Study On Stability Characteristics Of Cracked Roadway’s Surrounding Rock And Its Controlling Technique In Deep Mine

With the problem of maintaining the cracked surrounding rock stability in deep roadway, on the basis of predecessors’ research, combined with the engineering background "south rail roadway at+211level" of YangMei minmetals zhao partition, this paper integrated application of theoretical analysis, numerical simulation and field measurement to analyze the geological factors and technical factor of the deformation and failure of surrounding rock, and from the perspective of linear softening and its rheological property of surrounding rock, this thesis study the broken mechanics of the deformation and failure of surrounding rock in deep roadway, meanwhile it reveals the general regularity of the deformation and failure of surrounding rock. According to the corresponding control theory of surrounding rock, finally this paper put forward the suitable controlling measures for deep soft and broken surrounding rock. The major contents are as follows:1) Through analyze the impact of the geological and technical factors to the broken surrounding rock deformation and failure, this paper studied various factors which influence on broken surrounding rock instability, it is concluded that initial rock stress state, rock mass physical structure and the geological structure is the dominant factors influencing the cracked surrounding rock instability in deep roadway.2) This paper studied the characteristics and mechanics of deformation and instability of cracked surrounding rock in YangMei minmetals,.The regular that the surrounding rock has the characters of large deformation, deformation rate, long duration, the large damage range and the deformation has obvious time effect are obtained, the manifestation of surrounding rock deformation and failure are largely due to the physical properties of the rock, the stress of surrounding rock, groundwater and the influence of construction technology, etc.3) The thesis analyzed the character of extrusion damage of surrounding rock in deep roadway with Coulomb-Mohr yield criterion, and studied the elastoplastic range and its stress distribution. For plastic stress distribution, it studied that after the strength of rock mass is greater than ultimate strength of rock mass, it will be linearly reduced. It is concluded that in this case the radius of plastic zone of surrounding rock raised30%than the ideal elastic-plastic radius of plastic zone.4) According to the three-axis creep test of samples from south rail roadway, the creep characteristic curves are similar to elastoplastic model curves. Then the Visco elastoplastic model is adopted to study the creep characteristics. The paper analyzed the creep property of the models under the influence of water. It is concluded that creep equation of rock is nonlinear and the rock creep gradually intensified along with the development of the time, the increase of moisture content and seepage5) On the analysis of deformation and failure rules of broken surrounding rock in deep roadway, this paper studied more suitable roadway support theories for overall cracked surrounding rock, and expound the theory of anchorage support as a whole and surrounding rock support volatility balance theory. According to the characteristics of the large deformation of south rail roadway, it put forward the principle of rational support. In addition, using grouting reinforcement principle determines the south rail roadway grouting parameters.6) Based on the research of the rules of deformation and failure to the soft and broken surrounding rock, using UDEC discrete element software simulate the surrounding rock deformation characteristics, stress distribution and displacement variation in south rail lane under the condition of bolt-shotcrete-mesh, bolt-shotcrete-mesh-beam and bolt-grout-mesh-beam, it is concluded that bolt-grout-mesh-beam support scheme is more suitable for deep and broken surrounding rock control.7) The paper studied the key control technique of maintaining cracked surrounding rock stability in deep roadway. With the slow rate of excavation caused by the characteristics of bolt-grout-mesh-beam, then put forward the pouring of supporting technology; For the condition of large areas of cracked surrounding rock broken in south rail lane during the subsequent excavation, it put forward the local strengthening supporting technology, advance small duct supporting technology and optimize grouting construction technology.8) Observed the pressure of south roadway in the support of bolt-grout-mesh-beam and beam, the results showed that the surrounding rock control technique can effectively improve the stability of cracked surrounding rock in deep mine.