Rail creep inspection method

Abstract

To provide a rail creep inspection method capable of efficiently measuring an amount of rail creep and of measuring the amount of rail creep with high accuracy.SOLUTION: The rail creep inspection method for a ballasted track includes measuring a separation distance between a sleeper-side target marked on a reference sleeper and a rail-side target marked on the rail.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a swelling inspection method for measuring the swelling amount of railway rails.

Background Art

[0002] It is known that railway rails can experience a phenomenon called "swelling" where they expand and contract in the longitudinal direction due to factors such as the passage of trains and changes in temperature. For example, rails expand under high temperatures and contract under low temperatures, in both cases causing a bias in the axial force inside the rail due to the progression of swelling, which can lead to buckling or breakage of the rail.

[0003] Therefore, the measurement of rail swelling amount is carried out as part of the track safety assessment. In particular, in long rail sections without joint structures, since the expansion and contraction of the rail cannot be alleviated by joints, the management of the axial force inside the rail becomes even more important.

[0004] Conventionally, in the measurement of the rail swelling amount, a pair of reference swelling piles are installed in advance on the ground on the left and right sides of the rail. Using the line connecting these swelling piles as a fixed point, the separation amount from the target marked on the rail is measured. The measurement of the separation amount is carried out by stretching a water thread between a pair of swelling piles by hand of an operator and using a ruler to measure the swelling amount, and there has been a demand for labor saving.

[0005] As a countermeasure against such problems, for example, as described in Patent Document 1, there is a method for measuring the rail swelling amount by measuring the rail swelling amount from a running image captured by imaging means attached to the front of a vehicle. In this method, from a pseudo-underfloor image obtained by performing projective transformation on an image captured at a predetermined interval in the forward or backward direction of travel, a pair of swelling piles provided on the left and right across the track and corresponding marks provided on the rail are extracted, and the swelling amount is measured from a reference line connecting the swelling piles with a horizontal line at a predetermined height and the marks.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] According to the method for measuring the amount of rail packing as described in Patent Document 1, the amount of rail packing can be measured from an image captured using imaging means from a moving vehicle, and the amount of packing can be efficiently measured.

[0008] However, in the invention described in Patent Document 1, it was difficult to ensure sufficient measurement accuracy because the distance from the packing pile to the rail was long and due to the influence of the shooting angle from the vehicle.

[0009] Therefore, the present invention has been made in view of the above matters, and an object thereof is to provide a packing inspection method capable of efficiently measuring the amount of rail packing and accurately measuring the amount of rail packing.

Means for Solving the Problems

[0010] This invention has been made to achieve the above object, and is characterized by the following.

[0011] The packing inspection method according to the present invention is a packing inspection method in a ballast track, and is characterized by measuring the separation distance between a sleeper-side target printed on a reference sleeper and a rail-side target printed on a rail.

[0012] In the packing inspection method according to the present invention, it is preferable that the reference sleeper is laid so as not to be movable in the rail length direction of the rail, and the rail is slidably supported in the rail length direction of the rail with respect to the reference sleeper.

[0013] In the method for inspecting creep according to the present invention, it is preferable that the separation distance between the sleeper-side target and the rail-side target is measured by a camera on the vehicle.

[0014] In the method for inspecting creep according to the present invention, it is preferable that the sleepers adjacent to the reference sleeper in the longitudinal direction of the rail length of the reference sleeper have the side surface on the reference sleeper side exposed from the ballast.

[0015] The above summary of the invention does not list all the features necessary for the present invention, and sub-combinations of these feature groups can also be inventions.

Effect of the Invention

[0016] According to the present invention, the sleeper-side target that becomes a fixed point and the rail-side target printed on the rail can be arranged close to each other, and the creep amount can be measured accurately. Further, according to the present invention, since the creep amount can be measured by a camera on the running vehicle, the creep amount can be measured efficiently.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0018] Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the invention according to each claim, and not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0019] [First Embodiment] FIG. 1 is a diagram showing a track structure used for the bulge inspection method according to the first embodiment of the present invention, (a) is a top view, (b) is a side view, FIG. 2 is a diagram showing a rail fastening device, (a) is a top view, (b) is a cross-sectional view of FIG. 2(a), and FIG. 7 is a cross-sectional view showing a conventional rail fastening device. In this specification, the rail length direction and the rail width direction refer to the directions of the arrows shown in FIG. 1(a).

[0020] The bulge inspection method according to the present embodiment is performed using a track structure A having a fixed sleeper structure 10 as shown in FIG.

[0021] The track structure A is a ballast track in which a pair of rails 1 are installed on the ballast laid along the traveling direction of the vehicle via sleepers 3 and a fixed sleeper structure 10.

[0022] The fixed sleeper structure 10 is arranged at a location where the measurement of the bulge amount is carried out. As an example, it is arranged at about 200 m intervals along the rail 1. Further, as an example, about 400 sleepers 3 are arranged at predetermined intervals along the rail 1 between two fixed sleeper structures 10 arranged at about 200 m intervals.

[0023] As shown in FIGS. 1(a) and 1(b), the fixed sleeper structure 10 includes at least two reference sleepers 11 and at least two connecting parts 13 that connect these reference sleepers 11 to each other. Further, a rail fastening device 50 for supporting the rail 1 is attached to the connecting part 13. In the following description, a configuration in which two reference sleepers 11 are connected by a pair of connecting parts 13 will be described as an example. However, the number of reference sleepers 11 and connecting parts 13 is not limited to this, and can be arbitrarily set according to the environment where the fixed sleeper structure 10 is installed.

[0024] As shown in FIG. 1(a), as an example, the reference sleeper 11 is formed as a square prism and is a member made of wood, concrete, or the like. The reference sleeper 11 is arranged to extend in the rail width direction, and the two reference sleepers 11 are arranged at a predetermined interval in the rail length direction. Further, on the upper surface of at least one of the two reference sleepers 11, a sleeper-side target 12 is marked at a position that is either outside or inside the pair of rails 1.

[0025] In the present embodiment, the description has been made assuming that the sleeper-side target 12 is marked on the upper surface of the reference sleeper 11. However, the position of the sleeper-side target 12 is not limited to this, and it may be the upper surface of the type plate 51 described later.

[0026] On the rail 1, a rail-side target 2 is marked at a position corresponding to the sleeper-side target 12. The rail-side target 2 is preferably marked on the upper surface of the rail bottom 1a shown in FIG. 2(b) at a position that overlaps the sleeper-side target 12 in the rail length direction. In this specification, a state in which there is no creep in the rail 1 and the rail-side target 2 and the sleeper-side target 12 are at positions that overlap in the rail length direction is defined as the reference state.

[0027] The connecting part 13 is, as an example, a member formed in a quadrangular prism shape and made of materials such as wood or concrete. The connecting part 13 is arranged to extend along the rail length direction, and a pair of connecting parts 13 are arranged at intervals in the rail width direction. At this time, it is preferable that the pair of connecting parts 13 are arranged at positions corresponding to the pair of rails 1. Further, the longitudinal end faces of the connecting part 13 are firmly connected to the reference sleeper 11 respectively. The connecting part 13 may be a member separate from the reference sleeper 11 and connected to the reference sleeper 11 using a connecting member such as a bolt and nut, or may be formed integrally with the reference sleeper 11.

[0028] As described above, the two reference sleepers 11 and the pair of connecting parts 13 arranged as such form a space 14 between the pair of rails 1 as shown in Fig. 1(a). Ballast can be laid in the space 14, and the resistance against the force in the rail length direction of the fixed sleeper structure 10 (hereinafter referred to as the longitudinal track resistance) can be increased.

[0029] As shown in Figs. 2(a) and (b), the rail fastening device 50 supports the rail 1 by the type plate 51 and the fitting 52.

[0030] The type plate 51 is an iron plate formed in a substantially rectangular shape and provided with a pair of shoulder portions 51a on the upper surface. The pair of shoulder portions 51a are formed in a convex shape at positions corresponding to the width dimension of the rail bottom portion 1a of the rail 1. Further, between the pair of shoulder portions 51a, the rail 1 is installed so as to directly contact the upper surface of the type plate 51. According to the shoulder portion 51a formed in this way, it is possible to resist the lateral pressure by the rail 1 and support the rail 1 so as not to move in the rail width direction. Further, the type plate 51 is fixed by the anchor bolt 54 with the rubber pad 53 inserted between it and the connecting part 13.

[0031] As shown in Fig. 2(b), the fitting 52 has legs 52a and 52b and is an iron member formed in a substantially U shape. The fitting 52 is attached to the shoulder portion 51a by a fastening member such as a bolt and nut. At this time, the end face of the leg 52a faces the upper surface of the rail bottom 1a. A clearance 55 of a predetermined size is formed between the end face of the leg 52a and the upper surface of the rail bottom 1a. The fitting 52 attached in this way supports the rail 1 so as not to move in the vertical direction and can prevent the rail 1 from tilting inward or outward in the gauge (hereinafter referred to as rail skew).

[0032] The rail fastening device 50 having such a structure supports the rail 1 with a clearance 55 formed between the rail 1 and the fitting 52 without interposing a member that increases the frictional force such as a rubber pad between the rail 1 and the type plate 51. Therefore, even when creep occurs in the rail 1, the rail 1 can slide in the rail length direction with respect to the rail fastening device 50.

[0033] As shown in Figs. 1(a) and (b), the sleeper 3 is, as an example, a member formed in a square prism shape and made of wood or concrete. The sleeper 3 is arranged to extend in the rail width direction and is arranged at a predetermined interval in the rail length direction from the reference sleeper 11 and the other sleepers 3. Further, as an example, a conventional rail fastening device 60 is attached to the sleeper 3, and the conventional rail fastening device 60 supports the rail 1 so as not to move relative to the sleeper 3.

[0034] As an example, as shown in Fig. 7, the conventional rail fastening device 60 supports the rail 1 by a plurality of main springs 61 and a rubber pad 62.

[0035] The main springs 61 are respectively arranged inside and outside the rail width direction of the rail 1 and are fixed to the sleeper 3 by fastening bolts 63. Further, the main spring 61 presses the upper surface of the rail bottom 1a by tightening the fastening bolt 63 and supports the rail 1.

[0036] The rubber pad 62 is disposed between the rail 1 and the sleeper 3, and the frictional force between the rail 1 and the sleeper 3 can be increased by tightening the fastening bolt 63.

[0037] The conventional rail fastening device 60 having such a structure can prevent the movement of the rail 1 in the rail length direction with respect to the sleeper 3 due to the frictional force between the rail 1 and the sleeper 3. Therefore, when creep occurs in the rail 1, the sleeper 3 moves integrally with the rail 1.

[0038] As shown in Fig. 1(b), a space 4 where no ballast is laid is formed between the reference sleeper 11 and the sleeper 3 adjacent in the rail length direction, and the side surface of the sleeper 3 facing the side surface of the reference sleeper 11 is arranged so as to be exposed from the ballast. When creep occurs in the rail 1 and the sleeper 3 moves integrally with the rail 1 toward the reference sleeper 11, the sleeper 3 moves within the range of the space 4. Therefore, even when creep occurs in the rail 1, no load generated due to the movement of the adjacent sleeper 3 is applied to the fixed sleeper structure 10 via the ballast.

[0039] Thus, the fixed sleeper structure 10 according to the present invention is a structure that exhibits sufficient longitudinal track resistance by the ballast laid in the space 14 and does not receive the load caused by the movement of the adjacent sleeper 3. Further, the rail 1 is supported by the rail fastening device 50 so as to be slidable in the rail length direction. Therefore, even when creep occurs in the rail 1 or when the rail 1 receives an impact or the like during train running, the fixed sleeper structure 10 does not move.

[0040] Next, a method for measuring the creep amount using the track structure A as described above will be described.

[0041] Fig. 3 is a diagram showing a state of measuring the creep amount by the creep inspection method according to the present embodiment, (a) is a side view of the track structure as viewed from the side, and (b) is a reference diagram showing an example of the underfloor image shown in Fig. 3(a).

[0042] As shown in FIG. 3(b), when creep occurs in the rail 1, the rail-side target 2 marked on the rail 1 moves following the creep of the rail 1. At this time, since the fixed tie structure 10 does not move, the tie-side target 12 attached to the reference tie 11 can be treated as a fixed point. Also, in the reference state where no creep occurs in the rail 1, the rail-side target 2 and the tie-side target 12 are marked at positions that overlap in the rail length direction. Therefore, the amount of creep of the rail 1 is the separation distance between the tie-side target 12 and the rail-side target 2 in the rail length direction.

[0043] Also, as shown in FIGS. 3(a) and (b), the amount of creep of the rail 1 can be measured in a state viewed from directly above. Therefore, by installing a photographing device such as a camera at the bottom of the vehicle and analyzing the image obtained during the running of the vehicle, the amount of creep of the rail 1 can be measured.

[0044] Thus, according to the creep inspection method according to the present embodiment, since the tie-side target 12 serving as a fixed point and the rail-side target 2 that moves due to creep are arranged close to each other, the amount of creep can be measured accurately.

[0045] Also, the tie-side target 12 is attached to the reference tie 11 and is not installed separately and independently on the ground or ballast around the tie. Therefore, when performing work such as tamping the ballast around the reference tie 11 or the tie 3, there is no obstacle installed.

[0046] Also, since the tie-side target 12 and the rail-side target 2 can be photographed from directly above to measure the amount of creep, correction due to the photographing angle is not required, and the amount of creep can be measured accurately.

[0047] [Second Embodiment] The above-described creep inspection method according to the first embodiment is a creep inspection method that uses a track structure A capable of increasing the longitudinal resistance of the roadbed of the fixed sleeper structure 10 by laying ballast in the space 14 formed in the fixed sleeper structure 10, and treats the sleeper side target 12 marked on the reference sleeper 11 as a fixed point. Next, the creep inspection method according to the second embodiment to be described is a creep inspection method performed using a track structure having a form different from that of the first embodiment. Note that members that are the same as or similar to those in the above-described first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0048] FIG. 4 is a diagram showing a track structure used in the creep inspection method according to the second embodiment of the present invention, where (a) is a plan view and (b) is a side view.

[0049] As shown in FIG. 4, the creep inspection method according to the present embodiment is performed using a track structure B having a fixed sleeper structure 20.

[0050] The fixed sleeper structure 20 is arranged at a location where the measurement of the creep amount is carried out, in the same manner as the fixed sleeper structure 10 according to the first embodiment. As an example, it is arranged at intervals of about 200 m along the rail 1. Further, between two fixed sleeper structures 20 arranged at intervals of about 200 m, as an example, about 400 sleepers 3 are arranged along the rail 1 at predetermined intervals.

[0051] As shown in FIGS. 4(a) and 4(b), the fixed sleeper structure 20 includes a reference sleeper 21. A rail fastening device 50 that slidably supports the rail 1 in the rail length direction is attached to the reference sleeper 21.

[0052] As shown in FIG. 4(a), the reference sleeper 21 is, as an example, formed as a square prism and is a member made of wood, concrete, or the like. Further, the reference sleeper 21 is formed to be longer than the sleeper 3 and is arranged so as to extend in the rail width direction. On the upper surface of the reference sleeper 21, sleeper side targets 22 are marked at positions that are outside or inside a pair of rails 1.

[0053] Thus, according to the reference sleeper 21 formed to be longer than the sleeper 3, the load applied to the reference sleeper 21 can be widely dispersed and transmitted to the ballast, so that the longitudinal track resistance can be increased.

[0054] Between the reference sleeper 21 and the sleeper 3 adjacent in the rail length direction, as shown in Fig. 4(b), a space 4 where no ballast is laid is formed, and the side surface of the sleeper 3 facing the side surface of the reference sleeper 21 is arranged to be exposed from the ballast. For this reason, similar to the fixed sleeper structure 10 according to the first embodiment, even when creep occurs in the rail 1, no load generated due to the movement of the adjacent sleeper 3 is applied to the fixed sleeper structure 20 via the ballast.

[0055] Thus, the fixed sleeper structure 20 according to the present embodiment is a structure that exhibits sufficient longitudinal track resistance by the reference sleeper 21 formed in a long shape and does not receive the load caused by the movement of the adjacent sleeper 3. Further, the rail 1 is supported by the rail fastening device 50 so as to be slidable in the rail length direction. For this reason, even when creep occurs in the rail 1 or when the rail 1 receives an impact or the like during train running, the fixed sleeper structure 20 does not move.

[0056] When measuring the creep amount using such a track structure B, similar to the creep inspection method according to the first embodiment, the sleeper side target 22 attached to the reference sleeper 21 is treated as a fixed point, and the distance from the rail side target 2 to the sleeper side target 22 can be obtained by analyzing an image obtained by a photographing device attached to the bottom of the vehicle.

[0057] In the present embodiment, the description has been made assuming that the sleeper side target 22 is printed on the upper surface of the reference sleeper 21, but the position of the sleeper side target 22 is not limited to this and may be the upper surface of the nameplate 51.

[0058] [Third Embodiment] The above-described jacking inspection method according to the second embodiment was described using the track structure B that can increase the longitudinal track resistance of the fixed sleeper structure 20 by forming the reference sleeper 21 in a long shape, and treating the sleeper-side target 22 marked on the reference sleeper 21 as a fixed point. Next, the jacking inspection method according to the third embodiment to be described is a jacking inspection method performed using a track structure having a form different from those of the first and second embodiments. For members that are the same as or similar to those in the above-described first and second embodiments, the same reference numerals are given and detailed descriptions thereof are omitted.

[0059] FIG. 5 is a diagram showing a track structure used in the jacking inspection method according to the third embodiment of the present invention, where (a) is a plan view and (b) is a side view.

[0060] As shown in FIG. 5, the jacking inspection method according to the present embodiment is performed using a track structure C having a fixed sleeper structure 30.

[0061] The fixed sleeper structure 30 is arranged at a location where the measurement of the jacking amount is carried out, similar to the fixed sleeper structure 10 according to the first embodiment. As an example, it is arranged at intervals of about 200 m along the rail 1. Also, between two fixed sleeper structures 30 arranged at intervals of about 200 m, as an example, about 400 sleepers 3 are arranged at predetermined intervals along the rail 1.

[0062] As shown in FIGS. 5(a) and 5(b), the fixed sleeper structure 30 includes a reference sleeper 31. A rail fastening device 50 that slidably supports the rail 1 in the rail length direction is attached to the reference sleeper 31.

[0063] As shown in Fig. 5(a), the reference sleeper 31 is, for example, a member formed in a square prism shape and made of materials such as wood or concrete. The reference sleeper 31 is arranged to extend in the rail width direction and is provided with movement prevention plates 33 at both ends in the rail width direction. Further, on the upper surface of the reference sleeper 31, sleeper side targets 32 are marked at positions that are outside or inside of the pair of rails 1.

[0064] The movement prevention plate 33 is formed in a substantially T shape as viewed in Fig. 5(a) and is, for example, a member made of materials such as iron or concrete. The movement prevention plate 33 has a flat plate-shaped arm portion 33a that extends toward the outside in the rail width direction. The movement prevention plate 33 is attached to both ends of the reference sleeper 31 such that the flat surface portion of the arm portion 33a faces in the rail length direction. The movement prevention plate 33 may be a member separate from the reference sleeper 31 and attached by a fastening member such as a bolt, or may be integrally formed with the reference sleeper 31.

[0065] According to the reference sleeper 31 provided with such a movement prevention plate 33, the load applied to the reference sleeper 31 can be widely dispersed and transmitted to the ballast, so that the longitudinal resistance of the roadbed can be increased.

[0066] As shown in Fig. 5(b), a space 4 where no ballast is laid is formed between the reference sleeper 31 and the sleeper 3 adjacent in the rail length direction, and the side surfaces of the sleeper 3 facing the side surface of the reference sleeper 31 are arranged to be exposed from the ballast. Therefore, similar to the fixed sleeper structure 10 according to the first embodiment, even when creep occurs in the rail 1, in the fixed sleeper structure 30, the load generated due to the movement of the adjacent sleeper 3 is not applied via the ballast.

[0067] Thus, the anti-displacement tie structure 30 according to this embodiment exhibits sufficient longitudinal track resistance by the reference tie 31 having substantially T-shaped anti-displacement plates 33 at both ends, and moreover, it is a structure that does not receive the load caused by the movement of the adjacent tie 3. Further, the rail 1 is supported by a rail fastening device 50 so as to be slidable in the rail length direction. For this reason, even when creep occurs in the rail 1 or when the rail 1 is subjected to an impact or the like during train running, the anti-displacement tie structure 30 does not move.

[0068] When measuring the creep amount using such a track structure C, in the same manner as the creep inspection method according to the first embodiment, the tie-side target 32 attached to the reference tie 31 is treated as a fixed point, and the distance from the rail-side target 2 to the tie-side target 32 can be obtained by analyzing the image obtained by the imaging device attached to the bottom of the vehicle.

[0069] In this embodiment, the tie-side target 32 has been described as being marked on the upper surface of the reference tie 31, but the position of the tie-side target 32 is not limited to this and may be the upper surface of the nameplate 51.

[0070] [Fourth Embodiment] The creep inspection method according to the third embodiment described above has been described for a creep inspection method that uses a track structure C capable of increasing the longitudinal track resistance of the anti-displacement tie structure 30 by attaching the anti-displacement plate 33 to the reference tie 31 and treats the tie-side target 32 marked on the reference tie 31 as a fixed point. Next, the creep inspection method according to the fourth embodiment to be described is a creep inspection method performed using a track structure having a form different from the first to third embodiments. Note that members that are the same as or similar to those in the first to third embodiments described above are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0071] FIG. 6 is a diagram showing a track structure used in the creep inspection method according to the fourth embodiment of the present invention, where (a) is a plan view and (b) is a side view.

[0072] The jacking inspection method according to this embodiment is performed using an orbital structure D having a fixed sleeper structure 40, as shown in FIG. 6.

[0073] The fixed sleeper structure 40 is arranged at a location where the jacking amount is measured, similarly to the fixed sleeper structure 10 according to the first embodiment. As an example, it is arranged at approximately 200 m intervals along the rail 1. Also, between two fixed sleeper structures 40 arranged at approximately 200 m intervals, as an example, approximately 400 sleepers 3 are arranged at predetermined intervals along the rail 1.

[0074] The fixed sleeper structure 40 includes a reference sleeper 41, as shown in FIGS. 6(a) and 6(b). A rail fastening device 50 that slidably supports the rail 1 in the rail length direction is attached to the reference sleeper 41.

[0075] The reference sleeper 41 is, as an example, formed in a square prism shape and is a member made of wood, concrete, or the like. Also, the reference sleeper 41 is arranged so as to extend in the rail width direction and is fixed to the ballast by passing through the pile 43. Sleeper-side targets 42 are marked at positions on the upper surface of the reference sleeper 41 that are outside or inside the pair of rails 1.

[0076] The pile 43 is, as an example, formed of wood, steel, concrete, or the like. The pile 43 only needs to be able to increase the frictional force with the ballast in contact with its outer peripheral surface, and the length and number thereof can be arbitrarily set according to the environment where the reference sleeper 41 is installed.

[0077] The reference sleeper 41 fixed by such a pile 43 can transmit the load applied to the reference sleeper 41 to the ballast in contact with the outer peripheral surface of the pile 43, so that the longitudinal track resistance can be increased.

[0078] Between the reference sleeper 41 and the adjacent sleeper 3 in the rail length direction, as shown in Fig. 6(b), a space 4 where no ballast is laid is formed, and the side surface of the sleeper 3 facing the side surface of the reference sleeper 41 is arranged to be exposed from the ballast. For this reason, similar to the fixed sleeper structure 10 according to the first embodiment, even when creep occurs in the rail 1, the fixed sleeper structure 40 is not subjected to the load generated due to the movement of the adjacent sleeper 3 via the ballast.

[0079] Thus, the fixed sleeper structure 40 according to this embodiment exhibits sufficient longitudinal track resistance by the reference sleeper 41 fixed using the pile 43, and moreover, is a structure that does not receive the load caused by the movement of the adjacent sleeper 3. Further, the rail 1 is supported by the rail fastening device 50 slidably in the rail length direction. For this reason, even when creep occurs in the rail 1 or when the rail 1 receives an impact or the like during train running, the fixed sleeper structure 40 does not move.

[0080] When measuring the creep amount using such a track structure D, similar to the creep inspection method according to the first embodiment, the sleeper side target 42 attached to the reference sleeper 41 is treated as a fixed point, and the distance from the rail side target 2 to the sleeper side target 42 can be obtained by analyzing the image obtained by the imaging device attached to the bottom of the vehicle.

[0081] In this embodiment, the sleeper side target 42 has been described as being marked on the upper surface of the reference sleeper 41, but the position of the sleeper side target 42 is not limited to this and may be the upper surface of the nameplate 51.

[0082] Note that the present invention is not limited to the above-described embodiments, and its configuration may be changed, added, or deleted without departing from the gist of the present invention. For example, the rail-side target 2 and the bolster-side targets 12, 22, 32, 42 may be separate members attached to the rail 1 or the reference bolsters 11, 21, 31, 42, or may be lines drawn directly on the rail 1 or the reference bolsters 11, 21, 31, 42, or depressions. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

Explanation of Signs

[0083] A, B, C, D track structures, 1 rail, 1a rail bottom, 2 rail-side target, 3 bolster, 4 space, 10, 20, 30, 40 fixed bolster structures, 11, 21, 31, 41 reference bolsters, 12, 22, 32, 42 bolster-side targets, 13 connection part, 14 space, 33 anti-movement plate, 33a arm part, 43 pile, 50 rail fastening device, 51 type plate, 51a shoulder part, 52 fitting, 52a, 52b leg parts, 53 rubber pad, anchor bolt, 55 clearance, 60 conventional rail fastening device, 61 main spring, 62 rubber pad, 63 fastening bolt.

Claims

1. A method for inspecting ballast track compaction, comprising: measuring the separation distance between a sleeper-side target marked on a reference sleeper and a rail-side target marked on a rail.

2. In the method for inspecting ballast track compaction according to Claim 1, the reference sleeper is laid immovably in the rail length direction of the rail, and the rail is supported slidably in the rail length direction of the rail with respect to the reference sleeper.

3. In the method for inspecting ballast track compaction according to Claim 1, the separation distance between the sleeper-side target and the rail-side target is measured by a camera on the vehicle.

4. In the method for inspecting ballast track compaction according to Claim 1, the sleepers adjacent to the reference sleeper in the front and rear in the rail length direction of the rail have the side surface on the reference sleeper side exposed from the ballast.

Images