Distributed optical fiber monitoring calibration and test method and device for soil deformation

Abstract

The invention relates to a distributed optical fiber monitoring calibration and test device for soil deformation. The device comprises a calibration and test main box, stress sensing optical fibers, an optical fiber demodulation instrument and a digital image acquisition and analysis device; the front face and rear face of the test main box are transparent rigid plates, and the test main box is filled with soil which is compacted in a layered mode; the stress sensing optical fibers are laid in soil in the horizontal direction and/or vertical direction segment by segment; the optical fiber demodulation instrument is connected with the stress sensing optical fibers and acquires stress data in the soil; the digital image acquisition and analysis device is used for measuring displacement and stress of soil in contact with the front transparent rigid plate and the rear transparent rigid plate. By means of the distributed optical fiber monitoring calibration and test method and device, distributed optical fiber monitoring readings for soil deformation can be calibrated, the interaction and deformation coupling between the soil and the optical fibers are researched, and the spatial-temporal evolutional law of stress in the soil under different working conditions such as loading, unloading, digging and seepage is obtained.

Description

technical field [0001] The invention relates to the technical field of soil deformation and distributed optical fiber monitoring engineering, in particular to a soil deformation distributed optical fiber monitoring calibration and test device. Background technique [0002] The deformation of soil is an important index to evaluate the stable state of soil. For some large-scale projects such as slope filling, dam construction and tunnel excavation, the implementation of distributed deformation monitoring will help to obtain the abnormal parts of soil stress and deformation in time, and take corresponding engineering countermeasures to ensure the normal construction and operation of the project . Existing non-contact soil deformation measurement technologies, such as global positioning system, remote sensing, laser scanning, and photogrammetry, can only obtain deformation information on the soil surface, and their measurement accuracy is usually not high. Although rock and so...

AI Technical Summary

Problems solved by technology

This method is relatively convenient for construction, but the interaction mechanism and coordinated deformation between the soil and the strain sensing optical fiber have not been fully understood, and there is no scientific basis for the selection of the strain sensing optical fiber and the setting of the anchor point. The reliability of optical fiber monitoring results has great uncertainty, which greatly restricts the popularization and application of this technology in engineering

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