Study On Stability And Ageing Mechanical Characteristic Of Deep Mine Rock In The Jinchuan2th Mine Under Water-Rock Interaction

Jinchuan2th Mine has been mined to the level of850meters, its about1000meters to the ground surface. With mining, the deep mining problem was gradually revealed, for example, the roadway section convergence, groundwater, the stability of the upper part of backfill body,they seriously affect the deep mine safety production. Therefore, Jinchuan Group Company set up a science and technology key project for the study of the deep rock mechanics--<Study on the deep rock mechanics under high intensity in Jinchuan2th Mine>-to study the basic mechanical properties application of deep rock uder the dry or water-saturated environment. Basing on science and technology key project, the author has studied the parameter of rock mechanics, the propagation of rock subcritical crack, rock elasto-viscoplastic and the effect of water. The main contents are as follows:(1) According to statisticsing the previous ground stress data, a fitting equation has been given to predict the deep groud stress. According to the existing850-1000m level geological data, the ground stress of850-1000m level was simulated and analyzed; According to the the deep rock mechanics experiment and the deep geological findings, the parameter of deep rock mechanics was given by synthesis of existing rock mechanics parameter values.(2) The cracks of relatively complete surrounding rock in deep tunnels was propagated and coalesced to the damage of tunnels. The marble and granite samples were chosed to study the law of subcritical crack growth under dry and water-saturated environments and effect of water on subcritical crack growth was analyzed. On the basis of the basic theory of fracture mechanics and stress corrosion, a preliminary study of the engineering applications of subcritical crack propagation theory was conducted.(3) The deep roadway section seriously convergences with a strong rheological properties and convergence displacement was affected seriously by water. Therefor the lherzolite and amphibolites rock samples were selected to study its elasto-viscoplastic properties uder the dry or water-saturated environment by rheological test experiments of a circular incremental step load and unload method. The generalized Kelvin model was chosen to simulate rheological properties according to the experimental results, key parameters were obtained and effect of water was analyzed.(4) The Generalized Kelvin model has been improved to simulate the characteristics of rock destruction; Based on Fluid-solid Coupling Theory, the finite element rheological model of rock under the fluid-structure interaction effect was derivated and a theoretical basis was provided for further program development research.(5) The deep tunnel of850m level was simulated by the finite element software-Midas GTS and it’s stability was analyzed. According to the results of analysis, the recommendations were given to choose tunnel position and cross-section shape; the rheological property of deep tunnels cross-section convergence was simulated by Flac3D. According to the simulation results, the various stages of supporting key positions were given. From the stress and the contact surface, the upper backfill was simulated to analyze its stability by the finite element software Midas-GTS.Based on the actual project of Jinchuan2th Mine, the deep typical rock and the deep rock engineering stability has been studied by engineering geological survey, test, the theoretical analysis and numerical analysis. The result of research has important theoretical and practical significance to safety production of Jinchuan2th Mine.