Method for detecting shape change of metro tunnel section

Abstract

The invention relates to a method for detecting shape change of a metro tunnel section. The method comprises the following steps: with a center line of a tunnel track as an original point, establishing a rectangular coordinate system of the metro tunnel section; according to an angle meter, a laser ranger and a laser scanner, performing data measurement on the tunnel section to obtain a coordinate offset angle alpha and coordinates of all measuring points of the metro tunnel section in the rectangular coordinate system, wherein the coordinates of an ith measuring point is (xi, yi); by an elliptic fitting algorithm, performing curve fitting on basic measurement data to obtain a shape parameter, meeting an error requirement, of the tunnel section; judging whether the offset between the shape parameter of the tunnel section and a historical shape parameter exceeds an offset threshold, if yes, indicating that the metro tunnel section has obvious shape change, otherwise, indicating that the metro tunnel section does not have obvious shape change. Compared with the prior art, the method has the advantages of high measurement accuracy, comprehensive measurement, convenience in implementation and the like.

Description

technical field [0001] The invention relates to the technical field of civil engineering, in particular to a method for detecting section deformation of a subway tunnel. Background technique [0002] At present, my country's urban rail transit is developing rapidly, and more than a dozen cities have opened subways. The subway has become an important way for citizens to travel, and the responsibility for ensuring the safety of subway operation is heavy. [0003] The safety problems during shield tunnel construction and subway operation are mainly manifested in the following aspects: the soft soil layer under the tunnel softens under the long-term vibration load and causes settlement; the construction activities near the tunnel cause tunnel deformation; the underlying soil layer of the interval tunnel Water and soil erosion causes destructive longitudinal deformation; when the tunnel passes through areas with different soil conditions, the difference in soil physical propertie...

AI Technical Summary

Problems solved by technology

[0005] For the detection of the convergence deformation of the tunnel section, there are currently several methods including manual section measurement, 3D laser scanning measurement and tunnel inspection trolley measurement. Manual detection is not only low in accuracy but also takes a long time. Accuracy measurement, but the requirements for measuring instruments are high, it is not easy to implement and the cost is too high. At present, the method of measuring through the tunnel inspection trolley is mostly to detect the cracks and water seepage inside the tunnel section through image recognition. At present, there is no better method , using the detection parameters obtained by the tunnel detection car to realize the judgment of the deformation of the tunnel section

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