generated under lower stress conditions. Interpretation focussed on the relation between the stress conditions at the source and two particular variables from the seismic database and concluded that the observed variations in source strength were primarily controlled by spatial variations in confinement. The importance of a rigorous methodology was also discussed, as was potential ways in which the relations of the types formed in this study could impact mine design decisions.