| Based on conformal transformation method of plane elastic complex function,the analytical solution of stress and displacement under the combined action of in-situ stress and hydrostatic pressure is obtained for a deeply buried non-circular pressure tunnel with lining.In this paper,the support delay and the full contact between the surrounding rock-mass and the lining are taken into consideration.Through the surrounding rock and lining stress and displacement continuity conditions an d the inner boundary of the lining stress boundary conditions,using the power series method,will be transformed into the problem of solving linear equations.Calculating the specific expressions of three groups of analytic functions by FORTRAN programming.In the rock without supporting the corresponding unit circle outside the analytic function;surrounding rock in support under the action of the corresponding outside the unit circle of analytic function;surrounding rock lining after lining ring of the corresponding analytic function.Then the stress and displacement in the surrounding rock and lining are obtained.Taking horseshoe hole as an example,the tangential normal stress,radial stress and shear stress of surrounding rock boundary and lining inside and outside boundary are calculated under different lateral pressure coefficient,different displacement release coefficient and different internal water pressure.It is found that the effect of displacement release coefficient and internal water pressure on the stress of lining and surrounding rock should be considered according to the actual working conditions.Under normal working conditions,when the internal water pressure is relatively small,it is possible to postpone the support when constructing the tunnel,so as to reduce the tangential normal stress of the lining.When the water pressure is large,the tunnel should be supported ahead of time,so as to prevent the boundary from pulling.In this paper,the example is simulated and analyzed by using the finite element software ANSYS.Tangential stress,radial stress and shear stress numerical solutions of rock boundary,lining inner and outer boundary for horseshoe shaped examples are obtained.At the same time,the analytical solutions are verified by numerical results and the results are in good agreement.The theoretical derivation of this paper is correct and the theoretical basis for the correctness of the numerical solution is also provided. |
