A grating array sensor layout method for bridge safety monitoring

Abstract

This invention relates to the field of bridge construction technology and discloses a method for deploying grating array sensors for bridge safety monitoring, comprising the following steps: confirming the deployment location and path of the grating array sensing optical cable at the bottom of the bridge; cleaning the bottom of the bridge along the deployment path to ensure the stability and reliability of subsequent grating array sensing optical cable deployment; bonding and fixing the grating array sensing optical cable to the bottom surface of the bridge according to the deployment path to achieve initial positioning and fixation of the grating array sensing optical cable; uniformly applying impregnating adhesive to both sides of the grating array sensing optical cable in the width direction to form a bonding interface between the grating array sensing optical cable and the bottom of the bridge; after completing the installation of the grating array sensing optical cables at various locations at the bottom of the bridge, connecting the same type of segmented grating array sensing optical cables in series to form a network; this invention, by attaching the optical cable to the bottom of the bridge, greatly improves the construction efficiency of optical cable installation and the stability and reliability of optical cable use.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method for deploying grating array sensors for bridge safety monitoring. Background Technology

[0002] In structural monitoring of small and medium-sized bridge groups, current engineering practices mostly employ discrete monitoring point deployment or single-point vibration sensor deployment. Discrete monitoring point deployment typically involves installing strain gauges or accelerometers at a few typical locations on the bridge to collect limited structural response data. While this method is simple to construct and low in cost, the limited number of sensor points makes it impossible to continuously reflect the stress and deformation state of the entire bridge area. The monitoring results suffer from insufficient representativeness and low spatial coverage, making it difficult to meet the unified monitoring needs of bridge groups.

[0003] In some studies, an embedded method has been attempted to deploy fiber optic grating array sensors in the bridge deck leveling layer. This method solves problems such as low coverage, discontinuous deployment, and poor signal coupling. However, it has shortcomings in terms of construction convenience, protective measures, and maintenance feasibility. Furthermore, the embedded deployment scheme has poor adaptability to the renovation of existing bridges, causes significant construction interference, and has high replacement and maintenance costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a method for deploying grating array sensors for bridge safety monitoring, thereby solving the technical problems of low construction convenience, complex protection measures, and difficulty in maintenance of grating array sensors in bridge safety monitoring in the prior art.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: This invention provides a method for deploying grating array sensors for bridge safety monitoring, comprising the following steps: S1. Confirm the location and path of the grating array sensing optical cable at the bottom of the bridge. S2. Clean the bottom of the bridge along the deployment path to ensure the stable and reliable deployment of the subsequent grating array sensing optical cable. S3. The grating array sensing optical cable is bonded and fixed to the bottom surface of the bridge according to the layout path to achieve the initial positioning and fixation of the grating array sensing optical cable. S4. Apply impregnating adhesive evenly to both sides of the grating array sensing optical cable in the width direction to form a bonding interface between the grating array sensing optical cable and the bottom of the bridge. S5. After completing the installation of the optical fiber grating array sensing cables at various locations at the bottom of the bridge, connect the same type of segmented optical fiber grating array sensing cables in series to form a network.

[0006] In some embodiments, in step S4, before the impregnating adhesive cures, a protective layer is covered on both sides of the grating array sensing optical cable along the laying path, and the protective layer is adhered and fixed to the bottom surface of the bridge using the impregnating adhesive to form a continuous protective layer.

[0007] In some embodiments, the impregnating adhesive comprises concrete structural adhesive; the protective layer comprises carbon fiber cloth.

[0008] In some embodiments, during the bonding and fixing process of the grating array sensing optical cable and the protective layer, compaction treatment needs to be carried out simultaneously.

[0009] In some embodiments, the cross-section of the grating array sensing optical cable perpendicular to its length direction is trapezoidal; the inclined surfaces of the trapezoids on both sides of the width of the grating array sensing optical cable abut against the impregnating adhesive and the protective layer.

[0010] In some embodiments, the grating array sensing optical cable includes sensing optical fiber, damping sleeve, aramid yarn and cable sheath sequentially arranged from the inside to the outside, and steel strand and steel wire reinforcing ribs are also provided inside the cable sheath along the width direction of the grating array sensing optical cable.

[0011] In some embodiments, in step S1, the placement location includes the side of the bottom of each box girder of the bridge near the center of the bridge; the placement path includes a straight line extending along the length of the bridge.

[0012] In some embodiments, step S2 includes the following steps: S21. Grind the joints between the various templates of the bridge and the uneven parts in the laying path to ensure the flatness of the laying path. S22. The bottom of the bridge is purged with gas along the layout path to complete the dust removal and drying process.

[0013] In some embodiments, in step S5, the optical fiber optic cables of the same type located on the left or right side of the bridge are connected in series to form a sensing link; the length of a single sensing link is no more than 5 kilometers.

[0014] In some embodiments, the grating array sensing optical cable includes a grating array vibration sensing optical cable, a grating array strain sensing optical cable, and a grating array temperature sensing optical cable. The spacing between the sensing probes inside the grating array sensing optical cable is 1 to 5 meters.

[0015] The grating array sensor deployment method for bridge safety monitoring provided in this embodiment of the invention has the following advantages compared to the prior art: By directly attaching and fixing the optical cable to the bottom of the bridge, the process of laying the cable is simplified while ensuring stable monitoring data. It eliminates the need for the traditional complex S-shaped laying path and the need for segmented laying for each bridge component. Furthermore, the cable can be laid at any stage after the bridge understructure construction is completed, making construction more flexible and the process simpler. In addition, it eliminates the need to cut grooves or pre-embed ducts in the bridge deck leveling layer, asphalt layer, or structural layer, avoiding any adverse effects on the integrity and structural safety of the bridge. Moreover, since the cable is laid at the bottom of the bridge, it also avoids damage during subsequent bridge construction, ensuring the cable's lifespan and operational stability. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the present invention; Figure 2 This is a cross-sectional view of the grating array sensing optical cable of the present invention; Figure 3 This is a simplified diagram of the installation position of the grating array sensing optical cable of the present invention.

[0017] In the diagram: 1. Grating array sensing optical cable; 11. Sensing optical fiber; 12. Damping sleeve; 13. Aramid yarn; 14. Cable sheath; 15. Steel strand; 16. Reinforcing rib; 2. Bridges; 21. Box girders; 3. Impregnating adhesive; 4. Protective layer. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, and are not used to describe a particular order, hierarchy, or importance of components.

[0020] It should be noted that, unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention. Furthermore, the use of terms such as "horizontal," "vertical," and "suspended" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, positioned in a specific orientation such as "horizontal," "vertical," or "suspended," can have an error / deviation of ±10% relative to that orientation, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still fulfill its function in the present invention.

[0021] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] In this application, "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0025] To address the technical problems of complex deployment processes, inflexible deployment times, and low lifespan and stability of existing grating array sensors used for bridge safety monitoring, this invention provides a method for deploying grating array sensors for bridge safety monitoring. This method simplifies the deployment process, improves the flexibility of deployment time, and enhances the lifespan and stability of the grating array sensors after deployment.

[0026] like Figures 1 to 3 As shown, a preferred embodiment of the present invention provides a method for deploying a grating array sensor for safety monitoring of bridge 2, which includes the following steps: S1. Confirm the location and path of the grating array sensing optical cable 1 at the bottom of the bridge 2. S2. Clean the bottom of bridge 2 along the deployment path to ensure the stable and reliable deployment of the subsequent grating array sensing optical cable 1. S3. The grating array sensing optical cable 1 is bonded and fixed to the bottom surface of the bridge 2 according to the layout path to achieve the initial positioning and initial fixation of the grating array sensing optical cable 1. S4. Apply impregnating adhesive 3 evenly to both sides of the grating array sensing optical cable 1 in the width direction so that the grating array sensing optical cable 1 forms a bonding interface at the bottom of the bridge 2. S5. After completing the installation of the optical fiber grating array sensing cables 1 at various locations at the bottom of bridge 2, connect the same type of segmented optical fiber grating array sensing cables 1 in series to form a network.

[0027] Specifically, in this embodiment, the grating array sensing optical cable 1 is laid out at the bottom of the bridge 2, which greatly avoids damage to the grating array sensing optical cable 1 during subsequent construction and use due to the movement of personnel and construction equipment on the bridge deck. This significantly improves the service life and stability of the grating array sensing optical cable 1, while also reducing losses and costs during installation. During the actual confirmation process, the installation personnel mark the installation path according to the construction drawings to facilitate subsequent installation work. Once the installation location and path are determined, the path needs to be cleaned beforehand to ensure that the surface is dry, flat, free of dust, oil, and loose particles. This ensures the stability of the subsequent application of the grating array sensing optical cable and, consequently, the quality of signal detection. After the deployment path is cleared, the grating array sensing optical cable can be laid. Along the pre-marked path, the high-strength adhesive on the grating array sensing optical cable is used to directly bond and fix it to the bottom surface of bridge 2, achieving positioning and installation of the grating array sensing optical cable. However, the high-strength adhesive on the back of the grating array sensing optical cable 1 alone is insufficient to maintain a long-term fit between the grating array sensing optical cable 1 and the bottom surface of bridge 2. Over time, the grating array sensing optical cable 1 may detach from the bottom of bridge 2, leading to unstable monitoring signals. Therefore, further reinforcement of the grating array sensing optical cable 1 is necessary. In this embodiment, impregnating adhesive 3 is applied to both sides of the grating array sensing optical cable along its length in the width direction, further fixing the grating array sensing optical cable to the bottom surface of bridge 2, preventing detachment, ensuring stable adhesion of the grating array sensing optical cable to the bottom surface of bridge 2, and thus ensuring stable monitoring signals. Once all the grating array sensing optical cables at the bottom of Bridge 2 are installed and fixed, the segmented grating array sensing optical cables 1 of the same type can be connected in series to form a network. The grating array sensing optical cables 1 are divided into multiple types depending on the monitored signal; therefore, different types of grating array sensing optical cables 1 need to be connected in series separately. In the actual deployment process, different types of grating array sensing optical cables 1 can be laid separately on different deployment paths, or multiple different types of grating array sensing optical cables 1 can be aggregated together and laid on a single deployment path, and then connected in series with the same type of grating array sensing optical cable 1 during the network connection stage.

[0028] It is understandable that during the installation of the grating array sensing optical cable 1, the laying alignment of the grating array sensing optical cable 1 should be strictly controlled to ensure it remains straight, continuous, and uniformly transitioned, preventing problems such as edge curling, bulging, and localized detachment, thus ensuring the quality of the installation. Simultaneously, a 1-2 meter length should be left at the installation end of the grating array sensing optical cable 1 for free movement, facilitating the interconnection and networking of grating array sensing optical cables 1.

[0029] It is understandable that after the grating array sensing optical cable 1 is laid out and connected in series, the entire sensing link needs to be tested to ensure that the entire sensing link can transmit signals completely without any breaks. Only then is the laying of the grating array sensing optical cable 1 completely completed.

[0030] It should be noted that during the process of confirming the deployment path, cleaning the deployment path, and deploying the grating array sensing optical cable, the relevant personnel all rode the bridge 2 inspection vehicle to the corresponding position at the bottom of the bridge 2 to confirm the deployment path, clean the deployment path, and deploy the grating array sensing optical cable 1.

[0031] In one embodiment, in step S4, before the impregnating adhesive 3 is cured, a protective layer 4 is covered on both sides of the grating array sensing optical cable 1 along the laying path in the width direction, and the protective layer 4 is glued and fixed to the bottom surface of the bridge 2 using the impregnating adhesive 3 to form a continuous protective layer 4.

[0032] Specifically, after the grating array sensing optical cable is completely fixed to the bottom surface of the bridge 2, it is still exposed to the external environment. Erosion and liquid corrosion in the external environment can damage the cable and affect the adhesion of the adhesive and impregnating agent 3. Therefore, in this embodiment, a protective layer 4 is also applied to the grating array sensing optical cable. This protective layer 4 is applied directly to the impregnating agent 3 and the grating array sensing optical cable before the adhesive 3 cures. After the impregnating agent 3 has completely cured, the protective layer 4 is firmly fixed to both. This protective layer 4 prevents external liquids from penetrating into the impregnating agent 3 and the surface of the grating array sensing optical cable, thus preventing damage to both and ensuring the stability of the grating array sensing optical cable's position and signal transmission.

[0033] Of course, it is understandable that during the subsequent maintenance phase, when it is necessary to replace a damaged section of the grating array sensing optical cable, the original protective layer 4 and impregnation 3 need to be removed first, then the damaged grating array sensing optical cable needs to be disassembled, and a new grating array sensing optical cable needs to be replaced in series. After that, the impregnation 3 is applied again and the protective layer 4 is covered.

[0034] It should also be noted that after the grating array sensing optical cables are deployed, they need to be connected in series to form a network, and the monitoring signals need to be tested to ensure that all grating array sensing optical cables are intact and the signal transmission is stable. In another specific embodiment, between steps S3 and S4, after all the grating array sensing optical cables are initially fixed with adhesive, segmented grating array sensing optical cables of the same type can be connected in series to test whether the signal transmission is good, and any grating array sensing optical cables that are damaged or have unstable signal transmission during the deployment process can be replaced in a timely manner. After it is confirmed that the signal transmission of all grating array sensing optical cables is stable, impregnating adhesive 3 can be applied to both sides of the grating array sensing optical cables and a fixing protective layer 4 can be applied to completely fix the grating array sensing optical cables. Then the grating array sensing optical cables are networked.

[0035] In another embodiment, signal testing can be performed individually on each segment of the grating array sensing optical cable. That is, after the grating array sensing optical cable of a segment is initially fixed with adhesive, the testing equipment is used to test the segment of the grating array sensing optical cable. Once the signal transmission of the segment of the grating array sensing optical cable is found to be stable, it indicates that the deployment of the segment of the grating array sensing optical cable is in good condition. After taking protective measures for the segment of the grating array sensing optical cable, the deployment of the next segment of the grating array sensing optical cable can be carried out. After all segments of the grating array sensing optical cable are deployed, the impregnating adhesive 3 can be coated and the protective layer 4 can be covered and fixed uniformly.

[0036] In other embodiments, the deployment of multiple grating array sensing optical cables can be carried out simultaneously. For example, when deploying multiple parallel grating array sensing optical cables for different segments on one side of bridge 2, multiple workers can ride on the bridge 2 inspection vehicle. Each worker deploys a different grating array sensing optical cable, and as the bridge 2 inspection vehicle moves along the length of bridge 2, the deployment of multiple parallel grating array sensing optical cables can be completed simultaneously. Then, the impregnation adhesive 3 and protective layer 4 are simultaneously applied to the multiple parallel grating array sensing optical cables. Furthermore, while the previous group of workers is laying the grating array sensing optical cables, another group of workers can ride in another bridge 2 inspection vehicle to simultaneously apply the impregnation adhesive 3 and apply the protective layer 4 behind the previous group of workers. This further reduces the deployment time of the grating array sensing optical cables.

[0037] In another embodiment, considering labor costs and construction safety, the cleaning of the deployment path, the initial fixing of the grating array sensing optical cable, and the application of the impregnating adhesive 3 and the covering of the protective layer 4 can also be carried out in staggered shifts. That is, when the first group of workers begins cleaning the deployment path of the second grating array sensing optical cable, the second group of workers can simultaneously begin the initial fixing of the first grating array sensing optical cable. And when the second group of workers begins the initial fixing of the second grating array sensing optical cable, the third group of workers can begin the application of the impregnating adhesive 3 and the covering of the protective layer 4 of the first grating array sensing optical cable, thereby improving the deployment efficiency of the grating array sensing optical cable.

[0038] In one embodiment, the impregnating adhesive 3 comprises concrete structural adhesive; the protective layer 4 comprises carbon fiber cloth.

[0039] Specifically, in this embodiment, the impregnating adhesive 3 is concrete structural adhesive, preferably carbon fiber structural adhesive. This improves the bending and shear resistance of the grating array sensing optical cable, ensuring its stability and reliability during subsequent use. The carbon fiber cloth, with its high strength, lightweight, and corrosion resistance, effectively prevents external corrosive gases or liquids from penetrating and damaging the impregnating adhesive 3. This protects both the impregnating adhesive 3 and the grating array sensing optical cable, ensuring the stability of the cable's position.

[0040] In one embodiment, during the bonding and fixing process of the grating array sensing optical cable 1 and the protective layer 4, compaction treatment needs to be carried out simultaneously.

[0041] Specifically, during the actual construction process, while laying the grating array sensing optical cable using the adhesive backing, workers also need to use a scraper mechanism to compact the cable to eliminate gaps and enhance adhesion between the cable and the bottom surface of bridge 2. During the application of the impregnating adhesive 3, in addition to controlling the uniformity of its thickness, continuous pressure can be applied to the cable before the adhesive cures to prevent air pockets or localized detachment. Similarly, during the application of the protective layer 4, to ensure a smooth and complete coverage, a scraper is used to compact the layer, enhancing the adhesion between the carbon fiber cloth, the grating array sensing optical cable, and the bottom surface of bridge 2. This process effectively improves the mechanical protection and environmental adaptability of the surface-mounted optical cable, ensuring long-term stable operation.

[0042] In this embodiment, the grating array sensing optical cable 1 is fully bonded to the bottom end of the bridge 2 and reinforced with carbon fiber cloth, which effectively avoids the signal attenuation and reflection instability problems caused by construction errors, uneven compaction, or structural layer deformation in traditional buried installations. This method significantly improves the stability and consistency of the sensing signal, ensuring long-term reliability of monitoring data.

[0043] In another specific embodiment, the scraper mechanism can be a base plate with rollers. Two clamps are spring-loaded at the bottom of the base plate, clamping the two inclined sides of the grating array sensing optical cable 1 in the width direction. A scraper is connected to the tail of the base plate via a spring, pressing against the top of the grating array sensing optical cable 1. The worker only needs to guide the base plate and the grating array sensing optical cable 1 at the front end, and the scraper, under the pressure of the spring, can press and fix the grating array sensing optical cable 1 firmly onto the laying path at the bottom end face of the bridge 2, greatly improving the laying efficiency of the grating array sensing optical cable 1. Furthermore, a winding shaft can be provided at the front end of the base plate. The winding shaft and rollers are linked by gears. When the rollers rotate, causing the base plate to move along the laying path, the winding shaft rotates, winding up the protective paper of the adhesive backing of the grating array sensing optical cable 1 to expose the adhesive backing, thus facilitating the initial fixation of the grating array sensing optical cable 1.

[0044] In one embodiment, the cross-section of the grating array sensing optical cable 1 perpendicular to its length direction is trapezoidal; the inclined surfaces of the trapezoids on both sides of the width of the grating array sensing optical cable 1 abut against the impregnating adhesive 3 and the protective layer 4.

[0045] Specifically, in this embodiment, the grating array sensing optical cable 1 has an overall elongated trapezoidal structure, with the width of its upper end face being smaller than the width of its lower end face. This results in the two sides of the grating array sensing optical cable 1 being inclined surfaces in the width direction. During actual deployment, the wider lower end face of the grating array sensing optical cable 1 is fitted against the bottom end face of the bridge 2, which increases the contact area between the grating array sensing optical cable 1 and the bottom end face of the bridge 2, allowing the sensors inside the grating array sensing optical cable 1 to better monitor the status of the bridge 2.

[0046] The inclined surfaces on both sides of the grating array sensing optical cable 1 can form a bonding interface with the impregnating adhesive 3. The impregnating adhesive 3 transitions naturally from the inclined surface of the grating array sensing optical cable 1 to the bottom end face of the bridge 2. The impregnating adhesive 3 at the junction of the grating array sensing optical cable 1 and the bottom end face of the bridge 2 is continuous and smooth, with natural and large corners, thus more firmly fixing the grating array sensing optical cable 1 to the bottom end face of the bridge 2. The position of the grating array sensing optical cable 1 is more secure and reliable. Furthermore, when the carbon fiber cloth covers the grating array sensing optical cable 1, its corners are also more natural, resulting in better adhesion between the carbon fiber cloth and the grating array sensing optical cable 1. This gives the grating array sensing optical cable 1 better fatigue resistance and aging resistance, effectively extending the service life of the sensor and meeting the requirements of long-term service.

[0047] In one embodiment, the grating array sensing optical cable 1 includes sensing optical fiber 11, damping sleeve 12, aramid yarn 13 and cable sheath 14 arranged sequentially from the inside to the outside. The cable sheath 14 is further provided with steel strand 15 and steel wire reinforcing rib 16 along the width direction of the grating array sensing optical cable 1.

[0048] Specifically, the cable sheath 14 effectively isolates external media such as moisture, dust, and oil, providing not only protection but also ensuring the stability of the cross-sectional structure of the grating array sensing optical cable 1, preventing deformation and unraveling. The steel wire reinforcing ribs 16 improve tensile strength, compressive strength, and resistance to lateral deformation, maintaining the stability of the cross-sectional geometry of the grating array sensing optical cable 1 and limiting excessive bending and flattening under external loads. The reinforcing ribs 16 also help maintain the straightness of the grating array sensing optical cable 1 during installation. The steel strands 15 further enhance tensile strength and structural stability. The aramid yarn 13 preferentially bears the load under tension, preventing excessive stretching of the optical fiber and protecting its transmission and sensing performance. The damping sleeve 12, wrapped around the sensing optical fiber 11, buffers external impacts, reduces local stress concentration, and suppresses damage caused by high-frequency stray vibrations or localized hard contacts, providing a relatively stable working environment for the optical fiber.

[0049] In one embodiment, in step S1, the placement location includes the side of the bottom of each box girder 21 of the bridge 2 near the center of the bridge 2; the placement path includes a straight line extending along the length of the bridge 2.

[0050] Specifically, in this embodiment, the grating array sensing optical cable 1 is laid on the bottom of the box girder 21 near the center of the bridge 2, which can better monitor the deformation state of the bridge 2. In a specific two-way six-lane bridge 2, four grating array sensing optical cables 1 are respectively set on the bottom of one side of the bridge 2, so as to monitor the state of the bridge 2 more comprehensively. The laying path is a straight structure, which does not require the traditional S-shaped complex laying path. Therefore, it is not necessary to carry out segmented laying for each section of the bridge 2 component. The grating array sensing optical cable 1 can be pasted along the bridge bottom in a straight path at any stage after the initial splicing of each box girder 21. The construction time is sufficient and is not limited by the bridge deck construction process and window period, which significantly improves the flexibility of the project implementation. Moreover, only the expansion allowance needs to be reserved at the expansion joint of the bridge 2 to cross, without additional welding or splicing nodes, reducing the number of singular points and welding points. This can significantly reduce the construction process, construction workload, the amount of grating array sensing optical cable 1 used, and the later maintenance costs, thereby improving construction efficiency.

[0051] In one embodiment, step S2 includes the following steps: S21. Grind the joints between the various templates of Bridge 2 and the uneven parts in the laying path to ensure the flatness of the laying path. S22. The bottom of bridge 2 is purged with gas along the layout path to complete the dust removal and drying process.

[0052] Specifically, during actual construction, the bottom surface of Bridge 2 often contains a lot of dust and other impurities, as well as protrusions. These impurities can affect the stability of the bonding state of the grating array sensing cable 1, making it easy for the grating array sensing cable 1 to detach from the bonding state with Bridge 2. The protrusions, on the one hand, can also damage the bonding state of the grating array sensing cable 1; on the other hand, they can also seriously affect the adhesion between the grating array sensing cable 1 and the bottom surface of Bridge 2, thus preventing the grating array sensing cable 1 from accurately monitoring the temperature and deformation state of Bridge 2. Therefore, when cleaning the deployment path, the bottom surface of bridge 2 needs to be leveled first. This can be done by first sanding the bottom surface of bridge 2 along the deployment path with sandpaper or a grinding wheel, then using a flatness testing instrument to check the flatness of the bottom surface of bridge 2 along the deployment path. Based on the test results, the deployment path is then sanded and leveled again. Once the flatness of the bottom surface of bridge 2 meets the deployment requirements of the grating array sensing optical cable 1, gas purging can begin along the deployment path to remove dust, oil, water stains, and other impurities. In a specific embodiment, high-temperature, high-pressure gas combined with an air gun can be used to purge along the deployment path, thereby removing impurities more efficiently.

[0053] In one embodiment, in step S5, the optical fiber optic cables of the same type located on the left or right side of the bridge 2 are connected in series to form a sensing link; the length of a single sensing link is no more than 5 kilometers.

[0054] Furthermore, the grating array sensing optical cable 1 includes a grating array vibration sensing optical cable, a grating array strain sensing optical cable, and a grating array temperature sensing optical cable. The spacing between the internal sensing probes of the grating array sensing optical cable 1 is 1 to 5 meters.

[0055] Specifically, in practical use, the grating array sensing optical cable 1 is divided into three types based on the different internal sensors and monitored signals: grating array vibration sensing optical cable, grating array strain sensing optical cable, and grating array temperature sensing optical cable. These three types of grating array sensing optical cables 1 are used to monitor the vibration state, strain state, and temperature state of the bridge 2, respectively. These three grating array sensing optical cables 1 can be deployed separately or together. They only need to be networked separately during the serial networking stage, thereby enabling comprehensive monitoring of the bridge 2's state. In a specific embodiment, the spacing between vibration sensors within the vibration sensing optical cable ranges from 3 meters to 5 meters, while the spacing between sensors within the strain sensing optical cable and temperature sensing optical cable ranges from 1 meter to 2 meters.

[0056] In actual construction, demodulation capability affects the length of the link. Therefore, the length of the sensor link needs to be controlled during deployment to avoid signal instability and other problems, and to ensure the stability and reliability of the subsequent use of the grating array sensor optical cable 1.

[0057] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A method for deploying grating array sensors for bridge safety monitoring, characterized in that, Includes the following steps: S1. Confirm the location and path of the grating array sensing optical cable at the bottom of the bridge. S2. Clean the bottom of the bridge along the deployment path to ensure the stable and reliable deployment of the subsequent grating array sensing optical cable. S3. The grating array sensing optical cable is bonded and fixed to the bottom surface of the bridge according to the layout path to achieve the initial positioning and fixation of the grating array sensing optical cable. S4. Apply impregnating adhesive evenly to both sides of the grating array sensing optical cable in the width direction to form a bonding interface between the grating array sensing optical cable and the bottom of the bridge. S5. After completing the installation of the optical fiber grating array sensing cables at various locations at the bottom of the bridge, connect the same type of segmented optical fiber grating array sensing cables in series to form a network.

2. The method for deploying grating array sensors for bridge safety monitoring according to claim 1, characterized in that, In step S4, before the impregnating adhesive cures, a protective layer is covered on both sides of the grating array sensing optical cable along the laying path, and the protective layer is glued and fixed to the bottom surface of the bridge to form a continuous protective layer.

3. The method for deploying grating array sensors for bridge safety monitoring according to claim 2, characterized in that, The impregnating adhesive includes concrete structural adhesive; the protective layer includes carbon fiber cloth.

4. The method for deploying grating array sensors for bridge safety monitoring according to claim 3, characterized in that, During the bonding and fixing process of the grating array sensing optical cable and the protective layer, compaction treatment needs to be carried out simultaneously.

5. The method for deploying grating array sensors for bridge safety monitoring according to claim 3, characterized in that, The cross-section of the grating array sensing optical cable perpendicular to its length direction is trapezoidal; the inclined surfaces of the trapezoids on both sides of the width of the grating array sensing optical cable abut against the impregnating adhesive and the protective layer.

6. The method for deploying grating array sensors for bridge safety monitoring according to claim 5, characterized in that, The grating array sensing optical cable includes sensing optical fiber, damping sleeve, aramid yarn and cable sheath arranged sequentially from the inside to the outside. The cable sheath is also provided with steel strand and steel wire reinforcing ribs along the width direction of the grating array sensing optical cable.

7. The method for deploying grating array sensors for bridge safety monitoring according to claim 1, characterized in that, In step S1, the placement location includes the side of the bottom of each box girder of the bridge near the center of the bridge; the placement path includes a straight line extending along the length of the bridge.

8. The method for deploying grating array sensors for bridge safety monitoring according to claim 1, characterized in that, Step S2 includes the following steps: S21. Grind the joints between the various templates of the bridge and the uneven parts in the laying path to ensure the flatness of the laying path. S22. The bottom of the bridge is purged with gas along the layout path to complete the dust removal and drying process.

9. The method for deploying grating array sensors for bridge safety monitoring according to claim 1, characterized in that, In step S5, the optical fiber optic cables of the same type located on the left or right side of the bridge are connected in series to form a sensing link; the length of a single sensing link is no more than 5 kilometers.

10. The method for deploying grating array sensors for bridge safety monitoring according to claim 1, characterized in that, The grating array sensing optical cable includes a grating array vibration sensing optical cable, a grating array strain sensing optical cable, and a grating array temperature sensing optical cable. The spacing between the sensing probes inside the grating array sensing optical cable is 1 to 5 meters.

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