CN113639646A - Full-time global online monitoring device and method for deformation of large engineering structure - Google Patents
Full-time global online monitoring device and method for deformation of large engineering structure Download PDFInfo
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Abstract
The invention discloses a full-time global online monitoring device and method for large engineering structure deformation, belongs to the technical field of large safety monitoring, and can solve the technical problems of wide coverage range and high precision required by large engineering structure deformation monitoring. Because the sensing optical cables among the nodes are arranged in a crossed manner, differential detection is realized, the influence of common mode factors is eliminated, the sensing optical cables are insensitive to temperature and displacement in other directions, and the stability and reliability of the system are effectively improved. The system has simple structure and convenient installation, thereby having large-scale engineering conditions.
Description
Technical Field
The invention belongs to the technical field of structural safety monitoring, and particularly relates to a full-time global online monitoring device and method for engineering structure deformation.
Background
In recent years, the capital construction project of our country develops rapidly, and a good foundation is laid for the economic development of our country. However, most of the infrastructure projects use reinforced concrete as a main structure, and deformation diseases such as settlement, arch collapse, slab staggering, slippage and the like easily occur under the action of complex external loads, so that the service life and the service safety of the project structure are directly influenced. Therefore, an effective detection method is urgently needed to be found to grasp the health state of the engineering structure in time. However, the detection and maintenance of the structural state of the large-scale project in China are mostly in a mode of regular maintenance or after repair, the operation, maintenance and maintenance cost is high, the efficiency is low, and the real-time performance of monitoring cannot be guaranteed. For maintenance management departments, increasingly burdensome and complex tasks are faced, and the requirement of rapid development of intelligent construction cannot be met. Therefore, new technology and new method are urgently needed to be utilized, the safety monitoring level of the large-scale engineering structure of the infrastructure is improved, and scientific data are provided for realizing intelligent operation and maintenance management of the engineering structure.
With the gradual improvement of computer performance and the gradual improvement of intelligent analysis algorithm research, a good technical reserve is provided for information analysis and processing in a safety monitoring system, so that the key for constructing the safety monitoring system lies in how to acquire real-time, comprehensive and accurate information. The technical problems of wide coverage range of monitoring requirements, large sensing monitoring scale, long transmission distance and the like of the large engineering structure are main bottlenecks which cause that the state information of the large engineering structure is difficult to comprehensively detect and acquire. In addition, the requirement on the precision of the deformation detection of the large engineering structure is high, for example, when the buckling deformation of the high-speed railway track slab exceeds 1mm, early warning is required, and when the buckling deformation of the high-speed railway track slab exceeds 3mm, the high-speed railway track slab needs to be maintained, so that a greater challenge is provided for a monitoring system.
The optical fiber sensor has the advantages of good long-term stability, remote signal transmission, easy networking, electromagnetic interference resistance and the like, gradually replaces an electric sensor with long-term stability which is difficult to ensure, and is widely applied to long-term health monitoring in the fields of bridges, tunnels, airports, railways and the like. Currently, two types are typical in the optical fiber sensing technology: the optical fiber grating sensing technology based on wavelength division multiplexing and the distributed optical fiber sensing technology based on time division multiplexing. However, when the application needs to be changed and put into practical use for large-scale engineering structures, the following problems still exist:
(1) the fiber grating sensing technology based on wavelength division multiplexing can realize high-precision measurement, but due to the limitation of the bandwidth of a light source, a sensing device needs to be independently designed and manufactured for each sensing point, and the sensing devices are constructed and installed one by one, so that the engineering operation task load is large, and the construction of a large-scale sensing network is difficult.
(2) Based on the time division multiplexing distributed optical fiber technology, the limitation of the bandwidth of a light source is broken through, and the multiplexing capacity of the sensing points on a single optical fiber is greatly improved.
The latest research hotspots of optical fiber sensing technology: the large-capacity fiber grating array sensor adopts the wavelength division and time division hybrid multiplexing principle, has the advantages of high measurement precision and large multiplexing capacity, and provides a potential solution for realizing high-precision, long-distance and large-capacity sensing detection. However, in the aspect of temperature and vibration detection, the conventional fiber grating array sensor engineering application mainly solves the problem of how to realize large-range and high-precision deformation displacement detection.
Disclosure of Invention
The invention provides a full-time global monitoring method and system for large engineering structure deformation based on fiber grating array sensing, aiming at the technical problems of wide covering range, large sensing scale and high precision requirement of large engineering structure deformation monitoring.
The invention adopts the following technical scheme:
a full-time global online monitoring system for large engineering structure deformation comprises a fiber grating array strain sensing optical cable, a fiber grating array demodulation instrument and a computer which are distributed in a crossed mode. The fiber bragg grating array strain sensing optical cable is continuously and crossly arranged to form N deformation detection units, and large-scale and high-precision deformation monitoring of a large-scale engineering structure is achieved. Different installation processes and methods are adopted for different application scenes:
(1) aiming at newly repaired large-scale engineering, the method for fixing the fiber grating array optical cable on the tested structure comprises the following steps: before the concrete is poured into the structure, the array grating strain sensing optical cable is continuously cross-tied on the steel bars and then is poured into a whole with the concrete structure.
(2) Aiming at the existing large-scale project to be monitored, 2 methods for fixing the fiber grating array optical cable on the structure to be monitored are provided:
a) and the surface of the structure to be detected is stuck and fixed. Firstly, the array grating strain sensing optical cable is continuously and crossly arranged and positioned on the surface of a structure to be measured by utilizing a line card, structural glue is coated on the positioned array grating strain sensing optical cable, and a cover plate is additionally arranged for protection.
b) And a tensioning device is additionally arranged on the surface of the structure to be measured. The fiber bragg grating strain sensing optical cable is fixed on a measured engineering structure by using N +1 tensioning devices, and is in a tensioning state and used for sensing strain generated by large-range and long-distance structural deformation.
The tensioning device comprises a bottom plate, an optical cable clamping block, a tensioning bolt and an opening metal pipe. The bottom plate is directly connected and fixed with the measured engineering structure, the optical cable clamping block is installed on the bottom plate through bolts, and the tension degree of the fiber bragg grating strain sensing optical cable is adjusted through the tensioning bolts.
The bottom plate is provided with 2 slotted holes and 2 boss structures. 2 slotted holes are used for fixing the optical cable clamping block on a tested engineering structure, and 2 bosses are respectively connected with 2 optical cable clamping blocks.
And the two ends of the optical cable clamping block are respectively provided with an optical cable clamping structure, and the optical cable is sleeved on the open metal tube and then is put into the clamping structure and is compressed.
Through holes are formed in the middle of the optical cable clamping block and the boss, so that the through holes are coaxial and are connected through a tensioning bolt.
The tensioning bolt is used for pulling the optical cable clamp splice, realizes the adjustment of optical cable rate of tension, boss both sides all have 2 screw holes on the bottom plate, the both sides of optical cable clamp splice through-hole respectively have 2 direction slotted holes. And when the optical cable clamping block is pulled to a desired position, the optical cable clamping block is positioned and locked by utilizing the threaded hole and the guide slotted hole.
The invention also provides a full-time global online monitoring method for large engineering structure deformation, and the scheme is as follows:
the method comprises the steps that N tensioning devices are arranged on a measured engineering structure to serve as fixed nodes, a long-distance fiber grating array strain sensing optical cable is fixed on the measured engineering structure, optical cables among the fixed nodes are distributed in a crossed mode, the optical cable is connected into a fiber grating array sensing demodulation instrument through the sensing optical cable, and wavelength change of each grating in a fiber grating array is detected. And analyzing the wavelength data of the instrument in real time by utilizing upper computer software, and obtaining the structural deformation according to the mapping relation between the wavelength change of the array grating and the relative displacement between the structures, thereby realizing the full-time and global monitoring of the long-distance and large-range deformation of the large engineering structure.
In the above scheme, the full-time and full-domain monitoring of the large engineering structure deformation includes the following steps:
the first step is as follows: aiming at different application scenes, the N fiber bragg grating array continuous deformation detection units are arranged on the structure to be detected according to the method and the process.
The second step is that: regarding the fixed nodes as monitoring nodes, forming a deformation sensing detection unit by the cross sensing optical cables between the two monitoring nodes, taking the optical cables between the ith and (i + 1) th nodes as an analysis object, and enabling the distance between the ith and (i + 1) th nodes to be liAnd the crossed height is h, the length of the crossed 2 sections of optical cables is as follows:
when the displacement of the (i + 1) th node relative to the ith node is Δ x, the length of the 2 segments of optical cables is changed as follows:
the corresponding dependent variables are:
2-section optical cable1iAnd l2iHas a differential strain of
The above formula is transformed into
Considering the actual situation of optical cable layout, the deformation amount Δ x of the node i +1 is extremely small, so it can be assumed that the node deformation amount Δ x is far smaller than the layout height h of the fiber grating, that is, the node deformation amount Δ x is far smaller than the layout height h of the fiber grating
Δx＜＜h
Is simple and easy to obtain
According to the relation formula of the fiber grating strain and the wavelength, the above formula becomes:
in the above formula, k is the optical fiber gratingThe sensitivity coefficient of variation can be detected by detecting the change of the grating wavelength in the fiber grating array strain sensing optical cable, the strain detection precision of the fiber grating can reach pm level, and h and l are adjustediHigh-precision deformation amount detection is realized.
According to the above result, the position of the ith node is:
the absolute deformation of the ith node is as follows:
in the monitoring range of the fiber bragg grating array, nodes are selected at intervals to fix the absolute deformation of the nodes, the nodes are used as reference nodes, and the absolute deformation of each node in the monitoring universe range of the array fiber bragg grating can be realized through the above formula;
the fiber grating demodulation instrument scans the central wavelength of each fiber grating of the fiber grating array sensor in real time, transmits the wavelength data to the data processing unit through the communication interface, and realizes the real-time monitoring of the deformation of the array fiber grating monitoring universe range by utilizing the mapping relation of the wavelength and the deformation.
The invention has the following beneficial effects:
the invention can form a full-time global online monitoring system for large engineering structure deformation by using the fiber grating array sensing optical cable, the fiber grating array signal demodulation instrument and the data processing unit. Because the sensing optical cables among the nodes are arranged in a crossed manner, differential detection is realized, the influence of common mode factors is eliminated, the sensing optical cables are insensitive to temperature and displacement in other directions, and the stability and reliability of the system are effectively improved. The system respectively adopts different installation processes and methods aiming at different application scenes, is simple to construct and convenient to install, and therefore has large-scale engineering conditions.
Drawings
FIG. 1 is a schematic view of a monitoring system of the present invention;
FIG. 2 is a schematic diagram of a method for laying a continuous deformation detection unit for a new repair project according to the present invention;
FIG. 3 is a schematic view of the surface pasting process of the continuous deformation detection unit for the existing engineering according to the present invention;
FIG. 4 is a schematic layout view of a tensioning device of a continuous deformation detection unit for the existing engineering according to the present invention;
FIG. 5-1 is a schematic view of a tensioner of the present invention;
FIG. 5-2 is a schematic view of another tensioner of the present invention;
FIG. 6 is a schematic view of the bottom plate structure of the present invention;
FIG. 7-1 is a schematic view of a cable clamp block structure according to the present invention;
FIG. 7-2 is a schematic view of another cable clamp block configuration of the present invention;
FIG. 8 is a schematic view of the structure of the steel pipe of the present invention;
FIG. 9 is a schematic view of the platen structure of the present invention;
wherein: 1-a fiber grating array strain sensing optical cable; 2-fiber grating array demodulation instrument; 3-a computer; 4-reinforcing steel bars; 5-structural adhesive; 6-cover plate; 7-a tensioning device; 7-1-a bottom plate; 7-2-an optical cable clamp block; 7-3-steel pipe; 8-slotted holes; 9-boss; 10-a through hole; 11-a platen; 12-guide slot hole.
Detailed Description
The invention is further explained with reference to the accompanying drawings.
FIG. 1 shows a full-time global online monitoring device and method for large engineering structure deformation, which includes: the fiber grating array strain sensing optical cable comprises a fiber grating array strain sensing optical cable 1, a fiber grating array demodulation instrument 2 and a computer 3. The fiber bragg grating array strain sensing optical cable 1 is continuously crossed to form N continuous deformation detection units 1-1, 1-2, 1-3, … and 1-N.
In fig. 2, for a newly repaired reinforced concrete structure, the fiber grating array strain sensing optical cable 1 which is arranged in a crossed manner is firstly fixed on the steel bar 4, and then concrete is poured to integrate the fiber grating array strain sensing optical cable 1 with the engineering structure, so that the embedded laying of the deformation sensing unit is realized, and the deformation state of the engineering structure is detected in real time.
In fig. 3, for the existing engineering structure, the fiber bragg grating array strain sensing optical cable is fixed on the surface of the engineering structure by using the line card, then the fiber bragg grating array strain sensing optical cable is cured on the surface of the engineering structure by using the structural adhesive 5, and finally the fiber bragg grating array strain sensing optical cable is protected by using the cover plate 6. The structural adhesive 5 enables the fiber bragg grating array strain sensing optical cable to be closely attached to the surface of the measured engineering structure, and senses the deformation of the measured engineering structure in real time.
In fig. 4, the fiber bragg grating array strain sensing optical cable is crossly arranged on the surface of the existing engineering structure by using the tensioning device 7, so that the deformation of the engineering structure is sensed.
The tensioning device 7 comprises a bottom plate 7-1, an optical cable clamping block 7-2 and a steel pipe 7-3. The bottom plate 7-1 is a rectangular stainless steel bottom plate. Two slotted holes 8 are arranged on two sides of the middle of the bottom plate 7-1, and the whole tensioning device can be connected with a tested engineering structure. Two bosses 9 are arranged on two sides of the bottom plate 7-1 and are fixing points of the tensioning device, a through hole is formed in the middle of each boss 9 and is connected with the optical cable clamping block 7-2, and the optical cable clamping block 7-2 can be pulled through bolt connection. Two threaded holes are respectively arranged on two sides of the two bosses 9 and used for fixing and locking the tensioned optical cable clamping block 7-2.
The optical cable clamping block 7-2 has a good clamping effect and is made of aluminum alloy. The middle of the optical cable clamping block 7-2 is provided with a through hole 10 which is connected with the through hole of the boss 9 on the bottom plate 7-1 through a bolt. The two ends of the optical cable clamping block 7-2 are of optical cable clamping structures, the two ends are respectively provided with a through hole for clamping the steel pipe 7-3 so as to clamp the optical cable, a certain compression allowance is reserved between the two through holes and the outside of the two ends in a penetrating mode, threaded holes are formed in the surfaces of the two ends, and compression clamping is conducted through bolt connection. The two ends of the optical cable clamping block 7-2 can also be matched with the pressing plate 11 to clamp the steel tube 3 so as to clamp the optical cable. Two guide slot holes 12 are respectively arranged on two sides of the through hole 10 of the optical cable clamping block 7-2, and the structure has the functions of moving, guiding and fixing with the bottom plate.
The steel pipe 7-3 is made of stainless steel. An opening at one side of the steel tube 7-3 is compression deformation, and the part can play a role in protection and prevent the optical cable from being damaged in the clamping process.
Each set of tensioning device needs a bottom plate 7-1, 2 optical cable clamping blocks 7-2, 4 steel pipes 7-3 and a plurality of bolts with different specifications.
The embodiment also provides a full-time global online monitoring method for large engineering structure deformation, which comprises the following steps:
step one, installing a tensioning device:
1) and penetrating a certain number of steel pipes onto the optical cable for standby.
2) The slotted hole on the bottom plate is connected with the tested engineering structure.
3) The guide slot hole of the optical cable clamping block is connected with the threaded hole of the bottom plate through the bolt, at the moment, the bolt does not need to be screwed, the connecting position is the farthest end of the slot hole, the maximum tensioning range is reserved, and the moving resistance of the optical cable clamping block on the bottom plate is also reduced.
4) When clamping, move the opening steel pipe on the optical cable to the corresponding position at optical cable clamp splice both ends, through bolted connection clamp sleeve steel pipe on the optical cable, and then make the steel pipe compression deformation, play the effect of pressing from both sides tight optical cable.
5) And screwing the bolt between the fixing point of the bottom plate and the optical cable clamping block, namely pulling the optical cable clamping block to tension the optical cable.
6) When the optical cable reaches the pre-tensioning index, the bolt between the bottom plate and the optical cable clamping block guide structure is screwed down, and the optical cable clamping block is locked.
And secondly, arranging fixed points on the structure to be detected at certain intervals, fixing the fiber grating array optical cable on the structure to be detected, distributing the optical cables among the fixed points in a crossed manner, accessing the optical cables into the fiber grating array sensing demodulation instrument through the sensing optical cable, and detecting the wavelength change of each grating in the fiber grating array. And analyzing the wavelength data of the instrument in real time by utilizing upper computer software, and obtaining the structural deformation according to the mapping relation between the wavelength change of the array grating and the relative displacement between the structures, thereby realizing the full-time and global monitoring of the structural deformation of the large engineering.
The full-time and full-domain monitoring of the deformation of the large engineering structure comprises the following steps:
regarding the fixed point as a monitoring node, taking the optical cable between the ith and (i + 1) th nodes as an analysis object, setting the distance between the ith and (i + 1) th nodes as li, setting the crossing height as h, and setting the length of the crossed 2 segments of optical cables as:
when the displacement of the (i + 1) th node relative to the ith node is Δ x, the length of the 2 segments of optical cables is changed as follows:
the corresponding dependent variables are:
two fiber gratings1iAnd l2iHas a differential strain of
The above formula is transformed into
Considering the actual situation of the fiber grating layout, the deformation Δ x of the node i +1 is extremely small, so it can be assumed that the node deformation Δ x is much smaller than the layout height h of the fiber grating, i.e. the node deformation Δ x is much smaller than the layout height h of the fiber grating
Δx＜＜h
Is simple and easy to obtain
According to the relation formula of the fiber grating strain and the wavelength, the above formula becomes:
in the formula, k is a fiber bragg grating strain sensitivity coefficient, the detection of the relative deformation between nodes can be realized by detecting the change of the wavelength of the fiber bragg grating array, the strain detection precision of the fiber bragg grating can reach the pm level, and the high-precision deformation detection is realized by adjusting the sizes of h and li. When h is 200mm and li is 2000mm, the theoretical precision can reach 0.01 mm.
According to the above result, the position of the ith node is:
the absolute deformation of the ith node is as follows:
in the monitoring range of the fiber bragg grating array, nodes are selected at intervals to fix the absolute deformation of the nodes, the nodes are used as reference nodes, and the absolute deformation of each node in the monitoring universe range of the array fiber bragg grating can be realized through the above formula;
the fiber grating demodulation instrument scans the central wavelength of each fiber grating of the fiber grating array sensor in real time, transmits the wavelength data to the data processing unit through the communication interface, and realizes the real-time monitoring of the deformation of the array fiber grating monitoring universe range by utilizing the mapping relation of the wavelength and the deformation.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (7)
1. The utility model provides a full time universe on-line monitoring device of large-scale engineering structure deformation which characterized in that: the optical cable connector comprises a bottom plate, an optical cable clamping block and an opening metal tube, wherein two symmetrical slotted holes and two symmetrical bosses are respectively arranged on the bottom plate, the slotted holes and the bosses are arranged in a cross manner, threaded holes are respectively arranged on two sides of each boss, and a through hole is formed in the middle of each boss; the middle of the optical cable clamping block is provided with a through hole matched with the through hole of the boss, two sides of the through hole of the optical cable clamping block are respectively provided with a guide slot hole, and two ends of the optical cable clamping block are respectively provided with a through hole for clamping an optical cable.
The guide slot hole of the optical cable clamping block is connected with the threaded hole of the bottom plate through a bolt, the through hole of the optical cable clamping block is connected with the through hole on the boss of the bottom plate through a bolt, and the steel pipe is positioned in the through holes at the two ends of the optical cable clamping block.
2. The full-time global online monitoring device for large engineering structure deformation according to claim 1, characterized in that: the slotted holes are positioned on two sides of the middle of the bottom plate, the bosses are positioned on two sides of the middle of the bottom plate, and the slotted holes and the bosses are arranged in a cross shape.
3. The full-time global online monitoring device for large engineering structure deformation according to claim 1, characterized in that: the guide slot holes are symmetrically arranged relative to the axis of the through hole in the middle of the optical cable clamping block.
4. A full-time global online monitoring method for large engineering structure deformation is characterized by comprising the following steps: the method comprises the following steps:
step one, installing a tensioning device:
(1) penetrating the open metal tube onto the optical cable for standby;
(2) connecting the slotted hole of the bottom plate with the tested engineering structure;
(3) connecting the guide slot hole of the optical cable clamping block with the threaded hole of the bottom plate through a bolt, wherein the bolt is not screwed tightly;
(4) moving the open metal tube on the optical cable to the corresponding position of the two ends of the optical cable clamping block, and connecting and clamping the open metal tube sleeved on the optical cable through a bolt, so that the open metal tube is compressed and deformed to play a role in clamping the optical cable;
(5) screwing the bolt between the boss on the bottom plate and the optical cable clamping block, namely pulling the optical cable clamping block to tension the optical cable;
(6) when the optical cable reaches the pre-tensioning index, the bolt between the bottom plate and the slotted hole of the optical cable clamping block is screwed down, and the optical cable clamping block is locked;
and secondly, arranging a plurality of fixed points on the measured structure, fixing the fiber grating array optical cable on the measured engineering structure, distributing the optical cables among the fixed points in a crossed manner, accessing the optical cables into the fiber grating array sensing demodulation instrument through the sensing optical cable, and detecting the wavelength change of each grating in the fiber grating array. And analyzing the wavelength data of the instrument in real time by utilizing upper computer software, and obtaining the structural deformation according to the mapping relation between the wavelength change of the array grating and the relative displacement between the structures, thereby realizing the full-time and global monitoring of the structural deformation of the large engineering.
5. The full-time global online monitoring method for large engineering structure deformation according to claim 4, characterized in that: in the second step, the full-time and full-domain monitoring of the deformation of the long-distance engineering structure comprises the following steps:
regarding the fixed point as a monitoring node, taking the optical cable between the ith and (i + 1) th nodes as an analysis object, setting the distance between the ith and (i + 1) th nodes as li, setting the crossing height as h, and setting the length of the crossed 2 segments of optical cables as:
when the displacement of the (i + 1) th node relative to the ith node is Δ x, the length of the 2 segments of optical cables is changed as follows:
the corresponding dependent variables are:
the strain difference formula is further simplified to obtain two fiber gratings l1iAnd l2iHas a differential strain of
Is simple and easy to obtain
Considering the actual situation of the fiber grating layout, the deformation Δ x of the node i +1 is extremely small, so it can be assumed that the node deformation Δ x is much smaller than the layout height h of the fiber grating, i.e. the node deformation Δ x is much smaller than the layout height h of the fiber grating
Δx＜＜h
Is simple and easy to obtain
According to the relation formula of the fiber grating strain and the wavelength, the above formula becomes:
in the formula, k is a fiber bragg grating strain sensitivity coefficient, the detection of relative deformation between nodes can be realized by detecting the change of the wavelength of a fiber bragg grating array, the strain detection precision of the fiber bragg grating can reach pm level, and the high-precision deformation detection is realized by adjusting the sizes of h and li;
according to the above result, the position of the ith node is:
the absolute deformation of the ith node is as follows:
in the monitoring range of the fiber bragg grating array, nodes are selected at intervals to fix the absolute deformation of the nodes, the nodes are used as reference nodes, and the absolute deformation of each node in the monitoring universe range of the array fiber bragg grating can be realized through the above formula;
the fiber grating demodulation instrument scans the central wavelength of each fiber grating of the fiber grating array sensor in real time, transmits the wavelength data to the data processing unit through the communication interface, and realizes the real-time monitoring of the deformation of the array fiber grating monitoring universe range by utilizing the mapping relation of the wavelength and the deformation.
6. The full-time global online monitoring method for large engineering structure deformation according to claim 4, characterized in that: aiming at the existing large-scale project to be monitored, the method for fixing the fiber grating array optical cable on the structure to be monitored comprises the following steps: firstly, a line card is utilized to cross-lay and position the array grating strain sensing optical cable; and coating structural adhesive on the well-positioned array grating strain sensing optical cable, and additionally installing a cover plate for protection.
7. The full-time global online monitoring method for large engineering structure deformation according to claim 4, characterized in that: aiming at newly repaired large-scale engineering, the method for fixing the fiber grating array optical cable on the tested structure comprises the following steps: before the concrete is poured into the structure, the array grating strain sensing optical cables are arranged in a crossed mode and are poured into a whole with the concrete structure.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114264338A (en) * | 2021-12-29 | 2022-04-01 | 中铁第四勘察设计院集团有限公司 | BIM-based grating array track monitoring information visualization analysis method and system |
| CN114575927A (en) * | 2022-03-16 | 2022-06-03 | 武汉理工大学 | Rail transit safety monitoring system and method |
| CN114684217A (en) * | 2022-03-16 | 2022-07-01 | 武汉理工大学 | Rail transit health monitoring system and method |
| CN114894102A (en) * | 2022-05-24 | 2022-08-12 | 中铁第四勘察设计院集团有限公司 | Shield tunnel structure monitoring system and method based on array grating |
| CN116542146A (en) * | 2023-01-06 | 2023-08-04 | 中路高科交通检测检验认证有限公司 | Bridge monitoring temperature field-strain field space-time correlation model and health diagnosis method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004037423A (en) * | 2002-07-08 | 2004-02-05 | Airec Engineering Corp | Optical fiber strain sensor and strain measuring system using the sensor |
| JP2009294039A (en) * | 2008-06-04 | 2009-12-17 | Mie Univ | Structure deformation monitoring method using distribution type optical-fiber sensing system, and device thereof |
| WO2016000034A1 (en) * | 2014-06-30 | 2016-01-07 | Commonwealth Scientific And Industrial Research Organisation | Deformation measurement method and apparatus |
| CN207423666U (en) * | 2017-11-29 | 2018-05-29 | 湖北凯乐科技股份有限公司 | A kind of cable snatch test fixture |
| CN207946576U (en) * | 2018-03-14 | 2018-10-09 | 黄河科技学院 | A kind of communication cable fixation gold utensil |
| CN209310749U (en) * | 2019-03-09 | 2019-08-27 | 苏东仓 | A kind of monitoring concrete entirety freeze thawing expansion strain sensor |
-
2021
- 2021-05-24 CN CN202110566835.3A patent/CN113639646B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004037423A (en) * | 2002-07-08 | 2004-02-05 | Airec Engineering Corp | Optical fiber strain sensor and strain measuring system using the sensor |
| JP2009294039A (en) * | 2008-06-04 | 2009-12-17 | Mie Univ | Structure deformation monitoring method using distribution type optical-fiber sensing system, and device thereof |
| WO2016000034A1 (en) * | 2014-06-30 | 2016-01-07 | Commonwealth Scientific And Industrial Research Organisation | Deformation measurement method and apparatus |
| CN207423666U (en) * | 2017-11-29 | 2018-05-29 | 湖北凯乐科技股份有限公司 | A kind of cable snatch test fixture |
| CN207946576U (en) * | 2018-03-14 | 2018-10-09 | 黄河科技学院 | A kind of communication cable fixation gold utensil |
| CN209310749U (en) * | 2019-03-09 | 2019-08-27 | 苏东仓 | A kind of monitoring concrete entirety freeze thawing expansion strain sensor |
Non-Patent Citations (2)
| Title |
|---|
| 信思金: "FBG传感技术在大坝安全监测中的应用研究", 武汉理工大学学报, no. 08 * |
| 闫奇众;蒋佩蓁;: "基于光纤光栅阵列的金属构件应力检测研究", 武汉理工大学学报, no. 01 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114264338A (en) * | 2021-12-29 | 2022-04-01 | 中铁第四勘察设计院集团有限公司 | BIM-based grating array track monitoring information visualization analysis method and system |
| CN114575927A (en) * | 2022-03-16 | 2022-06-03 | 武汉理工大学 | Rail transit safety monitoring system and method |
| CN114684217A (en) * | 2022-03-16 | 2022-07-01 | 武汉理工大学 | Rail transit health monitoring system and method |
| CN114684217B (en) * | 2022-03-16 | 2024-03-01 | 武汉理工大学 | Rail transit health monitoring system and method |
| CN114894102A (en) * | 2022-05-24 | 2022-08-12 | 中铁第四勘察设计院集团有限公司 | Shield tunnel structure monitoring system and method based on array grating |
| CN114894102B (en) * | 2022-05-24 | 2023-12-22 | 中铁第四勘察设计院集团有限公司 | Shield tunnel structure monitoring system and method based on array grating |
| CN116542146A (en) * | 2023-01-06 | 2023-08-04 | 中路高科交通检测检验认证有限公司 | Bridge monitoring temperature field-strain field space-time correlation model and health diagnosis method |
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