Study On Stress And Deformation Regularity Of Tunnel Lining Structure Using Conical Freezing

Conical freezing is a new freezing pipes’ arrangement form associated with rescuing trapped TBM(Tunnel Boring Machine).For rescuing TBM trapped in water bearing loose sandstone,it has incomparable advantage over traditional methods.However,freezing construction will have effect on the stress and deformation of the tunnel and it can not be ignored.This paper studied the stress and deformation regularity of existing tunnel Lining structure while using conical freezing,and it will provide reference for the design and construction of similar projects in the future.Firstly,Through apply anisotropic expansion of frost heaving to analytical solution of single thick-walled cylinder,this paper arrived at the deformation expression of frozen soil’s inner and outer edge which took anisotropic expansion of frost heaving into consideration.By establishing the boundary conditions of displacement,it arrived at the analytical solution of the frost heaving stress which the tunnel suffers from when there is soil between frozen soil and tunnel.Next,this paper gave single factor analysis on anisotropic expansion of frost heaving,frozen-heave factor,elastic modulus of soil and thickness of tunnel.Secondly,the study did the typical parameter calculation,single factor experiment and orthogonal experiment using numerical simulation software.The typical parameter calculation get the temperature field,displacement field and stress field calculation results.Single factor experiment studied how the obliquity of freezing pipe,the outer diameter of tunnel,initial ground temperature and elastic modulus of soil have effect on the stress and deformation of tunnel.The orthogonal experiment studied which factor has the biggest impact on the stress and deformation of tunnel.Finally,This study did the physical simulation experiment.By designing the model using similarity theory and doing the experiment,the study gained the experiment data of the stress field and analyzed the experiment results.By comparing the data of analytical analysis and numerical simulation,the study found that they had same conclusions.Through the qualitative analysis of numerical simulation and physical experiment,the study verified the engineering applicability of the numerical simulation.