Evaluation on drainage degree in roof based on AHP-matter element extension model

In order to evaluate the drainage degree of roof of working face scientifically, the elements such as the predicted water inflow and the observed drainage value in working face were analyzed, the evaluation index system of water drainage degree in roof was established and corresponding grade standard of evaluation was divided. AHP was used to evaluate the water drainage degree in roof in 5 working faces with relatively complicated hydrogeological conditions. The evaluation results showed that the water drainage in roof was good, and safe extraction has been realized in the working faces, the actual situation was consistent with the evaluation results. AHP-matter element extension model can be used to evaluate water drainage degree in roof, and used as reference basis for evaluation of the hydrogeological conditions in working face before mining.