Research On The Application Of Construction Monitoring And Nondestructive Testing Technology In A Highway Tunnel

Tunnels can overcome complex terrain and optimize the route of expressways.They are more common in expressway engineering.Among them,shallow-buried,biased and small-distance tunnels are a typical representative.New Austrian Tunneling Method is currently a commonly used technology in tunnel construction.In recent years,construction monitoring and measurement technology has developed rapidly,and various non-destructive testing technical solutions and equipment have emerged.How to determine an effective monitoring and measurement technical solution combined with the actual needs of a large number of actual projects is crucial to ensure the safety of tunnel construction and the quality of the project.In this paper,a shallow-buried,biased,small-distance tunnel of a certain expressway is the research object,and the practical application of tunnel construction monitoring and measurement and non-destructive testing technology is studied through the method of combining theoretical numerical simulation and field monitoring and measurement.In view of the specific situation of the construction of the shallow-buried,unsymmetrical,small-distance tunnel,which is based on the project,the double-side pilot method is adopted.Through the use of numerical simulation methods,on-site monitoring and measurement technology and non-destructive testing methods,the surrounding rock deformation at each construction stage The situation and force conditions were analyzed,and the surrounding rock deformation law was found.On this basis,the dynamic monitoring and measurement plan combining tunnel construction monitoring measurement and non-destructive testing was demonstrated and determined and applied in actual construction.The main research contents and results of this paper are as follows:(1)By consulting various data,monitoring and measuring the construction of shallow-buried and biased small-distance tunnels(observation inside and outside the tunnel,surface settlement,vault subsidence,peripheral convergence,etc.),advanced geological prediction(geological radar method)and anchoring quality of bolts The non-destructive testing and other monitoring measurement or detection methods are summarized,and the principles and methods of the current tunnel construction monitoring measurement methods are discussed,which provide a basis for determining the finite element numerical simulation analysis model and actual construction monitoring measurement plan in this paper.(2)Based on the finite element numerical simulation method of tunnel engineering,a three-dimensional finite element analysis model was established for the project of this article,namely,a shallow-buried,biased,small clear distance tunnel of an expressway.Analyzing the deformation of surrounding rock and the stress of surrounding rock during construction,the deformation laws of surface settlement and vault settlement of the target section of the shallow-buried,unsymmetrical pressure and small-distance tunnel are obtained,that is,the final settlement form of the tunnel surface It is a "W" shape with a small left and a large right;the settlement stage of the tunnel is characterized by a slow deformation period,a rapid deformation period and a stable period.The settlement deformation curves of the left and right tunnel vaults are basically the same,and the settlement deformation curves of the unilateral tunnel vault and arch abutment are also basically the same.Both have a slow deformation period,a rapid deformation period and a stable period;the pilot pit opens under the tunnel.Excavation is a stage of rapid vertical deformation of the surrounding rock of the tunnel,and it is necessary to further strengthen monitoring,measurement and support during the construction stage.By comparing the vertical deformation and horizontal deformation of the tunnel,it is concluded that the shallow-buried,unsymmetrical,small-distance tunnel is mainly vertical deformation.The results of finite element numerical analysis show that the deformation of surrounding rock and the stress value of surrounding rock are both within the safe construction range.On the basis of the above-mentioned finite element numerical simulation and analysis results,the technical plan of this article relying on engineering construction monitoring and measurement is determined.Compared with the general engineering projects that use experience and qualitative methods,the method of this article is more pertinent.The construction safety of the biased small clear distance tunnel is of great significance.(3)The field monitoring and measurement data carried out for the actual project in this paper show that the actual measurement results and the tunnel surrounding rock deformation law obtained by numerical simulation are basically the same;the advanced geological prediction results indirectly verify the rationality of the finite element analysis model established in this paper;The non-destructive testing of anchor rods can quickly and efficiently check the quality of anchor rod support,which is of great significance for ensuring the safety and reliability of tunnel construction.(4)Engineering practice shows that the monitoring and measurement program that combines finite element numerical simulation,on-site monitoring and measurement and non-destructive testing used in this article is effective in the application of this project.Construction monitoring and measurement and ensuring the safety of tunnel construction have played a major role.The tunnel finally passed the acceptance test and further verified the reliability of the technical methods and related research results in this paper.