| The stability of rock mass is related to the safety and efficiency of all the construction and operation of rock engineering,including mine roadway,transportation,water conservancy,hydropower and other important basic industrial content.The deformation and failure of rock mass in deep roadway is not only related to strength,but also to structural instability.In the field of engineering geology,there is an early saying of rock structure.The classification of rock structure shows that the mechanical response of different rock structures is different.Considering the stability of the tunnel engineering with the structure of the engineering rock mass,it involves the basic concepts and treatment methods of the rock engineering stability,especially for the deep roadway rock engineering.Therefore,it is of great significance to study the bearing characteristics of the different structures of the deep roadway from two aspects of strength and structure.In this paper,the western trackage roadway with a depth of 742 m ~ 877 m in Kou Zi Dong mine,Fuyang Mining Co.,Ltd.is taken as the engineering background.By means of physical model test and numerical calculation analysis,the deformation and failure characteristics and the bearing characteristics of surrounding rock are studied under the same supporting conditions.(1)Taking into account the post peak deformation characteristics of deep roadway surrounding rock,the mechanical tests of 12 samples of about 100 specimens are carried out.A similar material for simulating the deformation and failure process of deep roadway surrounding rock in Kou Zi Dong mine is developed by using sand as aggregate,cement and gypsum as cementing material.Based on the conditions of site geology and engineering,a physical model test of anchorage support for three different types of rock mass,"complete rock mass,layered rock mass and massive rock mass",are designed and carried out.(2)Using Photo Infor V7.2 digital photogrammetry and analysis system developed by the research group independently and the whole process of deformation,failure and evolution of surrounding rock and the induced failure mode of stress/weak surface of intact and layered and massive rock mass under support conditions are obtained.The evolution law of radial stress and tangential stress in different rock mass surrounding rock are analyzed,and the influence law of different rock mass structure on the distribution pattern of main bearing area of tunnel excavation unloading surrounding rock is obtained,and the forming mechanism of pressure arch of different structural surrounding rock is revealed.(3)Establishing the discrete element model of deep tunnel with different structural rock mass through UDEC numerical simulation software.The influence of the thickness of layered rock mass and the dip angle of the massive rock mass on the spatial distribution of the pressure arch of the surrounding rock are studied,and the most unfavorable angle distribution of the surrounding rock is obtained.The criterion of anchorage formation of surrounding rock in deep roadway is put forward,which reveals the influence mechanism of layered rock thickness and lump rock inclination angle on the development and evolution of anchorage pressure arch of surrounding rock in deep roadway. |
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