Research On Surrounding Rock Stability And Supporting Of TBM Excavated Hard Rock Roadway In Coal Mine

In China's highway transportation tunnels,water conservancy tunnels,urban rail transit and other engineering fields,Full-face rock tunneling machine(TBM)has been used widely,the related research and engineering cases of the rock tunnel of the TBM construction vertical mine are rare at home and abroad,due to the geological conditions of the strata in the coal mine and the complicated construction conditions of the coal mine roadway.It is urgent to study the factors affecting the stability of surrounding rock in hard rock roadway under TBM excavation and roadway support scheme,with the popularization of TBM application in hard rock roadway construction.Based on theoretical research and engineering case analysis of deep coal roadway construction in coal mines,selected TBM excavation project in south return airway of a coal mine in Shanxi as background project,using method of theoretical derivation,numerical simulation and on-site monitoring,considering the deeper buried depth of the roadway,the geostress field mainly based on the tectonic stress field,and the characteristics of the TBM tunneling cycle,mainly conducted the following research.Starting from the destruction law of circular roadway under load,derivation a elastoplastic analytical solution of stress field,strain field and plastic zone radius of surrounding rock in circular roadway under non-uniform load,analyze the influence of lateral pressure coefficient on the range of plastic zone.Using background engineering construction roadway as prototype,establishing a numerical simulation model in FLAC3D software,simulated the whole process of TBM tunneling hard rock roadway under different supporting conditions,inferred distribution and evolution of stress field,displacement field and plastic zone of surrounding rock in all supporting conditions under the disturbance of TBM excavation,and optimized the design parameters of the construction site support plan.On-site monitoring in situ in the roadway of background engineering TBM construction,collected the data of the deformation of the surrounding rock of the roadway behind the roadway,the axial force of the anchor bolt and the axial force of the supporting anchor cable,analysis of its changing rules and influencing factors,it shows that the support scheme effectively controls the stability of the surrounding rock of the roadway,verificate the feasibility of the support scheme.Comparative analysis of numerical simulation and on-site monitoring results,the results of the two methods have small errors in value and consistent trends,which verifies the accuracy of numerical simulation.By changing the parameters of the calculation model in the numerical simulation,the influence of the hardness of the rock mass,the section size of the roadway and the angle between the axis of the roadway and the maximum horizontal principal stress on the stability of the surrounding rock of the roadway is discussed.Figure 31 table 5 reference 69...