Metro tunnel settlement deformation monitoring method based on distributed fiber sensing technology

Abstract

The invention relates to a metro tunnel settlement deformation monitoring method based on a distributed fiber sensing technology. The method includes the following steps: (1) determining the relation between displacement value and bending moment distribution according to a displacement curve approximate differential equation; (2) determining a conversion relation between strain and settlement deformation according to a material dynamic conjugation beam method to find an explicit linear equation between the strain and the settlement deformation; (3) finally considering settlement of control points, distributing settlement of the control points to each monitoring point through equal weighted distribution to finally obtain the settlement value of each monitoring point. Compared with the prior art, the method has the advantages of being better in adaptability, reliable in calculation result and the like.

Description

technical field [0001] The invention relates to a method for monitoring settlement and deformation of a subway tunnel, in particular to a method for monitoring settlement and deformation of a subway tunnel based on distributed optical fiber sensing technology. Background technique [0002] With the development of engineering measurement technology, electronic instrument technology, and information technology, the theory and method of subway tunnel deformation monitoring have also achieved great development. At present, the content of subway monitoring mainly focuses on vertical displacement monitoring (settlement monitoring), horizontal displacement monitoring (displacement monitoring), and convergence monitoring in subway tunnels. The monitoring instruments and technical methods used are different. Among them, automatic monitoring and Multi-sensor fusion is an important direction for the research and development of subway tunnel safety monitoring. At present, the tradition...

AI Technical Summary

Problems solved by technology

At present, the traditional monitoring methods, such as automatic total station, static level and electronic level system, are relatively mature, but these methods have common shortcomings: 1) point-distributed monitoring: such a monitoring method has the advantages of Discrete, key or dangerous positions may be missed, there are monitoring blind spots, and the actual deformation of the subway tunnel cannot be fully grasped; 2) High cost: the traditional monitoring method is relatively slow, generally requires the assistance of professional and technical personnel, and the monitoring efficiency It is relatively low, and the tunnel engineering environment is usually relatively complex, and the instruments and equipment are sensitive to temperature, humidity, electromagnetic field and other environmental factors, and often cause equipment failures due to damp or rusting of the instruments, and the maintenance and operation costs are relatively high; 3) Difficult to achieve long-distance and large-scale monitoring: Tunnel projects are often hundreds of kilometers long, requiring a long distance and a wide range of monitoring areas. For such long-distance and large-scale monitoring objects, traditional point-based monitoring technologies and methods are usually powerless ; 4) Low degree of integration of the system: Usually, various monitoring methods are self-contained and independent of each other, and the degree of integration is not high, which seriously affects the work efficiency of the tunnel monitoring project

As the monitoring distance increases, the cumulative error of the integral data also becomes larger, so for the monitoring point farther from the boundary point, in the integration process, due to the use of a large number of average strain data with errors, so It is bound to cause the calculated results to deviate from the "real situation", and the monitoring results will no longer be reliable. Therefore, the application of the quadratic integration method in the monitoring of long-distance subway tunnel structures will be limited, and a more reasonable method must be found. method to calculate structural deformation values

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