Three-dimensional borehole stress fiber grating sensor and monitoring method thereof

Abstract

The invention discloses a three-dimensional borehole stress fiber bragg grating sensor and a monitoring method thereof. The three-dimensional borehole stress fiber bragg grating sensor comprises a corrugated pipe mounting seat, a pressed corrugated pipe and a tensile corrugated pipe, the corrugated pipe mounting seat is provided with a pressed corrugated pipe and a stretching corrugated pipe which are different in diameter, the top end of the pressed corrugated pipe is provided with a pressed block, the top end of the stretching corrugated pipe is provided with a cantilever beam, and the cantilever beam is provided with a fiber grating; the pressed corrugated pipe receives drilling stress applied by the pressed block in different directions and transmits the drilling stress to the stretching corrugated pipe, and the stretching corrugated pipe drives the cantilever beam to generate vertical displacement through the pressure difference caused by the diameter. A double-corrugated-pipe form of a pressed corrugated pipe and a stretching corrugated pipe with different diameters is adopted, and a pressure difference is formed by utilizing the difference of the diameters of the two corrugated pipes, so that the stretching corrugated pipe generates upward displacement, and a monitoring effect is achieved.

Description

technical field [0001] The invention relates to the technical field of measurement, in particular to a three-dimensional borehole stress fiber grating sensor and a monitoring method thereof. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Electronic stress sensors used in traditional coal mines generally use highly integrated pressure-sensitive chips to output electrical signals. The overall structure of this method is relatively simple, but there are disadvantages such as single range, non-intrinsic safety, limited transmission distance, and insufficient resistance to electrical interference. [0004] Fiber grating sensors generally only use bellows and strain beam structures. The structure of the sensor is simple, but the practical application of this structure is not easy to realize multi-directional monitoring; because the strain rang...

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Problems solved by technology

The overall structure of this method is relatively simple, but there are disadvantages such as single range, non-intrinsically safe, limited transmission distance, and insufficient ability to resist electrical interference.

[0004] Fiber Bragg grating sensors generally only use bellows and strain beam structures. The structure of the sensor is simple, but it is difficult to realize multi-directional monitoring in practical applications of this structure; since the strain range of the fiber grating is different from that of the bellows, the fiber grating can be directly The strain of the bellows matches the strain of the bellows, which not only limits the use range of the two strain elements, but also makes it difficult to adjust the measurement accuracy or measurement range of the sensor according to the application requirements. Therefore, for high-sensitivity monitoring scenarios, or large-range monitoring Apps are restricted

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