The Mechanism Of Zonal Disintegration Of Deep Rock Masses

With the quick development of the global economy, the resources every countryneeds increse daily. The mineral resource which lies in the shallow ground can notsatisfy the human needs, thus the mining activity of the world is becoming deeper anddeeper. Due to the high stress of deep rock mass, the mechanism of deformation andfailure is greatly different from the shallow rock mass. In the projects of deep goldenmines in South Africa, the Taimyrskii and Mаяк mines in Russia and Quantai mines inXuzhou of China, experts adopted many physical ways and found that there will bezonal disintegration phenomina of fractured zone and non-fractured zone, which appearalternatively, in the deep rock mass engineering. Such a special mechnical pheneminoncan only happen in the deep rock mass and can not be explained by traditional rockmechanics. Considering the discontinuous and incompatible facial features of deep rockmass, this thesis try to study the mechanism of zonal integnation in deep rock massbased on Non-Euclidean geometry theory. The main researches are as follows:①The non-Euclidean continuum model for the deep intact rock masses isestablished, including plane strain problem under non-hydrostatic pressure conditionand the condition considering effects of the axial in situ stress. When discussing planestrain problem under non-hydrostatic pressure, the original problem can be divided intotwo sub-problems. As result, the total elastic stress-field distributions of the surroundingrock around the deep tunnels subjected to non-hydrostatic pressure can be determined. Itis observed from experiments that the zonal disintegration phenomenon is sensitive tothe axial in-situ stress. A new non-Euclidean model in which effects of the axial in-situstress with arbitrary value on the zonal disintegration phenomenon in the surroundingrock masses around a deep circular tunnel is taken into account is established.②The non-Euclidean continuum model for the deep crack-weakened rock massesunder non-hydrostatic pressure condition is established. This model takes the effects ofcracks on the phenomenon of zonal disintegration of the surrounding rock massesaround deep circular tunnels under non-hydrostatic pressure condition intoconsideration. it is assumed that the rock masses containing a set of parallel cracks isplanar, isotropic, and linear elastic. What’s more, through numerical computations, thelaw of zonal disintegration phenomina is summerized.③A new non-Euclidean model in which effects of the axial in-situ stress with arbitrary value on the zonal disintegration phenomenon in the surrounding rock massesaround a deep circular tunnel is taken into account is established. This is amicromechanics-based, three-dimensional damage model for crack-weakened rockmasses. The conclusion can be got through concrete calculation.Based on the previous researches, Non-Euclidean geometry theory is introducedinto the research of mechanism of zonal integnation in deep rock mass. Non-Euclideanmodels for different conditions are established and further test the adaptability ofnon-Euclidean geometry theory in deep rock masses. This research not only deepens theunderstanding of the mechanism of zonal disintegration of deep rock masses, butanalizies the effects and laws that the parameters of rock mechanics and Non-Euclideangeometry impose on the deep rock masses. The present method is helpful to understandthe failure and deformation of the deep rock mass.