Deep foundation pit detection method based on white-light digital image frequency domain analysis method

Abstract

The invention provides a deep foundation pit detection method based on a white-light digital image frequency domain analysis method. The deep foundation pit detection method includes the following steps: step 1, utilizing digital image input equipment to respectively record deformation of a test piece or gray level comparison images before and after moving; step 2, uploading the gray level comparison images to an image processing system; step 3, digitalizing the uploaded gray level comparison images by the image processing system; step 4, taking random gray level distribution or feature stripe on the surface of the test piece as a carrier to extract displacement information from the digitalized gray level comparison images through the white-light digital image frequency domain analysis method. A testing system in the white-light digital image frequency domain analysis method is simple, no special treatment is needed for the testing surface generally, testing conditions are simple, a vibration isolating platform is not needed, and the deep foundation pit detection method can be used in any place, thereby being wide in application range.

Description

technical field [0001] The invention belongs to the field of displacement and deformation measurement, and in particular relates to a deep foundation pit detection method based on a white light digital image frequency domain analysis method. Background technique [0002] A deep foundation pit is a temporary pit excavated for the foundation of a building structure. Its function is to provide space for the smooth development of the foundation construction, so that the masonry work of the structure can be carried out according to the position specified by the design. The foundation pit support system is a temporary structure with a small safety reserve and high risk. Monitoring should be carried out during the construction of foundation pit engineering, and emergency measures should be taken. Foundation pit engineering monitoring refers to the use of precision instruments and equipment to monitor the displacement, inclination, settlement, stress, cracking, Comprehensive monit...

AI Technical Summary

Problems solved by technology

For example, laser interferometry has high sensitivity and precision, but this method has complex optical paths, difficult operation, expensive hardware facilities, and high requirements on environmental and vibration conditions, so it is difficult to achieve engineering field testing

Although the optical triangulation method has low requirements on hardware equipment, environment and vibration, the method is limited by the conditions of the measured rigid body.

The grid method has simple requirements on the optical path and low cost of hardware facilities, but it has relatively high requirements on the grid production on the surface of the test piece, and it is difficult to achieve microscopic testing

The optical path of moiré interferometry is complex, the cost of hardware facilities is high, the requirements for the test environment are high, and debugging is difficult

The three-dimensional digital image correlation method has the advantages of simple optical path, convenient operation, and can realize the digitization of experimental results. However, the method itself also has shortcomings. There are still certain requirements for lighting; the correlation operation is realized through the translation of the window, so it is affected by the rotation of the rigid body; the matching of test points before and after deformation is also prone to mismatching problems

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