Evaluation of top coal cavability based on PCA-FDA model

Abstract

In order to evaluate top coal cavability reasonably, and determine whether coal seam is suitable for top-coal caving.The top coal cavability evaluation model (PCA-FDA) was established by combining principal component analysis(PCA) and Fisher discrimination analysis(FDA).Six influential factors were selected as sample variances for top coal cavability evaluation including the coal seam depth, uniaxial compressive strength of coal, coal thickness of seam folder gangue layer, thickness of coal seam, the development degree of the coal seam joint and fractures and coefficient of direct top filling.PCA was used to eliminate overlapping information in the variables, thus four principal components are extracted as the discriminant factors of FDA.FDA is applied to learn and train measured data of 23 top-coal caving mining face in China.Meanwhile, back substitution estimation method was adopted to verify the model effect, and accuracy is very high up to 91.30%.Finally the established evaluation model was applied in two engineering projects in Shan'xi province, and results show that this evaluation method is scientific, reasonable and reliable.The model can provide a scientific reference for evaluation of top coal cavability and technology parameters selection in top coal caving.

Keywords

• top coal cavability
• evaluation
• principal component analysis
• fisher discrimination analysis