Study On Deformation Properties Of Tunnel Surrounding Rock And Support Pamareter Of The Tunnel Embedded In Carbonaceous Slate

Relying on The Third Railway Survey and Design Institute Group Corporation science and technology project,which is the research on mechanism of stratum deformation and deformation control measures the Changsha-Kunming Passenger Dedicated Line tunnel embedded in carbonaceous slate,Xuefeng Mountain3Tunnel is taken as background in this thesis.According to anisotropy of carbonaceous slate and influence of tunnel surrounding rock stability at different rock dip angles, deformation properties of tunnel surrounding rock and the mechanical of supporting structure are studied adopting the method of combinning therotical analysis and numerical simulation.The detailed research result is as follows:(1)Base on the slate mechanical properties, bedding faces and influencing factors of the large deformations of surrounding rocks, Xuefeng Mountain3Tunnel are predicted to occure extrusion and class I of large deformati-on,combined with engineering geology of Xuefeng Mountain.(2)The complex cariable functions are used to derive the stress distribution equations of the hole plate on one-dimension compression. Based on underground stress boundary condition, the stress distribution regularity of the anisotropic surrounding rock is drawed.(3) Using numerical simulation,the stress, deformation and plastic area of the tunnel underground rock in the carbonaceous slate is studied at different rock dip angles.Softening joints has the obvious influences of tunnel surrounding rock stability.The tunnel underground rock occurs the large deformation,because the deformation caculations is larger than the allowances. The deformation under stratum dip30°is the largest,and90°is the smallest. At last,bench method dynamic excavation is the most reasonable excavation methods.(4) Supporting effect of the primary support and grouting reinforcement are analysed with the numerical simulation.Adding the thickness of the primary support and grouting reinforcement can reduce the deformations effevti-vely.However, they can’t improve the forced condition of support system.At the end, the best Support Parameters are support thickness400mm and reinforced region3m.