Development Of Optical Fiber Bragg Dislocation Meter And Research On Visualization Monitoring System Matching

The long longitudinal section of utility tunnel will inevitably cause partial differential settlement,which will cause pipeline rupture,fire and even explosion.In this regard,it is very important to obtain the partial differential settlement information of the utility tunnel corridor in time and accurately.As an excellent sensing element,fiber Bragg grating(FBG)can perceive the change of external strain and temperature through the change of central wavelength.It has the advantages of small volume,high sensitivity,anti electromagnetic interference and quasi distribution.It is suitable for monitoring utility tunnel.In addition,Revit provids a friendly port support for building a three-dimensional visualization monitoring platform as a platform for building information.In this paper,three kinds of dislocation gauges have been developed with FBG as the core sensing element,and three matching dimensional visualization monitoring plug-ins have been developed.The work completed is as follows:(1)The basic structure and theory of FBG are introduced;A FBG strain and temperature sensing model is established;The temperature compensation method and sensor calibration method of FBG are put forward.(2)A large range of rectangular double spring FBG dislocation meter,a large range wedge-shaped FBG dislocation meter and a high precision FBG dislocation meter have been developed.The working principle of three kinds of dislocation meter is analyzed and the light-displacement equation is given.(3)The calibration experiments of a large range of rectangular double spring FBG dislocation meter,a large range wedge-shaped FBG dislocation meter and a high precision FBG dislocation meter were carried out.The displacement-wavelength variation curves and strain-wavelength curves of three kinds of dislocation meters are obtained,the static characteristics of sensors are given,and the error analysis of three kinds of fiber grating dislocation meters is carried out.(4)A three-dimensional visualization monitoring plug-in based on Revit platform is developed,Integrating the basic functions of the SM-130 demodulator,and The design intention and implementation method of the three modules interface and function of the plug-in are described in detail.Then the usability and stability of the plug-in is verified by experiments.In this study,three kinds of FBG dislocations based on the spring structure and the cantilever beam structure are designed Innovatively.The three kinds of dislocation gauges have the advantages of simple structure,obvious transmission way,accuracy of monitoring,adjustable range,and anti electromagnetic interference.It provides a new sensing device for long-term monitoring of relative settlement on both sides of the settlement joint in utility tunnel structure.The range of the large range rectangular double spring FBG dislocation meter is ± 200mm,the bi-directional sensitivity coefficients are 34.85pm/cm and 31.48pm/cm,respectively,the bi-directional static error is 6.077%and 5.776%,respectively.The range of the large range wedge-shaped FBG dislocation meter is ±225mm,the sensitivity coefficient is 23pm/cm,the static error is 3.547%.The range of the high precision FBG dislocation meter is ±22.5mm,the sensitivity coefficient is 23.96pm/mm,the static error is 3.987%.In addition,the 3D visualization monitoring plug-in based on the Revit platform is developed by author.The test shows that the plug-in and the dislocation meter can work in a stable and cooperative way.