Author(s): WANG En-yuan, CHEN Peng, LI Zhong-hui, SHEN Rong-xi, XU Jian-kun, ZHU Ya-fei, School of Safety Engineering, China University of Mining & Technology, Key Laboratory of Gas and Fire Control for Coal Mines, Ministry of Education of China, China University of Mining & Technology, School of Safety Engineering, North China Institute of Science and Technology, School of Mines, China University of Mining & Technology
Pages: 2220-2225
Year: 2014 Issue:  11
Journal: Journal of China Coal Society
Keyword:  resisitivity; stress-strain; dilatation; precursory information;
Abstract: In order to study the coal resistivity variation characteristics in deformation and destruction process,the stress,strain and the resistivity of coal during uniaxial compression process were tested using self-built real-time testing system of loaded coal resistivity. Furthermore,the resistivity response rules and variation mechanism at different stages of complete stress-strain were analyzed. The results show that in the process of complete stress-strain of coal mass,the resistivity undergoes the process from descending to ascending,which shows an irregular "V"variation pattern when dilatancy occurs. In the densification and flexibility phases before dilatation occurrence,the variation of resistivity is determined by the closure of coal fissures and stress action. Because of dilatation,the coal resistivity always shows an increasing tendency at the plastic stage. After the peak stress,the coal body enters into a failure stage and the coal resistivity is further improved. Through a real-time monitoring on coal resisitivity,the variation rules of resistivity can be deemed as precursory information so as to reflect the dilatation and sudden change before the coal body reaches a failure,which can provide a new technological mean for forecasting the dynamic disaster of coal and rock.