A Method of Measuring the Lateral Force of Anchor Rod Using Fiber Bragg Grating

Abstract

A method of using a fiber bragg grating to measure an anchor-rod lateral force is disclosed. In the invention, a measurement anchor rod formed by an anchor rod, an anchor rod anchoring agent, the fiber bragg grating, a base plate, an optical cable, an anchor rod locking device, an optical cable and a demodulation instrument is used and the fiber bragg grating is used to measure the lateral force of the measurement anchor rod. In the invention, the fiber bragg grating is adopted and a size, a direction and a position of a tangential force on the anchor rod are accurately measured; a problem that an existing force measurement anchor rod only can measure an axial force on the anchor rod is solved; reliability of force-bearing anchor rod measurement precision is increased; a force bearing condition of the anchor rod in a drill hole is known; and a basic data is provided for researching the force bearing condition of the anchor rod in a rock stratum.

Description

technical field [0001] The invention relates to a method for detecting the lateral force of an anchor rod, in particular to a method for measuring the lateral force of an anchor rod by using an optical fiber grating sensor. Background technique [0002] Fiber Bragg Grating is referred to as FBG. FBG sensor is a good invention in the field of sensing in the 1990s. It is a sensor product based on FBG as the core device. It has the characteristics of high measurement accuracy, real-time monitoring, anti-electromagnetic interference and anti-lightning strike. Therefore, in the fields of oil industry, mining and building structure safety monitoring, fiber grating sensors are mainly used to replace old-fashioned electrical signal sensors. In the field of force-measuring bolts, fiber grating sensors have been widely used. [0003] The publication number is CN 203097917 U, and the disclosed name is "a force-measuring anchor rod". The invention adopts two symmetrical grooves along t...

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Problems solved by technology

[0003] The publication number is CN 203097917 U, and the disclosed name is "a force-measuring anchor rod". The invention adopts two symmetrical grooves along the anchor rod and six strain gauges are equidistantly arranged in each groove, and uses the shell to measure the strain gauge. The sheet is protected and used to measure the force of the stressed anchor rod, but this kind of resistance strain gauge is not stable enough and is easily deformed by the external environment. Especially in the case of harsh mine environment, the measurement is not accurate and the reliability is low. not tall

[0004] The publication number is CN 106677812 [1] A, the name is disclosed as "a fiber grating force-measuring anchor rod". This invention uses a fiber grating sensor to measure the force condition of the anchor rod. According to the extrusion force on the backing plate to measure the pull-out force on the anchor rod, the force-measuring anchor rod uses a fiber grating sensor to measure the force of the stressed anchor rod, which improves the stability of the sensor, but the number of sensors is small and the setting On the backing plate, it is impossible to accurately measure the force on the anchor rod

[0005] The publication number is CN 202690096 U, which discloses a kind of "Fiber Bragg Grating Force Measuring Anchor". In this invention, a pair of fiber grating sensors are arranged on both sides of the anchor, but the number of installations is small and the structure is simple. The force condition of the anchor rod bending cannot be obtained except for the strain condition

[0006] The above-mentioned existing monitoring bolt structure has certain deficiencies in realizing the force detection of the bolt, so it is of great practical value to seek a more perfect detection bolt structure

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