Mechanical response of roof rock mass unloading during continuous
mining process in underground mine
mining process in underground mine
(Hunan Key Laboratory of Mineral Resources Exploitation and Hazard Control for Deep Metal Mines,
School of Resources and Safety Engineering, Central South University, Changsha 410083, China)
School of Resources and Safety Engineering, Central South University, Changsha 410083, China)
Abstract: Taking the test stopes during continuous mining induced roof caving of Tongkeng ore-body No.92 as example, the calculation flow of unloading analysis was established. According to the unloading region division method of the affected zone theory, and the deterioration laws of mechanics parameters of unloading rock mass, the continuous mining process in underground mine was analyzed by the software MIDAS/GTS, the mechanical response of roof rock mass unloading was studied, and the differences were analyzed with the conventional simulation. The result shows that the maximum tensile stress, subsidence displacement and equivalent plastic strain of roof rock mass are 1.5 MPa, 20 cm and 1.5% in the unloading analysis, while 1.0 MPa, 13 cm and 0.9% in the conventional analysis. The values of unloading analysis, which are also closer to the actual situation, are greater than those of conventional analysis; the maximum step in continuous mining is 48 m, which shows that the induced treatment of the roof should be carried out after 2 mining steps
Key words: continuous mining; mining-unload rock mass mechanics; mining-unload disturbance region; dynamic mechanical parameters