Study On The Deformation Test Of Subway Tunnel Based On Optical Fiber Sensing Technology

As an important part of urban transportation system,metro shield tunnel in the security situation in the process of long-term operation high attention by the society,the settlement of subway shield tunnel deformation is one of the core indicators for its safety assessment.The strain and deformation detection of tunnel settlement is an important research area.In the optical fiber sensing technology,the distributed optical fiber sensing technology with its high degree of automation,strong ability to resist electromagnetic interference and the advantages of the distributed detection has become the concern of the engineering researchers new strain and deformation detection technology.In this paper,the application of distributed optical fiber in metro shield tunnel deformation detection has been studied and improved.According to the similar theory,using organic glass and pure aluminum bolt as the model making materials,the subway shield tunnel model was designed and made.And based on the model of tunnel,with the method of model test,the distributed optical fiber compared with resistance strain gauge,dial indicator,the research of distributed optical fiber sensing technology in the settlement of metro tunnel deformation detection is feasible.The main work of this paper is as follows:(1)In this paper,the author studies the relevant literature and materials,and makes a specific study and summary of the types of optical fiber sensing technology and the advantages and disadvantages of their respective applications.Based on the research background,the practical significance of this experiment is clarified.(2)Based on the prototype of metro shield tunneling,the principle derivation method is adopted in the selection of similar theory,and the parameters of metro shield tunnel model are determined.The types of materials suitable for metro shield tunneling model are determined.The design and manufacture of the tube pieces of the subway shield tunneling model are completed,which lays the foundation for the model test.(3)From the layout of distributed optical fiber,optical fiber,optical fiber sensing detecting position calibration system of the building of distributed optical fiber sensing technology in the subway shield tunnel strain and deformation test study on the application.The accuracy of distributed optical fiber strain detection is verified by a comparative analysis of the strain detection results measured by high-precision strain detection methods such as distributed optical fiber and strain gauge.At the same time,the distributed optical fiber strain measurement value is converted into the settlement deformation value and compared with the deformation measurement value of the percentage table to verify the feasibility of the distributed optical fiber settlement deformation detection.(4)The existing strain conversion algorithm for distributed optical fiber sensing technology is derived and analyzed,and the original algorithm is modified.