Rock-mass classification for design of roof supports - a statistical evaluation of parameters.

Principal component analysis and factor analysis were used to evaluate the different groups of interrelated factors, and discriminant analysis was used to determine the relative contribution of the individual variables in differentiating different types of roof conditions. Based on these analyses, five parameters were selected for the classification; namely, spacing of bedding planes, rock strength, weatherability, ground water condition and structural disturbances. Further evaluation of the statistical results enabled the allocation of importance ratings to the parameters. The overall classification was evolved from these statistical studies, and the new system was satisfactorily applied to over 50 actual case studies in India.
Principal component analysis and factor analysis were used to evaluate the different groups of interrelated factors, and discriminant analysis was used to determine the relative contribution of the individual variables in differentiating different types of roof conditions. Based on these analyses, five parameters were selected for the classification; namely, spacing of bedding planes, rock strength, weatherability, ground water condition and structural disturbances. Further evaluation of the statistical results enabled the allocation of importance ratings to the parameters. The overall classification was evolved from these statistical studies, and the new system was satisfactorily applied to over 50 actual case studies in India.