CN103604382A - Bellows-distributed optical fiber measuring sensor - Google Patents

Abstract

Translated fromChinese

本发明涉及一种波纹管分布式光纤测量传感器，它包括感测光纤，其特征在于还包括波纹管，所述的感测光纤上至少串套1个波纹管，被串套的波纹管两两之间的间距大小可调，每个波纹管的两端用高强度环氧树脂封注形成注胶固定段，所述的感测光纤的数量为1束，其中有1根为预应力感测光纤、其余的为缩折式感测光纤，受力时的缩折式感测光纤可在波纹管中的原位上作轴向滑动或伸缩。本发明能够有效解决现有光纤传感测量过程中光纤被损坏或拉断的难题，可实现对岩土体大变形或大位移的测量，以提高光纤传感测量的成功率，广泛适用于地面沉降、地裂缝、地面塌陷、滑坡、路基、矿山井巷等岩土体变形监测。

The invention relates to a bellows distributed optical fiber measurement sensor, which includes a sensing optical fiber, and is characterized in that it also includes a bellows, and at least one bellows is serially sleeved on the sensing optical fiber, and the bellows that are serially sleeved are two by two. The distance between them is adjustable, and the two ends of each corrugated pipe are sealed with high-strength epoxy resin to form a glue-injected fixed section. The number of sensing optical fibers is 1 bundle, and one of them is prestressed sensing The optical fiber and the rest are retractable sensing optical fibers, and the retractable sensing optical fibers can axially slide or expand and contract in their original positions in the bellows when stressed. The invention can effectively solve the problem that the optical fiber is damaged or broken in the existing optical fiber sensing measurement process, and can realize the measurement of large deformation or large displacement of rock and soil, so as to improve the success rate of optical fiber sensing measurement, and is widely applicable to the ground Rock and soil deformation monitoring such as settlement, ground fissures, ground subsidence, landslides, roadbeds, mine shafts, etc.

Description

A kind of corrugated tube distribution type fiber-optic survey sensor

Affiliated technical field

The invention belongs to Fibre Optical Sensor field of measuring technique, particularly relate to a kind of corrugated tube distribution type fiber-optic survey sensor.

Background technology

Optical fiber sensing technology be last century the eighties be accompanied by the development of light transmitting fiber and Fibre Optical Communication Technology and develop rapidly a kind ofly take light as carrier, optical fiber is medium, the New Sensing Technology of perception and the measured outer signals of transmission, wherein Distributed Optical Fiber Sensing Techniques is one of technology of tool future.The demodulation techniques of distributed fiberoptic sensor mainly contain: based on spontaneous Brillouin light time domain reflection technology (Brillouin Optical Time Domain Reflectormeter, abbreviation: BOTDR), based on (the Brillouin Optical Time Domain Analysis abbreviation: BOTDA) of excited Brillouin optical time domain reflection technology, based on (the Brillouin Optical Frequently Time Domain Analysis abbreviation: BOFDA) of stimulated Brillouin optical frequency domain reflection technology, based on Raman light time domain reflection technology (Raman Optical Time Domain Reflectormeter, abbreviation: (the Optical Time Domain Reflectometer abbreviation: OTDR) etc. of optical time domain reflection technology ROTDR) and based on Rayleigh scattering and Fresnel reflection.Due to the plurality of advantages of Distributed Optical Fiber Sensing Techniques, Geological Engineering and Geotechnical Engineering field have been widely used at present.Particularly in recent years, the application extremely both domestic and external common concern of Distributed Optical Fiber Sensing Techniques in land subsidence, ground fissure, surface collapse, landslide, roadbed, the monitoring of mine working isolith soil deformation.But in Rock And Soil deformation monitoring, tend to exist large deformation or large displacement measurement, exceed the range of general Fibre Optical Sensor or break damage etc. because External Force Acting causes, thereby cause monitoring interrupt or lost efficacy.

Chinese patent application 200910032861.7 has proposed a kind of " distributed optical fiber temperature sensor with high spatial resolution ", this sensor, adopt the arrangement mode of unique spiral winding, increase the sensor fibre length in unit length test section, make the temperature test spatial discrimination precision based on BOTDR technology bring up to several centimetre-sized, though having, it can improve test space resolving accuracy, improve the survival rate that sensor fibre is implanted, be applicable to the advantage of rugged surroundings and heavy construction temperature detection, but also exist following obviously not enough: the one, this sensor adopts spiral arrangement mode and makes optical fiber that strain not occur, be applicable to temperature detection, cannot be for the monitoring to Rock And Soil distortion, the 2nd, this sensor adopts single fiber pattern, once break in actual applications damage, just will cause whole monitoring to be interrupted, the 3rd, this sensor fiber, in without pre-stressed state, cannot be realized the monitoring of compression deformation state.

How to overcome the deficiencies in the prior art and become one of current stud welding field emphasis difficult problem urgently to be resolved hurrily.

 

Summary of the invention

The present invention seeks to provides a kind of corrugated tube distribution type fiber-optic survey sensor for overcoming the deficiencies in the prior art, the present invention can effectively solve the difficult problem that optical fiber in Fibre Optical Sensor measuring process is damaged or break, can realize the measurement to Rock And Soil large deformation or large displacement, the success ratio of measuring to improve Fibre Optical Sensor.

A kind of corrugated tube distribution type fiber-optic survey sensor proposing according to the present invention, it comprises sensing optical fiber, characterized by further comprising corrugated tube, on described sensing optical fiber, at least string overlaps 1 corrugated tube, adjustable by the corrugated tube of string cover spacing size between any two, the two ends of each corrugated tube are noted and are formed injecting glue canned paragraph by high strength epoxy resin envelope, the quantity of described sensing optical fiber is 1 bundle, wherein there is 1 for prestress sensing optical fiber, remaining is contractible sensing optical fiber, contractible sensing optical fiber when stressed can be in axial sliding or stretch in the original position in corrugated tube.

Principle of work of the present invention is: the present invention is in use glued to measurand surface or direct-burried is inner in measurand, the deflection of the previous stage sensing optical fiber in corrugated tube is set reaches and damages or break before the limit, the sensing optical fiber of a rear level length will be taken over job automatically in moment, and possess with 1 bundle sensing optical fiber the Fibre Optical Sensor measurement that the oil storage method that can take over job meets large deformation or large displacement, to improve the survival rate of optical fiber measurement sensor, the present invention is by outside BOTDR/A, BOFDA, the (FBG) demodulator such as ROTDR and OTDR carries out data acquisition transmission, be applicable to land subsidence completely, ground fissure, surface collapse, landslide, roadbed or the monitoring of mine working isolith soil deformation.

The present invention compared with prior art its remarkable advantage is: the one, and bellows surface of the present invention has ripple struction, can obtain more and contact area measurand, to promote coupling and the distortion transitivity in Fibre Optical Sensor measurement; The 2nd, the sensing optical fiber length arranging in corrugated tube of the present invention has contracting folding endurance, when previous stage sensing optical fiber is damaged or breaks, the sensing optical fiber that can be had contracting folding length by rear one-level is taken over, and has greatly improved the survival rate of optical fiber measurement sensor in to the monitoring of Rock And Soil large deformation or large displacement; The 3rd, in corrugated tube of the present invention, be provided with 1 bundle sensing optical fiber, applicable to different sensing patterns and different sensing accuracies, to meet different deformation monitoring requirements; The 4th, corrugated tube of the present invention two ends are provided with injecting glue canned paragraph, for the sensing optical fiber physical positioning arranging in corrugated tube, both can improve the compatibility of deformation performance of optical fiber measurement sensor, and can effectively prevent again strain diffusion, and make the work of optical fiber measurement sensor more reliable.The present invention is specially adapted to the measurement to Rock And Soil large deformation or large displacement.

 

Accompanying drawing explanation

Fig. 1 is the structural representation of a kind of corrugated tube distribution type fiber-optic survey sensor of proposing of the present invention.

Fig. 2 is the schematic diagram of single corrugated tube cellular construction of the present invention.

Fig. 3 is the schematic diagram of corrugated tube injecting glue canned paragraph cross-sectional structure of the present invention.

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Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.

In conjunction with Fig. 1 and Fig. 2, a kind of corrugated tube distribution type fiber-optic survey sensor that the present invention proposes, it comprises sensing optical fiber (2), characterized by further comprising corrugated tube (1), on described sensing optical fiber (2), at leaststring overlaps 1 corrugated tube (1), adjustable by the corrugated tube (1) of string cover spacing size between any two, the two ends of each corrugated tube (1) are noted and are formed injecting glue canned paragraph (3) by high strength epoxy resin envelope, the quantity of described sensing optical fiber (2) is 1 bundle, wherein there is 1 for prestress sensing optical fiber (2-1), remaining is contractible sensing optical fiber (2-2), contractible sensing optical fiber (2-2) when stressed can be in axial sliding or stretch in the original position in corrugated tube (1).

The further preferred version of the present invention is:

Sensing optical fiber of the present invention (2) is tight tube fiber, loose tube fiber, single-mode fiber, multimode optical fiber or optical cable; The prestress of the prestress sensing optical fiber (2-1) in sensing optical fiber (2) is 2000 microstrains; The quantity of sensing optical fiber (2) is 3～10; The sensing optical fiber (2) of similar material should be set in same optical fiber measurement sensor, but have the also capable of choosing multiple combination of specific (special) requirements.

Corrugated tube of the present invention (1) for thering is higher-strength, deformability, get well and meet easy machining and corrosion resistivity metallic bellows, be shaped as tubulose, tube wall for double-deck, three layers or sandwich construction, pipe thickness 6～15mm, internal diameter be that 14～50mm, length are at least 50 ripple numbers, length and can reach at most that hundreds of is individual, several thousand several ten thousand ripple numbers even.

In conjunction with Fig. 3, injecting glue canned paragraph (3) is the stationary installation of corrugated tube (1) and sensing optical fiber (2), it is realized by adopting high strength epoxy resin to seal notes at corrugated tube (1) two ends, the sensing optical fiber (2) that is about to lay in corrugated tube (1) and its pipe is fixed, and guarantees again that the contractible sensing optical fiber (2-2) in sensing optical fiber (2) can be in axial sliding or stretch in the original position in corrugated tube (1) simultaneously.

Specific embodiments of the invention and requirement are:

Embodiment 1, take that to make the corrugated tube distribution type fiber-optic survey sensor that length is 1000m be example.According to designing requirement of the present invention: corrugated tube (1) length is that 1.5m, internal diameter are that 50mm, pipe thickness are that 15mm, ripple number are 150, tube wall is four-layer structure, corrugated tube (1) both can directly customize by described specification, can by length, be also 1.5m segmentation intercepting by the finished product of overlength degree; The quantity of sensing optical fiber (2) is 10, the length 1000m of the 1st prestress sensing optical fiber (2-1) of take is benchmark, and the 2nd length to the 10th contractible sensing optical fiber (2-2) is followed successively by 1012m, 1024m, 1036m, 1048m, 1060m, 1072m, 1084m, 1096m, 1108 m; Adopt (1) 400 of corrugated tube, according to corrugated tube (1) between two spacing 1m go here and there successively and be enclosed within on sensing optical fiber (2); Sensing optical fiber (2) is carried out to classification by length, prestress application 2000 microstrains to the 1st grade of prestress sensing optical fiber (2-1), the length that the 2nd, 3,4,5,6,7,8,9,10 grades of contractible sensing optical fibers (2-2) are arranged in corrugated tube (1) is reserved respectively 0.03m, 0.06m, 0.09m, 0.12m, 0.15m, 0.18m, 0.21m, 0.24m, 0.27m successively; To corrugated tube (1) two ends, adopt 10 minutes quick-dry type high strength epoxy resins to carry out injecting glue, in injecting glue process, guarantee the equal in length of corrugated tube (1) sensing optical fiber (2) between any two; After injecting glue completes, after high strength epoxy resin is fixed, just form the corrugated tube distribution type fiber-optic survey sensor that a complete length is 1000m.

Embodiment 2, take that to make the corrugated tube distribution type fiber-optic survey sensor that length is 800m be example.According to designing requirement of the present invention: corrugated tube (1) length is that 1.5m, internal diameter are that 40mm, pipe thickness are that 13mm, ripple number are about 150, tube wall is four-layer structure, corrugated tube (1) both can directly customize by described specification, can by length, be also 1.5m segmentation intercepting by the finished product of overlength degree; The quantity of sensing optical fiber (2) is 8, the length 800m of the 1st prestress sensing optical fiber (2-1) of take is benchmark, and the 2nd length to the 8th contractible sensing optical fiber (2-2) is followed successively by 809.6m, 819.2m, 828.8m, 838.4m, 848m, 857.6m, 867.2m; Adopt (1) 320 of corrugated tube, according to corrugated tube (1) between two spacing 1m go here and there successively and be enclosed within on sensing optical fiber (2); Sensing optical fiber (2) is carried out to classification by length, prestress application 2000 microstrains to the 1st grade of prestress sensing optical fiber (2-1), the length that the 2nd, 3,4,5,6,7,8 grades of contractible sensing optical fibers (2-2) are arranged in corrugated tube (1) is reserved respectively 0.03m, 0.06m, 0.09m, 0.12m, 0.15m, 0.18m, 0.21m successively; To corrugated tube (1) two ends, adopt 10 minutes quick-dry type high strength epoxy resins to carry out injecting glue, in injecting glue process, guarantee the equal in length of corrugated tube (1) sensing optical fiber (2) between any two; After injecting glue completes, after high strength epoxy resin is fixed, just form the corrugated tube distribution type fiber-optic survey sensor that a complete length is 800m.

Embodiment 3, take that to make the corrugated tube distribution type fiber-optic survey sensor that length is 500m be example.According to designing requirement of the present invention: corrugated tube (1) length is that 1m, internal diameter are that 30mm, pipe thickness are that 12mm, ripple number are about 100, tube wall is four-layer structure, corrugated tube (1) both can directly customize by described specification, can by length, be also 1m segmentation intercepting by the finished product of overlength degree; The quantity of sensing optical fiber (2) is 6, and the length 500m of the 1st prestress sensing optical fiber (2-1) of take is benchmark, and the 2nd length to the 8th contractible sensing optical fiber (2-2) is followed successively by 500m, 505m, 510m, 515m, 520m, 525m; Adopt (1) 250 of corrugated tube, according to corrugated tube (1) between two spacing 1m go here and there successively and be enclosed within on sensing optical fiber (2); Sensing optical fiber (2) is carried out to classification by length, prestress application 2000 microstrains to the 1st grade of prestress sensing optical fiber (2-1), the length that the 2nd, 3,4,5,6 grades of contractible sensing optical fibers (2-2) are arranged in corrugated tube (1) is reserved respectively 0.02m, 0.04m, 0.06m, 0.08m, 0.1m successively; To corrugated tube (1) two ends, adopt 10 minutes quick-dry type high strength epoxy resins to carry out injecting glue, in injecting glue process, guarantee the equal in length of corrugated tube (1) sensing optical fiber (2) between any two; After injecting glue completes, after high strength epoxy resin is fixed, just form the corrugated tube distribution type fiber-optic survey sensor that a complete length is 500m.

Embodiment 4, take that to make the corrugated tube distribution type fiber-optic survey sensor that length is 200m be example.According to designing requirement of the present invention: corrugated tube (1) length is that 1m, internal diameter are that 25mm, pipe thickness are that 9mm, ripple number are about 100, tube wall is four-layer structure, corrugated tube (1) both can directly customize by described specification, can by length, be also 1m segmentation intercepting by the finished product of overlength degree; The quantity of sensing optical fiber (2) is 5, and the length 200m of the 1st prestress sensing optical fiber (2-1) of take is benchmark, and the 2nd length to the 5th contractible sensing optical fiber (2-2) is followed successively by 202m, 204m, 206m, 208m; Adopt (1) 100 of corrugated tube, according to corrugated tube (1) between two spacing 1m go here and there successively and be enclosed within on sensing optical fiber (2); Sensing optical fiber (2) is carried out to classification by length, prestress application 2000 microstrains to the 1st grade of prestress sensing optical fiber (2-1), the length that the 2nd, 3,4,5 grades of contractible sensing optical fibers (2-2) are arranged in corrugated tube (1) is reserved respectively 0.02m, 0.04m, 0.06m, 0.08m successively; To corrugated tube (1) two ends, adopt 10 minutes quick-dry type high strength epoxy resins to carry out injecting glue, in injecting glue process, guarantee the equal in length of corrugated tube (1) sensing optical fiber (2) between any two; After injecting glue completes, after high strength epoxy resin is fixed, just form the corrugated tube distribution type fiber-optic survey sensor that a complete length is 200m.

Embodiment 5, take that to make the corrugated tube distribution type fiber-optic survey sensor that length is 100m be example.According to designing requirement of the present invention: corrugated tube (1) length is that 1m, internal diameter are that 20mm, pipe thickness are that 8mm, ripple number are about 200, tube wall is four-layer structure, corrugated tube (1) both can directly customize by described specification, can by length, be also 1m segmentation intercepting by the finished product of overlength degree; The quantity of sensing optical fiber (2) is 4, and the length 100m of the 1st prestress sensing optical fiber (2-1) of take is benchmark, and the 2nd length to the 4th contractible sensing optical fiber (2-2) is followed successively by 101m, 102m, 103m; Adopt (1) 50 of corrugated tube, according to corrugated tube (1) between two spacing 1m go here and there successively and be enclosed within on sensing optical fiber (2); Sensing optical fiber (2) is carried out to classification by length, prestress application 2000 microstrains to the 1st grade of prestress sensing optical fiber (2-1), the length that the 2nd, 3,4 grades of contractible sensing optical fibers (2-2) are arranged in corrugated tube (1) is reserved respectively 0.02m, 0.04m, 0.06m successively; To corrugated tube (1) two ends, adopt 10 minutes quick-dry type high strength epoxy resins to carry out injecting glue, in injecting glue process, guarantee the equal in length of corrugated tube (1) sensing optical fiber (2) between any two; After injecting glue completes, after high strength epoxy resin is fixed, just form the corrugated tube distribution type fiber-optic survey sensor that a complete length is 100m.

Embodiment 6, take that to make the corrugated tube distribution type fiber-optic survey sensor that length is 10m be example.According to designing requirement of the present invention: corrugated tube (1) length is that 1m, internal diameter are that 14mm, pipe thickness are that 6mm, ripple number are about 250, tube wall is four-layer structure, corrugated tube (1) both can directly customize by described specification, can by length, be also 1m segmentation intercepting by the finished product of overlength degree; The quantity of sensing optical fiber (2) is 3, and the length 10m of the 1st prestress sensing optical fiber (2-1) of take is benchmark, and the 2nd length to the 4th contractible sensing optical fiber (2-2) is followed successively by 10.1m, 10.2m; Adopt (1) 5 of corrugated tube, according to corrugated tube (1) between two spacing 1m go here and there successively and be enclosed within on sensing optical fiber (2); Sensing optical fiber (2) is carried out to classification by length, prestress application 2000 microstrains to the 1st grade of prestress sensing optical fiber (2-1), the length that the 2nd, 3 grades of contractible sensing optical fibers (2-2) are arranged in corrugated tube (1) is reserved respectively 0.02m, 0.04m successively; To corrugated tube (1) two ends, adopt 10 minutes quick-dry type high strength epoxy resins to carry out injecting glue, in injecting glue process, guarantee the equal in length of corrugated tube (1) sensing optical fiber (2) between any two; After injecting glue completes, after high strength epoxy resin is fixed, just form the corrugated tube distribution type fiber-optic survey sensor that a complete length is 10m.

In above-described embodiment, the length in reserve of contractible sensing optical fibers at different levels (2-2) is that the length of breaking Shi Suoying and increasing by the 1st grade of prestress sensing optical fiber (2-1) increases progressively successively in each corrugated tube (1), prestress sensing optical fiber (2-1) pull-off force calculates by 2000 microstrains, if corrugated tube (1) length is 1m, length in reserve since the contractible sensing optical fiber (2-2) of the 2nd grade in this corrugated tube (1) is followed successively by 0.02m, 0.04m ..., by that analogy; The number of corrugated tube (1)=total length of the present invention/[corrugated tube (1) length+corrugated tube (1) is spacing between two]; The length in reserve of the total length of sensing optical fibers at different levels (2)=total length+corrugated tube of the present invention (1) number * contractible sensing optical fibers at different levels (2-2).

The present invention, through validation trial, has obtained satisfied effect.

Claims (6)

1. a corrugated tube distribution type fiber-optic survey sensor, it comprises sensing optical fiber (2), characterized by further comprising corrugated tube (1), on described sensing optical fiber (2), at least string overlaps 1 corrugated tube (1), adjustable by the corrugated tube (1) of string cover spacing size between any two, the two ends of each corrugated tube (1) are noted and are formed injecting glue canned paragraph (3) by high strength epoxy resin envelope, the quantity of described sensing optical fiber (2) is 1 bundle, wherein there is 1 for prestress sensing optical fiber (2-1), remaining is contractible sensing optical fiber (2-2), contractible sensing optical fiber (2-2) when stressed can be in axial sliding or stretch in the original position in corrugated tube (1).

2. a kind of corrugated tube distribution type fiber-optic survey sensor according to claim 1, is characterized in that sensing optical fiber (2) is for tight tube fiber, loose tube fiber, single-mode fiber, multimode optical fiber or optical cable.

3. a kind of corrugated tube distribution type fiber-optic survey sensor according to claim 1, the prestress that it is characterized in that the prestress sensing optical fiber (2-1) in sensing optical fiber (2) is 2000 microstrains.

4. according to a kind of corrugated tube distribution type fiber-optic survey sensor described in claim 1,2 or 3, the quantity that it is characterized in that sensing optical fiber (2) is 3～10.

5. according to a kind of corrugated tube distribution type fiber-optic survey sensor described in claim 1,2 or 3, it is characterized in that corrugated tube (1) for metallic bellows, be shaped as tubulose, tube wall for double-deck, three layers or sandwich construction, pipe thickness 6～15mm, internal diameter be that 14～50mm, length are at least 50 ripple numbers.

6. a kind of corrugated tube distribution type fiber-optic survey sensor according to claim 4, it is characterized in that corrugated tube (1) material be metallic bellows, be shaped as tubulose, tube wall for double-deck, three layers or sandwich construction, pipe thickness 6～15mm, internal diameter be that 14～50mm, length are at least 50 ripple numbers.

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