Jingyihuo North Tianshan Deep Analysis Of The Rock Stability

Deep and Long Tunnel stability analysis of rock in the tunnel engineering analysis to explore more and more, in the past has been more research. the geological features of complex high-intensity area Long deep tunnel stability theory and methods is Further explored, to deepen its scope of application, the analysis of general rules of tunnel surrounding rock deformation and support design for the tunnel to provide the necessary information is explore. In this paper, combined with previous studies based on the north of the Tianshan Mountain Crossing Long deep tunnel as an example, the introduction of the tunnel complex on the basis of engineering geological characteristics, the following work is done:(1)import and export of paragraphs rock stability theory by Platts, the stress transfer theory and Terzaghi theories were compared. North Tianshan tunnel by calculating the stability of surrounding rock export, we can see the top of the cave and the wall section by its own mechanical characteristics are not stable, need be supported.(2)the typical cross section of the hole acting to rock in FEM, the model to extract the appropriate boundary conditions, initial stress distribution calculated by simulation of excavation process, and then exert forces, solve and analyze the stress, The re-distribution of strain and deformation of surrounding rock, destruction, and from the mechanics, rock mass failure criterion and the size of the angle of rock deformation to analyze the stability of surrounding rock, compared to conditions in different rock surface surrounding the most negative and stress concentration and make the necessary supporting recommendations. Hou-loading after excavation, the maximum principal stress is vertical stress, generally appear in the vault or invert parts of the site should focus on strengthening support. Minimum principal stress is nearly horizontal stress, the minimum principal stress after excavation near the stress concentration at the wall obviously, the minimum principal stress is seen in the wall corner, the position should be strengthened supported(3) the stability of surrounding rock through holes posture conclusion, local stresses in uniaxial data and experimental data, the whole cross section of tunnel surrounding rock rock burst is analyzed and forecast to determine whether the occurrence of rock burst and the the extent of rock burst, which for the tunnel construction and security post provides more meaningful information.