Self-sensing fabricated ballastless track structure and construction method

Abstract

The invention provides a self-sensing assembly type ballastless track structure and a construction method, the self-sensing assembly type ballastless track structure comprises a plurality of ballastless tracks, and each ballastless track comprises a track plate. A plurality of first limiting holes are formed in the middle of the track plate, every two adjacent first limiting holes are communicated through a first groove, the bottom plate is arranged below the track plate and comprises a plurality of limiting bosses, each limiting boss is contained in the corresponding first limiting hole, and a containing space is reserved between the outer wall of each limiting boss and the inner wall of the corresponding first limiting hole. The optical cable comprises a grating array temperature sensing optical cable, and the grating array temperature sensing optical cable enters the first containing space from the position between the track plate and the bottom plate, extends into the first groove and then goes out of the track plate and the bottom plate through the second containing space. The fiber bragg grating temperature sensing optical cable and the ballastless track structure are integrally designed and constructed, and full-time, full-domain and full-period monitoring in the construction and operation process is achieved.

Description

Technical Field

[0001] The present invention relates to the field of rail transit technology, and in particular to a self-sensing assembled ballastless track structure and a construction method. Background Art

[0002] Prefabricated ballastless track has been widely used in recent years because of its advantages such as good smoothness, good stability, long service life, good durability, and less maintenance work. However, affected by complex climate and geological environment, natural disasters, etc., the track structure will have structural deformations such as arching and lateral displacement, which will affect the stability and durability of the track structure, and threaten operational safety in severe cases. Therefore, long-term monitoring of the track structure is required. Traditional contact monitoring equipment is installed on the track structure at a later stage, with many on-site equipment and wiring. To ensure safety, long-term inspections and maintenance are required. Non-contact monitoring methods, such as image recognition, avoid direct contact with the track structure, but the monitoring accuracy is not as good as contact monitoring, and the cost is higher.

[0003] Array grating technology is a new generation of fiber optic sensing technology. The sensing optical cable has the characteristics of wide monitoring coverage (≥10km), high measurement accuracy (1dB), and small sensor unit spacing (the minimum can be 1cm). However, the track monitoring structures that currently use array grating technology are installed during operation. First, it cannot realize monitoring during the construction process. Second, the field equipment and lines installed on the track structure later are temporary structures, which poses operational risks. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a self-sensing prefabricated ballastless track structure and a construction method, which integrates the design and construction of a fiber grating array temperature sensing cable with a new prefabricated ballastless track structure, ensuring that the fiber grating temperature sensing cable is closely integrated with the prefabricated ballastless track structure, while achieving full-time, full-domain and full-cycle monitoring during construction and operation, and comprehensively grasping the health status of the track structure in real time, so as to guide the engineering department to promptly inspect, maintain and warn the ballastless track.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A self-sensing assembled ballastless track structure, comprising:

[0007] A plurality of ballastless tracks assembled in sequence, wherein each ballastless track comprises:

[0008] A track plate, the top of which is used for train running, a plurality of first limiting holes arranged at a certain distance are arranged in the middle of the track plate, and two adjacent first limiting holes are connected through a first groove;

[0009] A bottom plate, arranged below the track plate, comprising a plurality of limiting bosses arranged at a certain distance, each limiting boss being accommodated in a first limiting hole, and an accommodation space being reserved between an outer wall of the limiting boss and an inner wall of the first limiting hole;

[0010] The optical cable includes a grating array temperature sensing optical cable, wherein the grating array temperature sensing optical cable enters into a first accommodating space from between the track plate and the base plate and extends into the first groove, and then comes out of the track plate and the base plate through a second accommodating space, the first accommodating space and the second accommodating space are arranged adjacent to each other, and the grating array temperature sensing optical cables are arranged in a plurality of "X" shapes.

[0011] Furthermore, the optical cable also includes at least one monitoring sensor optical cable, and the track plate is also provided with at least one second groove, the second groove is dug along the extension direction of the track plate, and the monitoring sensor optical cables are arranged in the second groove one by one.

[0012] Furthermore, the monitoring sensing optical cable includes a grating array vibration sensing optical cable and a grating array stress sensing optical cable, and a second groove is respectively arranged on both sides of the track plate, and the grating array vibration sensing optical cable and the grating array stress sensing optical cable are respectively arranged in two second grooves in a one-to-one correspondence, and the grating array vibration sensing optical cable and the grating array stress sensing optical cable are evenly provided with equally spaced sensors, and the grating array vibration sensing optical cable, the grating array stress sensing optical cable and the grating array temperature sensing optical cable are all continuous fiber grating array optical cables.

[0013] Furthermore, the inner wall of the first groove and the inner wall of the second groove are both roughened or chiseled to maintain a certain degree of roughness.

[0014] Furthermore, both the first groove and the second groove are provided with grouting holes.

[0015] Further, the first limiting hole is a square hole, the first limiting hole has a circular chamfer, the limiting boss is a square boss, the accommodating space is a mouth-shaped groove, one end of the first groove is connected to the first mouth-shaped groove, and the other end is connected to the second mouth-shaped groove, and the first mouth-shaped groove and the second mouth-shaped groove are arranged adjacent to each other.

[0016] Furthermore, it also includes an elastic buffer cover, which includes an elastic buffer bottom plate, a sleeve and reinforcing ribs, the sleeve is fixed on the bottom of the elastic buffer bottom plate, and a plurality of reinforcing ribs are arranged on the inner side of the sleeve. The elastic buffer cover is arranged on the first limiting hole to seal the accommodating space, the elastic buffer bottom plate cover is arranged on the top of the first limiting hole, the sleeve is clamped in the accommodating space, and the reinforcing ribs are pressed against the limiting boss.

[0017] Furthermore, it also includes a flexible pad, which is arranged between the bottom of the track plate and the top of the base plate, and the flexible pad is provided with a plurality of second limiting holes arranged at a certain distance, each of the second limiting holes corresponds to a position of the first limiting hole, and the limiting boss passes through the second limiting hole.

[0018] Furthermore, the track plate is pre-implanted with a radio frequency identification chip.

[0019] A construction method of a self-sensing assembled ballastless track structure, applied to the above-mentioned self-sensing assembled ballastless track structure, comprises the following steps:

[0020] A prefabricated track plate, wherein the track plate has a plurality of first limiting holes arranged at a certain distance, and a first groove is made between two adjacent first limiting holes;

[0021] After the prefabricated track slab is transported to the construction site, connectors or gate-shaped bars are embedded or implanted on the lower foundation surface of the track slab on site, and the steel mesh of the self-compacting concrete layer is arranged at the same time;

[0022] The track plate 1 is fixed and roughly laid to the corresponding position by a fixing tool, and the grating array temperature sensor optical cable is installed to the designated position. The designated position is that the grating array temperature sensor optical cable enters the first accommodation space from between the track plate and the bottom plate and extends into the first groove, and then comes out of the track plate and the bottom plate through the second accommodation space. The grating array temperature sensor optical cable is in the shape of a number of "X"s connected in sequence, and the track plate is finely adjusted;

[0023] Install formwork around the bottom of the track slab to prevent leakage when pouring self-compacting concrete;

[0024] Self-compacting concrete is poured from one of the limiting holes of the track plate. The concrete first fills the bottom of the track plate under the action of gravity to form a self-compacting concrete adjustment layer as the bottom plate. The concrete gradually rises and fills the first limiting hole to form a limiting boss. The other limiting hole of the track plate is used as an air outlet or observation hole. During grouting, the self-compacting concrete adjustment layer and the limiting boss are integrally poured and formed at one time.

[0025] The smooth first groove should be roughened to ensure the stability of the combination of new and old concrete, and the concrete surface should be smoothed. After the self-compacting concrete layer and the concrete in the first groove reach a certain strength, the track plate template and fixing tooling should be removed;

[0026] Secure the installed grating array temperature sensor optical cable and track plate, install the rails and fasteners on the track plate and retest.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] (1) The grating array temperature sensor cable is designed and constructed in an integrated manner with the new assembled ballastless track structure, and self-sensing monitoring of stress is achieved by installing the grating array temperature sensor cable. Under the premise of ensuring that the grating array temperature sensor cable is closely integrated with the new assembled ballastless track structure, full-time, full-domain, and full-cycle self-sensing monitoring of stress during construction and operation is achieved. This embodiment can conduct real-time and continuous monitoring of the temperature and change trend of the track structure system. The monitoring data is comprehensive, rich, and real-time effective, realizing the intelligent self-sensing function of the assembled track structure, and fully grasping the health status of the track structure in real time, so as to guide the engineering department to promptly inspect, maintain, and warn the ballastless track. The stress size and stress direction are in the shape of a "J", and the sensors are mainly concentrated in the vertical direction, so as to realize the monitoring of the temperature distribution at different depths of the ballastless track.

[0029] (2) The limiting boss is exposed and the limiting structure is explicitly limited. Routine inspections can promptly discover structural problems and ensure structural safety. The track plate of this embodiment is prone to deformation such as upward arching in the plate or warping at the four corners under the action of the temperature gradient load in the vertical direction of the plate thickness. Placing the grating array temperature sensor cable in the limiting groove is to be able to monitor the temperature distribution in the track plate in the vertical direction, thereby providing basic temperature data for subsequent analysis and evaluation of the deformation of the plate.

[0030] (3) Placing the grating array vibration sensor cable and the grating array temperature sensor cable on the side of the track plate makes subsequent maintenance relatively convenient. In combination with the grating array temperature sensor cable, different grating array sensor cables are installed to respectively monitor stress, temperature, and vibration. While ensuring that the fiber grating array sensor cable is closely integrated with the new assembled ballastless track structure, full-time, full-domain, and full-cycle monitoring of stress, temperature, and vibration during construction and operation is achieved, and the health status of the track structure is fully understood in real time to guide the engineering department to conduct timely inspection, maintenance, and early warning of the ballastless track.

[0031] (4) The self-compacting concrete layer is poured during on-site assembly to facilitate the leveling of the track plate; the cast-in-place self-compacting concrete fills the limiting holes of the track plate to form limiting bosses, which prevents the track plate from longitudinal and lateral displacement under external loads and ensures the overall stability of the structure; the self-compacting concrete layer is connected to the lower foundation through embedded parts or door-shaped reinforcements to form a stable force transmission system to transfer the force of the track structure to the lower foundation. The cast-in-place self-compacting concrete is combined with the groove in the middle of the track plate to fix the grating array temperature sensor cable. The first limiting hole of the track plate and the cast-in-place limiting boss adopt the "rectangular boss + circular chamfer" scheme, which combines the advantages of the circular boss that it is not easy to have stress concentration under the action of temperature load, and the advantages of the rectangular boss that it is uniformly stressed under the longitudinal and lateral loads of the train. At the same time, compared with the circular boss of the same size, the "square boss + circular chamfer" scheme has a stronger limiting ability and a more stable track structure.

[0032] (5) A layer of flexible pad is provided between the track plate and the base plate. The rubber pad under the plate can play the role of buffering, isolating, reducing vibration and adjusting height. When performing maintenance in the later stage, it is convenient to remove the plate due to the presence of the rubber pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0034] Figure 1 It is a schematic diagram of the overall structure of the self-sensing assembled ballastless track structure of the present invention;

[0035] Figure 2 It is an exploded view of the overall structure of the self-sensing assembled ballastless track structure of the present invention;

[0036] FIG3( a ) is a schematic diagram of a first groove scheme on a track plate of a self-sensing assembled ballastless track structure of the present invention;

[0037] FIG3( b ) is a schematic diagram of a second groove solution on the track plate of the self-sensing assembled ballastless track structure of the present invention;

[0038] FIG3( c ) is a schematic diagram of a second groove solution on the track plate of the self-sensing assembled ballastless track structure of the present invention;

[0039] Figure 4 It is a schematic diagram of the bottom plate of the self-sensing assembled ballastless track structure of the present invention;

[0040] Figure 5 It is a schematic diagram of an elastic buffer cover of a self-sensing assembled ballastless track structure of the present invention;

[0041] Figure 6It is a schematic diagram of the combination of the track plate and the optical cable of the self-sensing assembled ballastless track structure of the present invention;

[0042] Figure 7 It is a flow chart of the construction steps of the self-sensing assembled ballastless track structure of the present invention.

[0043] Among them, 1. track plate; 2. bottom plate; 3. flexible pad; 4. elastic buffer cover; 5. optical cable; 6. first groove; 7. first limiting hole; 8. second groove; 9. grouting hole; 10. second limiting hole; 11. limiting boss; 12. sleeve; 13. reinforcing rib; 14. elastic buffer bottom plate; 15. grating array stress sensing optical cable; 16. grating array vibration sensing optical cable; 17. grating array temperature sensing optical cable. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0046] Example 1

[0047] In the related art, the track monitoring structures using array grating technology are installed during operation, and cannot realize monitoring during the construction process. The field equipment and lines installed on the track structure later are temporary structures, which pose operational risks. This embodiment provides a self-sensing assembled ballastless track structure that integrates the fiber grating array temperature sensing cable 17 with the new assembled ballastless track structure for integrated design and integrated construction, which can realize monitoring during the construction process, is not a temporary structure, and does not pose operational risks.

[0048] Embodiment 1 provides a self-sensing assembled ballastless track structure, such as Figure 1-Figure 6 As shown, it comprises a plurality of ballastless tracks assembled in sequence.

[0049] Each ballastless track includes:

[0050] The track plate 1 has a top portion for train travel, and a plurality of first limiting holes 7 arranged at a certain distance are provided in the middle of the track plate 1, and two adjacent first limiting holes 7 are connected through a first groove 6;

[0051] The bottom plate 2 is arranged below the track plate 1, and includes a plurality of limiting bosses 11 arranged at a certain distance, each limiting boss 11 is accommodated in a first limiting hole 7, and an accommodation space is left between the outer wall of the limiting boss 11 and the inner wall of the first limiting hole 7;

[0052] The optical cable 5 includes a grating array temperature sensing optical cable 17. The grating array temperature sensing optical cable 17 enters the first accommodating space from between the track plate 1 and the base plate 2 and extends into the first groove 6, and then comes out of the track plate 1 and the base plate 2 through the second accommodating space. The first accommodating space and the second accommodating space are adjacent to each other, and the grating array temperature sensing optical cables 17 are arranged in a plurality of "X" shapes.

[0053] The present embodiment provides a self-sensing prefabricated ballastless track structure, which integrates the grating array temperature sensing optical cable 17 with the new prefabricated ballastless track structure in an integrated design and integrated construction, and realizes self-sensing monitoring of stress by installing the grating array temperature sensing optical cable 17. Under the premise of ensuring that the grating array temperature sensing optical cable 17 is closely integrated with the new prefabricated ballastless track structure, full-time, full-domain, and full-cycle self-sensing monitoring of temperature during construction and operation is realized. The present embodiment can conduct real-time and continuous monitoring of the temperature and change trend of the track structure system. The monitoring data is comprehensive, rich, and real-time effective, realizing the intelligent self-sensing function of the prefabricated track structure, and comprehensively grasping the health status of the track structure in real time, so as to guide the engineering department to timely inspect, maintain, and warn the ballastless track, and realize the monitoring of the temperature distribution at different depths of the ballastless track.

[0054] In addition, in this embodiment, the limiting boss 11 is exposed, and the limiting structure is explicitly limited. Daily inspections can timely discover structural problems and ensure structural safety. The track plate 1 in this embodiment is prone to deformation such as upward arching or warping of the four corners under the temperature gradient load in the vertical direction of the plate thickness. Placing the grating array temperature sensor cable 17 in the limiting groove is to be able to monitor the temperature distribution in the track plate 1 in the vertical direction, thereby providing basic temperature data for subsequent analysis and evaluation of the deformation of the plate.

[0055] In this embodiment, the track slab 1 is a factory prefabricated slab, and the concrete grade is C40 when ordinary reinforced concrete structure is adopted; and the concrete grade is C60 when prestressed reinforced concrete structure is adopted.

[0056] In this embodiment, Figure 1-As shown in FIG3, the optical cable 5 also includes at least one monitoring sensor optical cable. At least one second groove 8 is provided on the side of the track plate 1. The monitoring sensor optical cables are arranged one by one in the second groove 8. During construction, the monitoring sensor optical cables are fixed to the track by pouring concrete into the second groove 8. Through multiple optical cables 5, all-time, all-domain, and all-cycle self-sensing monitoring of various parameters during construction and operation is carried out, and real-time continuous monitoring is carried out. The monitoring data is comprehensive, rich, and real-time effective, realizing the intelligent self-sensing function of the assembled track structure, and comprehensively grasping the health status of the track structure in real time, so as to guide the engineering department to timely inspect, maintain, and warn the ballastless track.

[0057] In this embodiment, the monitoring sensing optical cable includes a grating array vibration sensing optical cable 16 and a grating array stress sensing optical cable 15. A second groove 8 is provided on both sides of the track plate 1. The grating array vibration sensing optical cable 16 and the grating array temperature sensing optical cable 17 are respectively provided in two second grooves 8 in a one-to-one correspondence. The grating array vibration sensing optical cable 16 and the grating array stress sensing optical cable 15 are evenly provided with sensors at equal intervals. The grating array stress sensing optical cable 15, the grating array vibration sensing optical cable 16 and the grating array temperature sensing optical cable 17 are all continuous fiber grating array optical cables 5. The three optical cables 5 collect stress strain, temperature, and vibration information in real time, receive the stress strain information sent by the monitoring optical cable 5 through the fiber grating data demodulator, and demodulate it into a demodulation signal and send it to the background processor.

[0058] In this embodiment, the grating array stress sensing optical cable 15, the grating array vibration sensing optical cable 16 and the grating array temperature sensing optical cable 17 are integrated with the new assembled ballastless track structure in design and construction, and the optical cable installation interface is reserved on the prefabricated track plate 1. The stress, temperature and vibration monitoring are realized by installing different grating array sensing optical cables 5. While ensuring that the fiber grating array sensing optical cable 5 is closely integrated with the new assembled ballastless track structure, the full-time, full-domain and full-cycle monitoring of stress, temperature and vibration during construction and operation is realized, and the health status of the track structure is fully understood in real time, so as to guide the engineering department to timely detect, maintain and warn the ballastless track.

[0059] This embodiment introduces the second generation of optical fiber sensing technology - array grating sensing technology. The sensing optical cable 5 has the characteristics of wide monitoring coverage (≥10km), high measurement accuracy (1dB), and small spacing between sensing units (the minimum can be 1cm). According to the needs of on-site monitoring, grating array stress sensing optical cable 15 and vibration sensing optical cable 5 are equipped with equally spaced sensors. The grating array temperature sensing optical cable 17 is in the shape of a "J", and the sensors are mainly concentrated in the vertical direction, which is convenient for monitoring the temperature distribution of ballastless track at different vertical depths.

[0060] In this embodiment, the optical cable installation interface is reserved on the prefabricated track plate 1 by prefabricating semicircular grooves on both sides and in the middle of the track plate 1 .

[0061] In this embodiment, Figure 3(a)-Figure 3(c) As shown, it is convenient to install the grating array stress sensing optical cable 15 and the grating array vibration sensing optical cable 16. During construction, the optical cable 5 is fixed to the track by pouring concrete into the slots. The slots on both sides of the track plate 1 can be located on the top, side, bottom and middle of the plate, and can be reasonably selected according to specific conditions.

[0062] In this embodiment, the inner wall of the first groove 6 and the inner wall of the second groove 8 are roughened or chiseled to maintain a certain degree of roughness, so as to ensure the stability of the joint surface between the new and old concrete when pouring concrete into the groove later. If the second groove 8 is set on the side, bottom, or middle of the track plate 1, a small grouting hole 9 should also be opened at the corresponding position of the second groove 8 of the track plate 1 to facilitate grouting and filling to fix the monitoring sensor optical cable.

[0063] In this embodiment, Figure 1-Figure 6 As shown, the first limiting hole 7 is a square hole, the first limiting hole 7 has a circular chamfer, the limiting boss 11 is a square boss, the accommodating space is a mouth-shaped groove, one end of the first groove 6 is connected to the first mouth-shaped groove, and the other end is connected to the second mouth-shaped groove, and the first mouth-shaped groove is adjacent to the second mouth-shaped groove. The limiting boss 11 and the bottom plate 2 are formed by cast-in-place self-compacting concrete, and the "rectangular boss + circular chamfer" scheme is adopted, which combines the advantages of the circular boss that it is not easy to have stress concentration under the action of temperature load, and the advantages of the rectangular boss that it is uniformly stressed under the longitudinal and lateral loads of the train. At the same time, compared with the circular boss of the same size, the "square boss + circular chamfer" scheme has a stronger limiting ability and a more stable track structure.

[0064] In this embodiment, Figure 1 and Figure 5 As shown, it also includes an elastic buffer cover 4, which includes an elastic buffer bottom plate 14, a sleeve 12 and reinforcing ribs 13. The sleeve 12 is fixed to the bottom of the elastic buffer bottom plate 14, and a plurality of reinforcing ribs 13 are arranged on the inner side of the sleeve 12. The elastic buffer cover 4 is arranged on the first limiting hole 7 to seal the accommodating space. The elastic buffer bottom plate 14 is arranged on the top of the first limiting hole 7. The sleeve 12 is stuck in the accommodating space, and the reinforcing ribs 13 are pressed against the limiting boss 11. The elastic buffer cover 4 is prefabricated in an integrated manner with the track plate 1 in the factory. When the track plate 1 is prefabricated, it has been installed at the first limiting hole 7 on the track plate 1, avoiding the problem of insufficient precision of the elastic buffer cushion layer in the later installation. The elastic buffer cushion layer is in the shape of a sleeve 12, and the ribbed structure on the outer surface ensures that the elastic buffer cushion layer is tightly combined with the prefabricated track plate 1.

[0065] In this embodiment, Figure 1 and Figure 2As shown, the flexible pad 3 is also included, and the flexible pad 3 is arranged between the bottom of the track plate 1 and the top of the bottom plate 2. The flexible pad 3 is provided with a plurality of second limiting holes 10 arranged at a certain distance, each second limiting hole 10 corresponds to a first limiting hole 7, and the limiting boss 11 penetrates the second limiting hole 10. The flexible pad 3 has the functions of buffering and vibration reduction.

[0066] The flexible pad 3 is a layered structure of other polymer materials such as rubber or geotextile, and a second limiting hole 10 is opened in the middle at a position corresponding to the first limiting hole 7 of the track plate 1. During construction, the flexible pad 3 is first bonded to the bottom of the track plate 1 to form a whole.

[0067] In this embodiment, the track plate 1 is a prefabricated unit plate structure, and the track plate 1 is pre-implanted with a radio frequency identification (RFID) chip, which contains information such as the manufacturing and numbering of the track plate 1, thereby realizing informatization and standardized control of the entire production process.

[0068] In the specific implementation of this embodiment, the bottom plate 2 and the limiting boss 11 are cast by self-compacting concrete, the track plate 1 has two first limiting holes 7 spaced at a certain distance, the flexible pad 3 has two second limiting holes 10 spaced at a certain distance, and the bottom plate 2 is provided with two limiting bosses 11 spaced at a certain distance, and each first limiting hole 7 corresponds to a second limiting block and a limiting boss 11. During on-site construction, the bottom plate 2 and the limiting boss 11 are formed by continuously and integrally pouring self-compacting concrete through one of the first limiting holes 7 of the track plate 1, and the other second limiting hole 10 of the track plate 1 is used as an air outlet or observation hole.

[0069] The self-sensing assembled ballastless track structure is described in detail below through a specific implementation method of this embodiment. Figure 1-Figure 6 As shown, the main structure includes a track plate 1, a bottom plate 2, a flexible pad 3, an elastic buffer cover 4 and an optical cable 5. The track plate 1 is provided with a first limit hole 7, a first groove 6 and a grouting hole 9; the bottom plate 2 is provided with a limit boss 11; the elastic buffer cover 4 includes an elastic buffer bottom plate 14, a sleeve 12 and a reinforcing rib 13; the optical cable 5 includes a grating array stress sensing optical cable 15, a grating array vibration sensing optical cable 16 and a grating array temperature sensing optical cable 17.

[0070] The track plate 1 is a factory prefabricated unit flat plate structure, with two square first limiting holes 7 in the middle of the track plate 1, and the first limiting holes 7 are provided with circular chamfers. In this example, the track plate 11 is 3800mm long, 2500mm wide, and 200mm thick. The limiting hole is 500mm long, 500mm wide, and the chamfer radius is 100mm.

[0071] During the prefabrication process of the track plate 1, an RFID (radio frequency identification) chip identification device is implanted, and the device is tied to the steel bars of the track plate 1 when the track plate 1 is prefabricated. A semicircular first groove 6 is prefabricated between the two first limiting holes 7 of the track plate 1, and a semicircular second groove 8 is prefabricated on both sides of the track plate 1. The diameters of the first groove 6 and the second groove 8 are both 50 mm, and they run through the entire track plate 1. When the first groove 6 and the second groove 8 for installing the optical cable 5 are prefabricated, they should be roughened or chiseled in advance to maintain a certain degree of roughness, so as to facilitate the later pouring of concrete in the groove and ensure reliable connection between the new and old concrete bonding surfaces. If the second groove 8 for installing the optical cable 5 is set on the side or in the plate of the track plate 1, a grouting hole 9 with a diameter of 50 mm should also be opened on the track plate 1. This example takes the second groove 8 for installing the optical cable 5 as an example, where the second groove 8 is located on both sides of the track plate 1. The scheme where the second groove 8 is located on the top, bottom, and in the plate of the track plate 1 is shown in FIG. Figure 3(a)-Figure 3(c) shown.

[0072] The elastic buffer cover 4 includes an elastic buffer bottom plate 14, a sleeve 12 and a reinforcing rib 13. The elastic buffer cover 4 is made of rubber or other polymer materials and is formed in one step. The sleeve 12 plays a buffering role between the first limiting hole 7 and the limiting boss 11; the reinforcing rib 13 penetrates into the concrete of the track plate 1 to strengthen the connection with the track plate 1; the elastic buffer bottom plate 14 fixes the reinforcing rib 13 and the sleeve 12. The elastic buffer cover 4 is prefabricated in an integrated factory with the track plate 1. When the track plate 1 is prefabricated and poured with concrete, it has been installed at the first limiting hole 7 corresponding to the track plate 1 mold. The elastic buffer cover 4 is a chamfered rectangle with a length of 480mm, a width of 480mm, a chamfer radius of 100mm, and a thickness of 20mm.

[0073] The flexible pad 3 is a plate-like structure of rubber or other polymer materials, and two second limiting holes 10 are opened in the middle at the corresponding positions of the first limiting holes 7 of the track plate 1. The second limiting holes 10 are square chamfered holes. During construction, the flexible pad 3 is first bonded to the bottom of the track plate 1 to form a whole. The flexible pad 3 is 3800mm long, 2500mm wide, and 4mm thick.

[0074] A limiting boss 11 is provided on the bottom plate 2. During on-site construction, self-compacting concrete is poured through one of the first limiting holes 7 of the track plate 1 to form the bottom plate 2 and the limiting boss 11. The bottom plate 2 is 100 mm thick.

[0075] There are three optical cables 5, namely, grating array stress sensing optical cable 155, grating array vibration sensing optical cable 16 and grating array temperature sensing optical cable 17. All three optical cables 5 are continuous fiber grating array optical cables 5, and the optical cables 5 between different track plates 1 are continuous. The grating array stress sensing optical cable 15 and the grating array vibration sensing optical cable 16 are straight-line and installed at the second groove 8 on both sides of the track plate 1. The grating array temperature sensing optical cable 17 is in the shape of a "J", first passing through the bottom plate 2 at the bottom of the track, then passing through a first limiting hole 7, a part of which is located in the second groove 8 in the middle of the track plate 1, and then passing through another first limiting hole 7, and finally passing through the bottom plate 2 and the flexible pad 3 to connect to the next track plate 1. After the three optical cables 5 are installed, the first groove 6 and / or the second groove 8 of the track plate 1 are poured with concrete and smoothed. The diameter of the optical cable 5 is 10 to 20 mm. The three optical cables 5 collect stress, strain, temperature and vibration information in real time, and receive the stress and strain information sent by the optical cables 5 through the fiber grating data demodulator, and demodulate it into a demodulation signal and send it to the background processor.

[0076] Example 2

[0077] Embodiment 2 provides a construction method of a self-sensing assembled ballastless track structure, such as Figure 7 As shown, the self-sensing assembled ballastless track structure applied to the above-mentioned structure includes the following steps:

[0078] Step 1: prefabricate a track plate 1, wherein the track plate 1 has a plurality of first limiting holes 7 arranged at a certain distance, and manufacture a first groove 6 between two adjacent first limiting holes 7;

[0079] Step 2: After the prefabricated track slab 1 is transported to the construction site, connectors or gate-shaped bars are pre-buried or implanted on the lower foundation surface of the track slab 1 on site, and a steel mesh of the self-compacting concrete layer is arranged;

[0080] Step 3: Use a fixing tool to fix and roughly lay the track plate 1 to the corresponding position, and install the grating array temperature sensor optical cable 17 to the specified position. The specified position is that the grating array temperature sensor optical cable 17 enters the first accommodating space between the track plate 1 and the bottom plate 2 and extends into the first groove 6, and then comes out of the track plate 1 and the bottom plate 2 through the second accommodating space. The grating array temperature sensor optical cable 17 is arranged in a plurality of "X" shapes, and the track plate 1 is finely adjusted;

[0081] Step 4: Install formwork around the bottom of the track plate 1 to prevent leakage when pouring self-compacting concrete;

[0082] Step 5: pouring self-compacting concrete from one of the limiting holes of the track plate 1. The concrete first fills the bottom of the track plate 1 under the action of gravity to form a self-compacting concrete adjustment layer as the bottom plate 2. The concrete gradually rises and fills the first limiting hole 7 to form a limiting boss 11. The other limiting hole of the track plate 1 is used as an air outlet or observation hole. During grouting, the self-compacting concrete adjustment layer and the limiting boss 11 are integrally poured and formed at one time.

[0083] Step 6: The smooth first groove 6 should be roughened to ensure the stability of the combination of new and old concrete, and the concrete surface should be smoothed. After the self-compacting concrete layer and the concrete in the first groove 6 reach 90% strength, the template and fixing tool of the track plate 1 should be removed;

[0084] Step 7: Fix the installed grating array temperature sensor cable 17 and track plate 1, install the rails and fasteners on the track plate 1 and perform retest.

[0085] In step 1, when the track slab 1 is prefabricated, the RFID (radio frequency identification) chip is tied to the steel bars of the track slab 1, and the flexible pad 3 is fixed to the corresponding position of the limiting hole of the track slab 1 mold, and is prefabricated as a whole with the track slab 1. After the prefabricated track slab 1 is transported to the construction site, the flexible pad 3 is glued and fixed to the bottom of the track slab 1 on site.

[0086] In step 1, the optical cable 5 also includes at least one monitoring sensor optical cable, and at least one second groove 8 is provided on the side of the track plate 1, and the monitoring sensor optical cables are arranged one by one in the second groove 8. In step 6, the smooth second groove 8 should be roughened to ensure the stability of the combination of new and old concrete, and the concrete surface is smoothed. After the self-compacting concrete layer, the concrete in the first groove 6 and the second groove 8 reaches 90% strength, the template and fixing tool of the track plate 1 are removed.

[0087] In summary, the beneficial effects of the present invention are:

[0088] The present invention proposes a self-sensing assembled ballastless track structure and construction method. The fiber grating array sensor cable 5 is designed and constructed in an integrated manner with the new assembled ballastless track structure, and an optical cable installation interface is reserved on the prefabricated track plate 1. Self-sensing monitoring of stress, temperature, and vibration is achieved by installing different grating array sensor cables 5. Under the premise of ensuring that the fiber grating array sensor cable 5 is closely integrated with the new assembled ballastless track structure, full-time, full-domain, and full-cycle self-sensing monitoring of stress, temperature, and vibration during construction and operation is achieved. The present invention can conduct real-time and continuous monitoring of the stress magnitude, stress direction, and change trend of the track structure system, the distribution of the track temperature field, and the vibration conditions. The monitoring data is comprehensive, rich, and real-time effective, realizing the intelligent self-sensing function of the assembled track structure, and comprehensively grasping the health status of the track structure in real time, so as to guide the engineering department to conduct timely inspection, maintenance, and early warning of the ballastless track.

[0089] The present invention proposes a self-sensing assembled ballastless track structure and construction method, wherein the track plate 1 is a prefabricated unit plate structure. An RFID (radio frequency identification) chip identification device is implanted in the track plate 1 when it is prefabricated in the factory. The chip contains information such as the manufacturing and numbering of the track plate 1, thereby realizing informatization and standardized control of the entire production process.

[0090] The present invention proposes a self-sensing assembled ballastless track structure and construction method, in which an optical cable installation interface is reserved on a prefabricated track plate 1, and semicircular sensing optical cable 5 installation grooves are prefabricated on both sides and in the middle of the track plate 1. When the inner wall of the groove is prefabricated, it should be roughened or chiseled in advance to maintain a certain roughness, so as to facilitate the later pouring of concrete in the groove and ensure the reliable connection of the new and old concrete interface.

[0091] The self-sensing assembled ballastless track structure and construction method proposed in the present invention introduces the second-generation optical fiber sensing technology - array grating sensing technology. The sensing optical cable 5 has the characteristics of wide monitoring coverage (≥10km), high measurement accuracy (1dB), and small spacing between sensing units (the minimum can be 1cm). According to the needs of on-site monitoring, grating array stress sensing optical cable 15 and vibration sensing optical cable 5 are equipped with equally spaced sensors. The grating array temperature sensing optical cable 17 is in the shape of a "J", and the sensors are mainly concentrated in the vertical direction to realize the monitoring of temperature distribution at different depths of the ballastless track.

[0092] The present invention proposes a self-sensing assembled ballastless track structure and construction method. The elastic buffer layer of the track plate 1 at the limiting hole is in the shape of a ribbed sleeve 12, which is prefabricated in an integrated factory with the track plate 1. When the track plate 1 is prefabricated, it is installed at the limiting hole of the track plate 1, avoiding the problem of insufficient precision of the elastic buffer layer in the later installation. The ribbed structure on the outer surface of the sleeve 12 extends into the concrete of the prefabricated track plate 1, ensuring that the elastic buffer layer is tightly combined with the prefabricated track plate 1.

[0093] The present invention proposes a self-sensing assembled ballastless track structure and construction method. The self-compacting concrete layer is poured during on-site assembly to facilitate the leveling of the track plate 1. The cast-in-place self-compacting concrete fills the limiting holes of the track plate 1 to form limiting bosses 11 to prevent the track plate 1 from longitudinal and lateral displacement under external loads, thereby ensuring the overall stability of the structure. The self-compacting concrete layer is connected to the lower foundation through embedded parts or door-shaped ribs to form a stable force transmission system to transmit the force of the track structure to the lower foundation. The cast-in-place self-compacting concrete is combined with the groove in the middle of the track plate 1 to fix the grating array temperature sensing optical cable 17.

[0094] The present invention proposes a self-sensing assembled ballastless track structure and construction method. The first limiting hole 7 of the track plate 1 and the cast-in-place limiting boss 11 adopt a "rectangular boss + circular chamfer" scheme, which combines the advantages of the circular boss that it is not easy to have stress concentration under the action of temperature load, and the advantages of the rectangular boss that it is uniformly stressed under the longitudinal and lateral loads of the train. At the same time, compared with the circular boss of the same size, the "square boss + circular chamfer" scheme has a stronger limiting ability and a more stable track structure.

[0095] The present invention proposes a self-sensing assembled ballastless track structure and construction method. A layer of flexible pad 3 is provided between the track plate 1 and the base plate 2. The rubber pad under the plate can have the functions of buffering, isolation, vibration reduction and height adjustment. When performing maintenance in the later stage, it is convenient to remove the plate due to the presence of the rubber pad.

[0096] The present invention proposes a self-sensing assembled ballastless track structure and construction method, in which the limiting boss 11 is exposed and the limiting structure is explicitly limited. Routine inspections can promptly discover structural problems and ensure structural safety. The track plate 1 of this embodiment is prone to deformation such as upward arching or warping of the four corners under the action of the temperature gradient load in the vertical direction of the plate thickness. Placing the grating array temperature sensing optical cable 17 in the limiting groove is to be able to monitor the temperature distribution in the track plate 1 in the vertical direction, thereby providing basic temperature data for subsequent analysis and evaluation of the deformation of the plate.

[0097] The above embodiments are merely examples of the technical solutions of the present invention. The methods involved in the present invention are not limited to the contents described in the above embodiments, but are subject to the scope defined in the claims. Any modification, supplement or equivalent replacement made by a person skilled in the art based on the embodiment is within the scope of protection required by the claims of the present invention.

Claims

1. A self-sensing assembled ballastless track structure, characterized in that: include: A plurality of ballastless tracks assembled in sequence, wherein each ballastless track comprises: A track plate, the top of which is used for train running, a plurality of first limiting holes arranged at a certain distance are arranged in the middle of the track plate, and two adjacent first limiting holes are connected through a first groove; A bottom plate, arranged below the track plate, comprising a plurality of limiting bosses arranged at a certain distance, each limiting boss being accommodated in a first limiting hole, and an accommodation space being reserved between an outer wall of the limiting boss and an inner wall of the first limiting hole; The optical cable includes a grating array temperature sensing optical cable, wherein the grating array temperature sensing optical cable enters into a first accommodating space from between the track plate and the base plate and extends into the first groove, and then comes out of the track plate and the base plate through a second accommodating space, the first accommodating space and the second accommodating space are arranged adjacent to each other, and the grating array temperature sensing optical cables are arranged in a plurality of "X" shapes.

2. The self-sensing assembled ballastless track structure according to claim 1 is characterized in that: The optical cable also includes at least one monitoring sensor optical cable. The track plate is also provided with at least one second groove, the second groove is dug along the extension direction of the track plate, and the monitoring sensor optical cables are arranged in the second groove one by one.

3. The self-sensing assembled ballastless track structure according to claim 2 is characterized in that: The monitoring sensing optical cable includes a grating array vibration sensing optical cable and a grating array stress sensing optical cable. A second groove is respectively arranged on both sides of the track plate. The grating array vibration sensing optical cable and the grating array stress sensing optical cable are respectively arranged in two second grooves in a one-to-one correspondence. The grating array vibration sensing optical cable and the grating array stress sensing optical cable are both provided with equally spaced sensors. The grating array vibration sensing optical cable, the grating array stress sensing optical cable and the grating array temperature sensing optical cable are all continuous fiber grating array optical cables.

4. The self-sensing assembled ballastless track structure according to claim 2 is characterized in that: The inner wall of the first groove and the inner wall of the second groove are both roughened or chiseled to maintain a certain degree of roughness.

5. The self-sensing assembled ballastless track structure according to claim 2 is characterized in that: The first groove and the second groove are both provided with grouting holes.

6. The self-sensing assembled ballastless track structure according to claim 1 is characterized in that: The first limiting hole is a square hole, the first limiting hole has a circular chamfer, the limiting boss is a square boss, the accommodating space is a mouth-shaped groove, one end of the first groove is connected to the first mouth-shaped groove, and the other end is connected to the second mouth-shaped groove, and the first mouth-shaped groove is adjacent to the second mouth-shaped groove.

7. The self-sensing assembled ballastless track structure according to claim 1 is characterized in that: It also includes an elastic buffer cover, which includes an elastic buffer bottom plate, a sleeve and reinforcing ribs, the sleeve is fixed to the bottom of the elastic buffer bottom plate, a plurality of reinforcing ribs are arranged on the inner side of the sleeve, the elastic buffer cover is arranged on the first limiting hole to seal the accommodating space, the elastic buffer bottom plate cover is arranged on the top of the first limiting hole, the sleeve is clamped in the accommodating space, and the reinforcing ribs are pressed against the limiting boss.

8. The self-sensing assembled ballastless track structure according to claim 1, characterized in that: It also includes a flexible pad, which is arranged between the bottom of the track plate and the top of the base plate. The flexible pad is provided with a plurality of second limiting holes arranged at a certain distance, each of the second limiting holes corresponds to a position of the first limiting hole, and the limiting boss passes through the second limiting hole.

9. The self-sensing assembled ballastless track structure according to claim 1, characterized in that: The track plate is pre-implanted with a radio frequency identification chip.

10. A construction method for a self-sensing assembled ballastless track structure, applied to the self-sensing assembled ballastless track structure according to any one of claims 1 to 9, characterized in that: The following steps are involved: A prefabricated track plate, wherein the track plate has a plurality of first limiting holes arranged at a certain distance, and a first groove is made between two adjacent first limiting holes; After the prefabricated track slab is transported to the construction site, connectors or gate-shaped bars are embedded or implanted on the lower foundation surface of the track slab on site, and the steel mesh of the self-compacting concrete layer is arranged at the same time; The track plate 1 is fixed and roughly laid to the corresponding position by a fixing tool, and the grating array temperature sensor optical cable is installed to the designated position. The designated position is that the grating array temperature sensor optical cable enters the first accommodation space from between the track plate and the bottom plate and extends into the first groove, and then comes out of the track plate and the bottom plate through the second accommodation space. The grating array temperature sensor optical cable is in the shape of a number of "X"s connected in sequence, and the track plate is finely adjusted; Install formwork around the bottom of the track slab to prevent leakage when pouring self-compacting concrete; Self-compacting concrete is poured from one of the limiting holes of the track plate. The concrete first fills the bottom of the track plate under the action of gravity to form a self-compacting concrete adjustment layer as the bottom plate. The concrete gradually rises and fills the first limiting hole to form a limiting boss. The other limiting hole of the track plate is used as an air outlet or observation hole. During grouting, the self-compacting concrete adjustment layer and the limiting boss are integrally poured and formed at one time. The smooth first groove should be roughened to ensure the stability of the combination of new and old concrete, and the concrete surface should be smoothed. After the self-compacting concrete layer and the concrete in the first groove reach a certain strength, the track plate template and fixing tooling should be removed; Secure the installed grating array temperature sensor optical cable and track plate, install the rails and fasteners on the track plate and retest.

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