Analysis Of Goaf Instability And Evaluation Of Goaf Stability Based On Entropy Theory

:The goaf stability is influenced by many kinds of factors, and their relationships are quite complex. Based on the national "12th Five-Year" technological support program about mined-out3D laser scanning spatial information modeling and dynamic monitoring technology research (2012BAK09B02-05) and the big three-dimensional boundary detection and dilution and loss control technology of large-scale blasting stope research projects, goaf instability is analyzed based on the entropy theory and goaf stability is evaluated by numerical analysis with reference to the actual operation of Fankou Lead-Zinc Mine, The study is aimed to reveal the goaf instability in a new way and develop a method fit for the mine goaf stability classification and evaluation. And provide technical back-up for the mine goaf safety management and goaf instability control.The main research results obtained by the paper are as follows:(1)The dissipative structure of the instability process is revealed. The rule that system entropy is equal to the sum of safety entropy and negative entropy is found. The relationship between the system entropy and the goaf stability is summarized.(2)On the basis of revealing the mechanism of instability of mined-out area, goaf stability evaluation system is established. Aiming at fankou lead-zinc mine, in order to determine the weight of each factor, Analytical Hierarchy Process is applied.(3)The goaf stability classification standard is calculated by using connection entropy method, based on the weight and classification of each factor. The Sh-280mN0-1, Sh-400mS12and Sh-600mN6#S are to be evaluated gob areas. After acquiring their parameter values, their connection entropys are calculated. Their grades are judged by comparing their connection entropys with the goaf stability classification standard.(4)In order to verify the evaluation results whether match actual condition, Fast Lagrangian Analysis of Continua in3dimensions software and Cavity Monitoring System are used. They respectively from the perspective of theoretical analysis and actual measurement demonstrate the evaluation results. Verification results show that connection entropy method is effective to evaluate stability of goaf. Besides, the method is simple and easy to operate.