Rail soundness calculation method and rail soundness calculation system

Abstract

To provide a rail soundness calculation method and a rail soundness calculation system capable of calculating rail soundness by a simple and efficient method.SOLUTION: A rail soundness calculation method comprises: a measurement step of measuring a high / low displacement waveform and an axle box acceleration waveform of a track; a waveform calculation step of calculating a floating sleeper waveform from the high / low displacement waveform; a section specification step of specifying a peak position exceeding a predetermined threshold in the high / low displacement waveform or the floating sleeper waveform, and specifying a section having a predetermined offset amount centered on the peak position; an amount calculation step of calculating a floating amount of a sleeper which is the maximum value of the floating sleeper waveform in the section and a rail irregularity amount calculated from the maximum value and a minimum value of the axle box acceleration waveform; and a rail soundness calculation step of calculating rail stress from the floating amount of the sleeper and the rail irregularity amount to calculate rail soundness.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rail soundness calculation method and a rail soundness calculation system for evaluating the soundness of a rail, and in particular to a method and a system for calculating rail soundness caused by irregularities on the rail head surface and floating sleepers. [Background technology]

[0002] Conventionally, for the purpose of maintaining and managing the tracks on which railway vehicles run, the location of rail damage has been estimated by understanding rail corrosion, which is a cause of rail damage, and preventing rail damage from occurring in the first place.

[0003] Various methods are known for preventing the occurrence of such rail damage. For example, a method for evaluating rail soundness is described in Patent Document 1.

[0004] The rail soundness assessment method described in Patent Document 1 is a rail soundness assessment method for assessing rail soundness associated with corrosion, and includes the steps of acquiring rail corrosion amount data associated with the rail position, estimating rail generated stress associated with the rail position, specifying rail fatigue strength based on the corrosion amount data, and calculating rail soundness at the rail position based on the rail generated stress and the rail fatigue strength.

[0005] According to this rail soundness evaluation method, rail corrosion amount data associated with the rail position is obtained to identify the rail fatigue strength, rail generated stress associated with the rail position is estimated, and the rail soundness at each rail position can be calculated based on the obtained rail generated stress and rail fatigue strength. Therefore, by utilizing not only the rail corrosion amount data but also indicators indicating the track condition and the estimation results, it is possible to efficiently quantitatively evaluate the rail soundness at any rail position on a commercial line. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2023-075806 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in order to apply the conventional rail soundness evaluation method to the maintenance of commercial tracks, there were the following problems in terms of data processing in the step of estimating rail stress as described above. First, in order to realize safer rail management, it is considered more appropriate to refer to a certain range of data, taking into account the actual occurrence characteristics of floating sleepers and rail head irregularities, the positions and occurrence amounts of which change continuously, rather than referring to data limited to a single point on a specific kilometer on a chart. However, a data processing method to realize this has not been established. Furthermore, it is known that water leakage, which promotes rail corrosion and rail head irregularities, occurs in tunnels, etc., and there was also a problem that data processing and extraction according to the positional relationship with ledger data of tunnels, etc., is required, rather than considering the entire range of track kilometers.

[0008] Furthermore, the rail soundness evaluation method described in Patent Document 1 uses data on elevation displacement and axle box acceleration, but these data are sampled at different intervals (25 cm for elevation displacement and 1 cm for axle box acceleration), making it difficult to simply compare these data. In other words, when the sampling intervals are different, a method is required to specify the values ​​of elevation displacement and axle box acceleration for any kilometer, and if there is a deviation in the peak positions of the elevation displacement and axle box acceleration data, the rail soundness is overestimated, making it impossible to properly evaluate it.

[0009] Therefore, the present invention has been made in consideration of the above problems, and has an object to provide a rail integrity calculation method and a rail integrity calculation system that can calculate rail integrity in a safer and more efficient manner. [Means for solving the problem]

[0010] The rail soundness calculation method of the present invention is characterized by comprising: a measuring step of measuring a track elevation displacement waveform and an axle box acceleration waveform; a waveform calculation step of calculating a floating sleeper waveform from the elevation displacement waveform; a section identification step of identifying a peak position in the elevation displacement waveform or the floating sleeper waveform which exceeds a predetermined threshold value and identifying a section having a predetermined offset amount centered on the peak position; an amount calculation step of calculating an amount of sleeper lift, which is the maximum value of the floating sleeper waveform in the section, and an amount of rail unevenness calculated from the maximum and minimum values ​​of the axle box acceleration waveform; and a rail soundness calculation step of calculating rail stress from the amount of sleeper lift and the amount of rail unevenness to calculate rail soundness.

[0011] In the rail soundness calculation method according to the present invention, it is preferable that the quantity calculation step multiplies the floating sleeper waveform or the axle box acceleration waveform by 0 to create a waveform with zero for the entire section, and then replaces data within the waveform with zero for the entire section with a maximum value of the floating sleeper waveform and a maximum and minimum value of the axle box acceleration waveform.

[0012] In the rail soundness calculation method according to the present invention, it is preferable that the rail soundness calculation step calculates the influence of each of the amount of uplift of the sleeper and the amount of rail unevenness.

[0013] In addition, in the rail soundness calculation method according to the present invention, it is preferable that the rail soundness calculation step refers to ledger waveform data obtained by converting ledger data of at least one of the tunnel type and the trackbed type into waveform data, and extracts the rail soundness of only the inside of the tunnel, the rail soundness of only the ballast track, or the rail soundness of only the ballast track inside the tunnel.

[0014] Furthermore, the rail soundness calculation system of the present invention is characterized in having measuring means for measuring a track elevation displacement waveform and an axle box acceleration waveform, waveform calculation means for calculating a floating sleeper waveform from the elevation displacement waveform, section identification means for identifying a peak position in the elevation displacement waveform or the floating sleeper waveform which exceeds a predetermined threshold value and for identifying a section having a predetermined offset amount centred on the peak position, amount calculation means for calculating an amount of sleeper floating calculated from the maximum value of the floating sleeper waveform in the section and an amount of rail unevenness calculated from the maximum and minimum values ​​of the axle box acceleration waveform, and rail soundness calculation means for calculating rail stress from the amount of sleeper floating and the amount of rail unevenness to calculate rail soundness.

[0015] The above summary of the invention does not list all of the necessary features of the present invention, and any subcombination of these features may also constitute an invention. Effect of the Invention

[0016] The rail soundness calculation method and rail soundness calculation system of the present invention include a section identification step of identifying a peak position in a height displacement waveform or a floating sleeper waveform that exceeds a predetermined threshold, and identifying a section having a predetermined offset amount centered on the peak position. Therefore, even if data with different sampling intervals are used, it is possible to automatically calculate the rail soundness using track inspection data, axle box acceleration data, and ledger data, and to automatically extract locations requiring caution regarding rail breakage while taking into account structures such as tunnels. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a flow diagram of a rail soundness calculation method according to an embodiment of the present invention. [Diagram 2] FIG. 4 is a diagram showing waveforms used in the rail soundness calculation method according to the embodiment of the present invention. [Diagram 3] FIG. 4 is a detailed flow diagram of a rail soundness calculation method according to an embodiment of the present invention. [Figure 4]FIG. 4 is a diagram showing a method of displaying the rail soundness in the rail soundness calculation method according to the embodiment. [Diagram 5] A graph showing the relationship between 5m chord height deviation and rail soundness. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and all of the combinations of features described in the embodiments are not necessarily essential to the solution of the invention.

[0019] FIG. 1 is a flow diagram of a rail soundness calculation method according to an embodiment of the present invention, FIG. 2 is a diagram showing waveforms used in the rail soundness calculation method according to an embodiment of the present invention, FIG. 3 is a detailed flow diagram of the rail soundness calculation method according to an embodiment of the present invention, FIG. 4 is a diagram showing a method of displaying rail soundness in the rail soundness calculation method according to the present embodiment, and FIG. 5 is a graph showing the relationship between 5-m chord elevation displacement and rail soundness.

[0020] As shown in FIG. 1, the rail soundness calculation method according to this embodiment includes a rail soundness calculation means that performs a measurement step (S101), a waveform calculation step (S102), a section identification step (S103), a quantity calculation step (S104), and a rail soundness calculation step (S105).

[0021] The measurement step (S101) uses measuring means installed on a track inspection vehicle or the like to measure track elevation displacement waveforms and axle box acceleration waveforms. The elevation displacement is measured and evaluated based on the relative displacement between three points spaced apart in the longitudinal direction. For example, a method known as the 5m chord slash method is preferably used. The 5m chord slash method involves placing a 5m chord against the rail and measuring the distance between the string and the rail at its center position. The axle box acceleration is preferably measured using an acceleration sensor installed on an axle box support device or the like of the bogie of the track inspection vehicle, and measuring acceleration data simultaneously with track displacement data.

[0022] The measurement data of the elevation displacement and the axle box acceleration can be obtained as waveform data as shown in Figures 2(a) and (b).

[0023] In the waveform calculation step (S102), a floating sleeper waveform as shown in Fig. 2(c) is calculated from the elevation displacement waveform measured in the measurement step (S101). A floating sleeper is a state in which a gap occurs between the bottom of the sleeper and the ballast surface, and the floating sleeper waveform is a plot of the fluctuation in the amount of floating of the sleeper along the kilometer. Note that various conventionally known calculation methods can be used to calculate the floating sleeper waveform from the elevation displacement waveform.

[0024] In the section identification step (S103), a peak position exceeding a predetermined threshold is identified in the elevation displacement waveform or the floating sleeper waveform, and a section having a predetermined offset amount centered on the peak position is identified. Specifically, for example, in the elevation displacement waveform of FIG. 2(a), a point (P 1 ) is then identified. In the axle box acceleration waveform (see Fig. 2(b)) and the floating sleeper waveform (see Fig. 2(c)), 1 Section R with a specified offset centered on the same kilometer distance as 1 are specified as the starting kilometer distance and the ending kilometer distance. In the case of the rail soundness calculation method according to the present embodiment, when the measurement is performed using the 5m chord arrow method in the measurement step (S101), it is preferable to set 3m before and after as the specified offset. The offset amount can be changed as appropriate depending on the measurement method in the measurement step (S101), etc.

[0025] Furthermore, in section R 2 In the case where the points on the height displacement waveform that are below the threshold are close to each other, a specified offset amount may be specified from each peak position, and the offset amounts from each peak position may be superimposed to form a staircase shape.

[0026] Then, the maximum and minimum values ​​in the specified section are obtained for the axle box acceleration waveform and the floating sleeper waveform. Specifically, as shown in Figure 2(b) and (c), 1 Maximum axle box acceleration A max and minimum value A min , and the maximum value of the floating sleeper waveform F max Request.

[0027] The amount calculation step (S104) is a step of calculating the maximum value F of the floating sleeper waveform in each section identified in the section identification step (S103). max The maximum value of the sleeper lift and axle box acceleration waveform A calculated from max and minimum value A min Specifically, as shown in FIG. 3, the elevation displacement waveform or the axle box acceleration waveform is multiplied by 0 to create a waveform with zero for the entire section. Next, the data within the section identified in the section identification step (S103) is multiplied by 0 to create a waveform with zero for the entire section. max , maximum axle box acceleration A max and minimum value A min By this replacement, the maximum value of the floating sleeper F obtained from the floating sleeper and axle box acceleration, which are CSV data calculated from the floating sleeper waveform and the axle box acceleration waveform, is obtained. max and maximum axle box acceleration A max , minimum value A min This processing allows calculations to be performed using only data from one of the kilometer-distance tables, even if the floating sleeper waveform and the axle box acceleration waveform refer to different kilometer-distance tables (tables for associating data numbers with kilometer-distances), thereby avoiding minute positional deviations and enabling calculations to be performed at the exact same kilometer-distance.

[0028] Then, using a conventionally known calculation method, the maximum axle box acceleration A max and minimum value A min The amount of unevenness on the rail head surface is calculated from the difference between the maximum value of the floating sleeper F max is set as the amount of sleeper lift.

[0029] In the rail soundness calculation process (S105), first, rail stress σ m Calculate the rail stress σ m is the amount of unevenness on the top surface z (mm), the amount of floating of the sleeper d (mm), and a, b, and c are coefficients, σ m = az + bd + c. Then, the calculated rail stress σ m From rail soundness f h Calculate the rail soundness f h is the fatigue limit of the rail, σ c (MPa), then f h =1-σ m / σ c It can be calculated as follows.

[0030] In addition, the rail soundness calculation step (S105) is h After obtaining the above, as shown in Fig. 2(e), the data of structures such as tunnels shown in Fig. 2(d) and ledger data such as trackbed type and joint data are converted into waveform data to extract the rail soundness of only the sections where structures are present. Specifically, the data of the tunnel section and the ballast track section on the ledger are replaced with 1 for the waveform of all sections created in the amount calculation step (S104) where the data is 0, and the rail soundness of only the ballast track in the tunnel can be extracted by multiplying the obtained waveform with the rail soundness waveform. Similarly, if a waveform is created from the ledger data where only the joints are set to 1 and the other sections are set to 0, it becomes possible to determine the presence or absence of joints in the section identified in the section identification step (S103), i.e., the target section for rail soundness calculation.

[0031] As mentioned above, the rail soundness f h can be obtained from the amount of sleeper lift and the amount of rail unevenness. Therefore, it would be preferable to calculate the degree of influence of sleeper lift and rail unevenness separately and display the locations where rail soundness has deteriorated by separating the degree of influence of rail unevenness and sleeper lift on rail soundness, as shown in Fig. 4.

[0032] This makes it possible to determine whether an area where rail soundness has deteriorated and is deemed to be at high risk is largely affected by rail unevenness or by the amount of sleeper lift, and makes it easy to select a maintenance method, such as grinding the rail top surface or maintaining the ballast track.

[0033] The rail soundness calculation method according to the present embodiment is preferably executed by a rail soundness calculation system. The rail soundness calculation system includes the above-mentioned measuring means for measuring a track elevation displacement waveform and an axle box acceleration waveform, a waveform calculation means for performing a waveform calculation step (S102) of calculating a floating sleeper waveform from the elevation displacement waveform, a section identification step (S103) of identifying a peak position in the elevation displacement waveform or the floating sleeper waveform that exceeds a predetermined threshold value and identifying a section having a predetermined offset amount centered on the peak position, an amount calculation means for performing an amount calculation step (S104) of calculating an amount of sleeper lift calculated from the maximum value of the floating sleeper waveform in the section and an amount of rail irregularity calculated from the maximum and minimum values ​​of the axle box acceleration waveform, and a rail soundness calculation step (S105) of calculating rail stress from the amount of sleeper lift and the amount of rail irregularity to calculate rail soundness.

[0034] The waveform calculation step (S102), section identification step (S103), quantity calculation step (S104), and rail soundness calculation step (S105) in the rail soundness calculation method according to this embodiment are preferably executed by processing means (not shown) provided on board the railway vehicle or on the ground. A processing device such as a computer is preferably used as the processing means. The processing device includes an arithmetic device such as a CPU (Central Processing Unit) that executes the processing program, a ROM (Read Only Memory) that stores the processing program, and a RAM (Random Access Memory) that temporarily stores data required for the CPU's processing. The processing device also preferably includes input devices such as a keyboard, a mouse, and a touch panel, output devices such as a CRT (Cathode-Ray-Tube) display, a liquid crystal display, and a printer, a communication interface, and the like.

[0035] Such a processing device is preferably a computer system constructed within a computer, and such computers may, for example, be personal computers, workstations, servers, tablet computers, etc., and various types of computers may be used as long as they operate in accordance with a program such as application software recorded in a storage device, and may be a single computer, or a group of computers in which multiple computers are connected so as to be able to communicate via a network or the like.

[0036] As described above, the rail soundness calculation method and rail soundness calculation system according to the present embodiment make it possible to calculate the rail soundness in a simpler and more efficient manner without underestimating the rail stress, even if there is a deviation in the peak positions of the axle box acceleration and floating sleeper waveforms.

[0037] Next, the rail soundness calculation method according to this embodiment was applied to data from a conventional railway line in operation to confirm its effectiveness. First, the outline of the target section where the rail soundness was evaluated is as follows: Track length: 59,500 km (single track, ballast track length in tunnel is 16.334 km), annual traffic tonnage: 1.8 to 3 million tons, main track structure: 50 kgN rail (standard length), ballast track, PC sleepers. Note that in calculating the rail soundness, rail stress σ m is calculated using a coefficient assuming a general express train running on the line, and the fatigue limit σ c was set at 180 MPa, assuming that there was 3 mm of corrosion at the bottom of the rail.

[0038] The calculation section was a range of 3 m before and after the peak position on the negative side of 5 m chord elevation displacement of -7 mm or less. To estimate the amount of rail unevenness, an axle box acceleration waveform bandpass filtered with a wavelength of 0.33 to 1.25 m was used, and to estimate the amount of sleeper lift, an elevation restoration waveform with a restoration band of 3 to 50 m was used.

[0039] As a result of using the rail soundness calculation method according to this embodiment, five locations (points A to E) where rail soundness had deteriorated were selected for on-site inspection, and a visual inspection was carried out, rail irregularity was measured by 1m stretching, and the amount of sleeper lift was measured by loosening the rail fastening devices. The results are shown in Table 1 below. In Table 1, the examples show the results calculated using the rail soundness calculation method according to this embodiment, and the comparative examples show the results of an on-site inspection.

[0040] [Table 1]

[0041] As is clear from Table 1, it was confirmed that the values ​​of the sleeper lift in the Example were roughly close to those in the Comparative Example. Although there was some error in the rail unevenness, it was confirmed that the values ​​of the Example and the Comparative Example were roughly close to each other. From these results, it was confirmed that the rail soundness calculation method according to this embodiment can appropriately evaluate defective areas.

[0042] Next, the rail soundness calculation method according to the present embodiment was compared with a rail management method in a tunnel using 5-m chord height displacement. FIG. 5 is a graph showing the relationship between the minimum value of 5-m chord height displacement in the calculation target section and rail soundness. As shown in FIG. 5, the 5-m chord height displacement and the rail soundness are highly correlated, and the risk of rail breakage can be properly grasped to some extent even with the rail management method in a tunnel using 5-m chord height displacement. However, for point B where a large rail unevenness was confirmed in the field survey, the 5-m chord height displacement was -8.9 mm, which is a relatively small amount of displacement, and it can be seen that the priority of treatment is evaluated relatively low in the conventional rail management method in a tunnel using 5-m chord height displacement.

[0043] From the above, the rail soundness calculation method according to this embodiment, which evaluates vehicle running surface irregularities with very short wavelength components (wavelength of 3 m or less), which cannot be evaluated by elevation displacement data alone, by estimating the amount of rail unevenness from the axle box acceleration, can more accurately evaluate the risk of rail breakage.

[0044] In addition, in the rail soundness calculation method and rail soundness calculation system according to the present embodiment described above, structure data and joint data are used as ledger data in the rail soundness calculation process, but the data is not limited to these ledger data and may be applied to the management and analysis of track irregularity data, such as the extraction of track irregularity data only for curved sections. It is clear from the claims that such modified or improved forms are also included in the technical scope of the present invention. [Explanation of symbols]

[0045] S101: Measurement process, S102: Waveform calculation process, S103: Section identification process, S104: Quantity calculation process, S105: Rail soundness calculation process.

Claims

1. a measuring step of measuring track elevation change waveforms and axle box acceleration waveforms; a waveform calculation step of calculating a floating sleeper waveform from the elevation displacement waveform; a section identification step of identifying a peak position that exceeds a predetermined threshold in the elevation displacement waveform or the floating sleeper waveform, and identifying a section having a predetermined offset amount centered on the peak position; a calculation step of calculating an amount of rail unevenness calculated from the amount of sleeper lift, which is the maximum value of the lifted sleeper waveform in the section, and the maximum and minimum values ​​of the axle box acceleration waveform; and a rail soundness calculating step of calculating rail stress from the amount of sleeper lift and the amount of rail unevenness to calculate rail soundness.

2. 2. The rail soundness calculation method according to claim 1, The rail soundness calculation method is characterized in that the quantity calculation step involves multiplying the floating sleeper waveform or the axle box acceleration waveform by 0 to create a waveform with zero for the entire section, and replacing the data within the waveform with zero for the entire section with the maximum value of the floating sleeper waveform and the maximum and minimum values ​​of the axle box acceleration waveform.

3. 2. The rail soundness calculation method according to claim 1, a rail soundness calculation step of calculating an influence of the amount of uplift of the sleeper and an influence of the amount of rail unevenness,

4. 2. The rail soundness calculation method according to claim 1, The rail soundness calculation step refers to ledger waveform data obtained by converting ledger data for at least one of the tunnel type and the trackbed type into waveform data, and extracts the rail soundness of only the tunnel, the rail soundness of only the ballast track, or the rail soundness of only the ballast track inside the tunnel.

5. A measuring means for measuring track elevation change waveforms and axle box acceleration waveforms; a waveform calculation means for calculating a floating sleeper waveform from the elevation displacement waveform; a section identification means for identifying a peak position exceeding a predetermined threshold in the elevation displacement waveform or the floating sleeper waveform, and for identifying a section having a predetermined offset amount centered on the peak position; an amount calculating means for calculating an amount of sleeper lift calculated from the maximum value of the lifted sleeper waveform in the section and an amount of rail unevenness calculated from the maximum and minimum values ​​of the axle box acceleration waveform; and rail soundness calculation means for calculating rail stress from the amount of sleeper lift and the amount of rail unevenness to calculate rail soundness.

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