Device and method for integrated collection of stress and displacement of surrounding rocks

Abstract

The invention discloses a device for integrated collection of stress and displacement of surrounding rocks, which comprises a spherical body, a casing pipe, a steel wire and an optical cable, wherein a threaded hole is formed by drilling along one diameter of the spherical body; a fiber bragg grating is adhered along six different directions in the spherical body respectively; one end of the steel wire is fixed on the spherical body; and one end of the optical cable is connected with the fiber bragg gratings in the spherical body. According to the device and the method for integrated collection of stress and displacement of surrounding rocks disclosed by the invention, three-dimensional stress of a point can be calculated by measuring stresses in six directions of the point, and stress and displacement can be simultaneously measured in one drill hole, therefore, not only comparison and analysis are convenient, but also accuracy of a test result is ensured as mutual interference among a plurality of near-distance drill holes is avoided, and meanwhile, workloads of the drill holes are decreased; the fiber gratings are not influenced by electromagnetic, humid and corrosive environments, and the spherical body is sufficiently contacted with the surrounding rocks as well as with slurry poured in the holes, so that accuracy and reliability of stress measurement result are guaranteed; furthermore, the spherical body is fixed in surrounding rock holes in a way that slurry is poured into the surrounding rock holes, looseness of the spherical body is avoided, as a result, a wrong displacement test result is prevented.

Description

technical field [0001] The invention relates to a collection device and method, in particular to a surrounding rock stress and displacement integrated collection device and method suitable for underground engineering monitoring. Background technique [0002] In order to ensure the safety and stability of the underground space project and provide a reliable basis for the optimal design of the project, it is necessary to carry out on-site monitoring of the stress and displacement of the surrounding rock of the project. [0003] At present, the monitoring of surrounding rock stress and displacement on site generally adopts borehole stress gauge (vibrating wire or oil pressure type) and multi-point displacement gauge to monitor surrounding rock stress and displacement respectively, which has the following deficiencies: [0004] (1) The workload of drilling is heavy: Since stress monitoring and displacement monitoring are independent of each other, and one drilling hole can only ...

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Problems solved by technology

[0004] (1) The workload of drilling is heavy: since stress monitoring and displacement monitoring are independent of each other, and one drilling hole can only monitor the stress at one point, multiple test holes need to be drilled to monitor the stress and displacement at different depths of surrounding rock

[0005] (2) Mutual interference between boreholes: In order to compare and analyze the stress and displacement evolution law of a certain place in the surrounding rock, it is necessary to drill multiple stress measurement holes and displacement measurement holes at close range at the position to be measured, and there is mutual interference between the drill holes. Distort the test results

[0006] (3) The borehole stress gauge can only measure unidirectional stress: the existing borehole stress gauge, whether it is a vibrating wire type or an oil pressure type, can only roughly monitor the stress in one direction at a certain point, and cannot test the stress in this direction. 3D stress at point

[0007] (4) Poor reliability: the drilling stress gauge is not in sufficient contact with the surrounding rock, and the force transmission is unreliable, resulting in inaccurate test results; the base point of the multi-point displacement gauge is generally fixed mechanically, which is prone to loosening and sliding, which leads to test results False; test data are less reliable for comparison analysis since stress and displacement at the same location are not available

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