JP6709680B2 - Artificial ballast and ballast and its improvement method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an artificial ballast that is mixed with a ballast ballast to form a ballast, a ballast that supports a support by a ballast layer, and an improved method thereof.

The conventional artificial ballast is a cement concrete structure in which at least one surface of the outer wall surface is a flat surface and the flat surface has fine irregularities (for example, refer to Patent Document 1). Such a conventional artificial ballast forms a roadbed by mixing with crushed stone, and when compacted by compacting or rolling the roadbed, the ridge of the crushed stone and a flat surface having irregularities are formed. Correlation suppresses subsidence of the bed.

JP 2009-052320

Various types of ballast layer deterioration prevention measures have been developed, including elastic sleepers, but the effects are rarely apparent. In addition, at present, none of the shock load reduction effects on trains have been confirmed. In a ballast track of a railway, crushed stones are worn and deteriorated by the impact load when passing through the train, and then the crushed stones rotate and move, causing irregularities on the track surface. In order to maintain this, the railway operator is performing repair work by manpower tactics at night, but at present there is no countermeasure work that has been confirmed to have a definitive effect.

An object of the present invention is to provide an artificial ballast and a ballast that can reduce an impact load when passing a train, and an improved construction method thereof.

The present invention solves the above-mentioned problems by the solution means described below.
It should be noted that although description is given with reference numerals corresponding to the embodiment of the present invention, the present invention is not limited to this embodiment.
1 to 3 and 8 to 10, the invention of claim 1 is an artificial ballast that is mixed with a ballast ballast (10) to form a ballast (9), and has a plurality of smooth flat surfaces. It is a polyhedral shape having parts (11c; 11d, 11e) on the entire surface , and is a block body made of an aluminum alloy, a thermosetting resin, or a geopolymer concrete having substantially the same size as the ballast ballast, and the ballast ballast. With an artificial ballast (11), which absorbs an impact load generated when a train passes by reciprocating the ballast ballast while sliding on the flat portion while the corner portion of the ball is in contact with the flat portion. is there.

The invention of claim 2 is the artificial ballast according to claim 1, characterized in that, as shown in FIG. 3, it is a hexahedral shape having six quadrangular smooth plane portions (11c). ..

According to the invention of claim 3, in the artificial ballast according to claim 1, as shown in FIG. 8, two substantially parallel triangular bottom surfaces (11d) and three quadrangular smooth side surfaces (11e). An artificial ballast having a triangular prism shape having and.

The invention of claim 4 is a track bed, as shown in FIGS. 1, 2, 9 and 10, in which a support (7) is supported by a ballast layer, and the invention is any one of claims 1 to 3 . A roadbed (9) comprising a mixed layer (12) in which the artificial ballast (11) according to item 1 and the ballast ballast (10) are mixed.

A fifth aspect of the present invention is the trackbed according to the fourth aspect , wherein the mixed layer has a depth (D) within a range of 100 to 200 mm from a lower surface of the sleeper when the support is a sleeper. It is a dojo characterized by being present.

The invention of claim 6 is the trackbed according to claim 4 or claim 5 , wherein in the mixed layer, when the support is a sleeper, the mixing amount of the artificial ballast per one sleeper is The dojo is characterized by 80 to 120 pieces.

According to a seventh aspect of the present invention, in the roadbed according to any one of the fourth to sixth aspects, as shown in FIGS. 9 and 10, the support cushions a shock acting on the ballast layer. The roadbed is characterized by being an elastic sleeper having a cushioning member (7a) on its bottom surface.

The invention of claim 8, as shown in FIGS. 4 to 7, an improvement method of the track bed to improve track bed (9) supporting the support (7) by the ballast layer, claims 1 to 3 A mixed layer forming step (#120; #140) of forming a mixed layer (12) in which the artificial ballast (11) according to any one of the above items and the ballast ballast (10) are mixed. It is an improved construction method (#100) of the roadbed.

According to a ninth aspect of the present invention, in the improved roadbed construction method according to the eighth aspect , the mixed layer forming step has a depth (D) of 100 to 100 from a lower surface of the sleeper when the support is a sleeper. It is an improved roadbed construction method including a step of forming the mixed layer within a range of up to 200 mm.

According to a tenth aspect of the present invention, in the improved road bed construction method according to the eighth or ninth aspect , in the mixed layer forming step, when the support is a sleeper, the artificial material per one sleeper is used. An improved roadbed construction method, which comprises the step of forming the mixed layer so that the mixed amount of ballast is 80 to 120.

According to the present invention, it is possible to reduce the impact load when passing a train.

It is a front view which shows schematically the track provided with the artificial ballast which concerns on 1st Embodiment of this invention. It is a side view which shows schematically the track provided with the artificial ballast which concerns on 1st Embodiment of this invention. It is an outline view showing the artificial ballast concerning a 1st embodiment of this invention, (A) is a perspective view, (B) is a top view, (C) is a front view, and (D). ) Is a side view and (E) is a bottom view. It is a process drawing at the time of renewal of a roadbed in the improvement method of a roadbed concerning a 1st embodiment of this invention. It is a schematic diagram for demonstrating the operation|work at the time of renewal of the roadbed of the roadbed improvement construction method which concerns on 1st Embodiment of this invention, (A) is a schematic diagram which shows an excavation process, (B) is a mixed layer formation process. And (C) is a schematic diagram showing a roadbed arrangement process. It is a process drawing at the time of new installation of the roadbed in the improved roadbed construction method according to the first embodiment of the present invention. It is a schematic diagram for demonstrating the work at the time of new installation of the roadbed of the improved roadbed construction method which concerns on 1st Embodiment of this invention, (A) is a schematic diagram which shows a mixed layer forming process, (B) is a railroad track. It is a schematic diagram which shows a laying process, (C) is a schematic diagram which shows a roadbed rearrangement process. It is an external view which shows schematically the artificial ballast which concerns on 2nd Embodiment of this invention, (A) is a perspective view, (B) is a top view, (C) is a front view, (D). ) Is a side view and (E) is a bottom view. It is a front view which shows schematically the track provided with the artificial ballast which concerns on 3rd Embodiment of this invention. It is a side view which shows schematically the track provided with the artificial ballast which concerns on 3rd Embodiment of this invention. It is a perspective view which shows roughly a weight drop impact loading experiment. It is a top view which shows roughly a weight drop impact loading experiment. It is sectional drawing which shows the state cut|disconnected by the XIII-XIII line of FIG. 13 schematically. It is a longitudinal cross-sectional view schematically showing a weight drop impact loading experiment. It is a graph which shows the acceleration spectrum which acts on a ballast layer by a weight drop impact loading experiment. It is a graph which shows the time change of the amount of subsidence by a weight drop impact loading experiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
The train 1 shown in FIG. 1 is a moving body configured for the purpose of operating on the track 5. The train 1 is a passenger train for transporting passengers, a freight train for freight transportation, or a mixed train that operates by combining passenger trains and freight trains. The train 1 is composed of one car or a plurality of cars 1A. The vehicle 1A is a railway vehicle that travels on the track 5. The vehicle 1A is a train, railcar, locomotive, passenger car, or freight car. The vehicle 1A includes a vehicle body 2, wheels 3, and the like.

The vehicle body 2 is a structure for loading and transporting passengers or cargo. The wheel 3 is a member that makes rotational contact with the pair of left and right rails 6, respectively. As shown in FIG. 1, the wheel 3 includes a tread surface that is in contact with the top surface of the rail head and receives frictional resistance, and a flange surface that is continuously formed on the outer peripheral portion of the wheel 3 to prevent wheel loss. Is equipped with.

The roadbed 4 is a base that supports the track 5, and is a structure that supports the load when the train 1 passes on the track 5. The roadbed 4 is composed of, for example, a crushed stone roadbed (soilbed) that is sufficiently compacted using high quality natural soil that is difficult to freeze, or crusher run, an upper roadbed made of an asphalt mixture, and a lower roadbed made of crushed stone. Asphalt roadbed (reinforced roadbed), or concrete roadbed composed of reinforced concrete slab and crushed stone.

The track 5 is a passage (track) through which the train 1 travels. The track 5 includes a rail 6, a sleeper 7, a rail fastening device 8, a track 9, and the like. The track 5 shown in FIGS. 1 and 2 is a general track structure laid on a railroad track, and is a ballast track mainly composed of rails 6, sleepers 7, ballast ballasts 10 and artificial ballasts 11.

The rail 6 is a member that supports and guides the wheels 3 of the train 1 to run the train 1. As shown in FIG. 1, the rail 6 has a rail head portion that comes into contact with the wheels 3 of the train 1, a rail bottom portion (flange portion) that is attached to the sleeper 7, and a rail belly portion that connects the rail head portion and the rail bottom portion ( Web department) etc.

The sleeper 7 shown in FIGS. 1 and 2 is a support (support) for supporting the rail 6. The sleepers 7 are installed between the rails 6 and 9 in order to accurately maintain the distance (gauge) between the left and right rails 6 and to distribute the train load transmitted from the rails 6 to the roadbed 9. There is. The sleeper 7 is a track constituent member that constitutes a part of the track 5. The sleepers 7 shown in FIG. 1 and FIG. 2 are horizontal sleepers arranged side by side at right angles to the rails 6 (normal sleepers used in a general section). The sleeper 7 is, for example, a prestressed concrete sleeper (PC sleeper) prestressed by a steel material (Prestressing Steel (PC)) used as a tension material. As shown in FIG. 2, the sleepers 7 are arranged at predetermined intervals in the length direction of the rail 6 and discretely support the rail 6. The sleeper 7 has a length of 2100 mm, a width of 200 mm and a thickness of 140 mm for the conventional line, and a length of 2600 mm, a width of 240 mm or 350 mm and a thickness of 150 mm for the Shinkansen. Is.

The rail fastening device 8 shown in FIGS. 1 and 2 is a device for fastening the rail 6 to the sleeper 7. The rail fastening device 8 is a track pad that is inserted between the rail 6 and the sleeper 7 to reduce the impact generated when the vehicle is running, and a fastening spring that presses the bottom upper surface of the rail 6 and fastens it to the sleeper 7. Is equipped with. The rail fastening device 8 shown in FIGS. 1 and 2 uses, for example, a spring clip as a fastening spring and presses the bottom of the rail 6 by the elastic force of the spring clip to fasten the rail 6 to the sleeper 7. It is a wire spring type rail fastening device.

The ballast 9 is a structure that supports the sleeper 7 with a ballast layer. The track bed 9 is a ballast track bed constituted by a ballast layer in which a ballast ballast 10 and an artificial ballast 11 are laminated, and the load is dispersed and transmitted to the roadbed 4. The roadbed 9 has a roadbed thickness, which is the distance from the underside of the sleepers 7 to the roadbed surface, of 150 to 250 mm or more depending on the railroad grade in the case of conventional lines, and in the case of Shinkansen (general section (earth roadbed section) ) Is 300 mm or more.

The ballast ballast 10 is a granular body such as crushed stone that is spread between the sleeper 7 and the roadbed 4. The ballast ballast 10 is, for example, a stone obtained by crushing hard rock such as granite, quartzite, basalt or andesite into a size of about 15 to 70 mm by a crusher. The ballast ballast 10 has a specific gravity of 2.5 to 3.0 g/cm ³ and a particle size of 19.1 to 63.5 mm.

The artificial ballast 11 shown in FIGS. 1 and 2 is a member that mixes with the ballast ballast 10 to form the ballast 9. As shown in FIG. 3, the artificial ballast 11 has a polyhedral shape having a plurality of smooth plane portions 11c, and is a solid body surrounded by four or more planes. The artificial ballast 11 shown in FIG. 4 has a hexahedral shape having six quadrangular smooth flat surfaces 11c. The artificial ballast 11 includes a plurality of apex portions 11a, a side portion (ridge line portion) 11b of a straight line connecting the apex portions 11a, and a flat surface portion 11c surrounded by the side portions 11b. The artificial ballast 11 is, for example, a polyhedron such as a rectangular parallelepiped (hexahedron) in which all planes are rectangular (rectangular) or a cube (regular hexahedron) in which all planes are square. The artificial ballast 11 has substantially the same size as the ballast ballast 10, and the length of the side portion 11b is 19.1 to 63.5 mm so as to be within the grain size range of the ballast ballast 10, and the impact load reduction effect when passing the train. From the viewpoint of, 50 to 60 mm is particularly preferable. The artificial ballast 11 has a specific gravity of 2.5 to 3.0 g/cm ^3, which is substantially the same as that of the ballast ballast 10. The artificial ballast 11 reciprocates while the corners of the ballast ballast 10 are in contact with the flat surface portion 11c while sliding between the artificial ballasts 11, so that the ballast ballast 10 reciprocates to absorb the impact load generated when the train passes. It is preferable that the flat portion 11c is a member having a certain degree of hardness and capable of maintaining a smooth state. The artificial ballast 11 is a block body made of metal, synthetic resin, or geopolymer concrete. The artificial ballast 11 is made of, for example, duralumin, which is a kind of aluminum alloy when made of metal, epoxy resin which is a kind of thermosetting resin when made of synthetic resin, and roman concrete when made of geopolymer concrete. It is a kind and is preferably a cured product obtained by mixing coal ash (fly ash), blast furnace slag fine powder, silica fume, water glass (alkali silicate solution) and, if necessary, aggregates and polycondensation. The artificial ballast 11 is formed into a block body by cutting a columnar member or a rod-shaped member made of metal or synthetic resin having a quadrangular cross section into a predetermined length in the case of machining, for example. Is formed into a block by pouring metal, synthetic resin or geopolymer concrete into a polyhedral mold.

The mixed layer 12 shown in FIGS. 1 and 2 is a layer in which the ballast ballast 10 and the artificial ballast 11 are mixed. The mixed layer 12 is formed by randomly mixing the roadbed ballast 10 and the artificial ballast 11. The mixed layer 12 attenuates and reduces the displacement behavior component in the low frequency region of the impact load when the train 1 passes, thereby preventing deterioration of the ballast layer. The mixed layer 12 is formed below the sleeper 7 with a predetermined depth and substantially the same length and width as the sleeper 7.

Since the magnitude of the impact load transmitted from the sleeper 7 to the roadbed 9 increases as the mixed layer 12 approaches the sleeper 7, it is advantageous to construct the mixed layer 12 as close to the sleeper 7 as possible. However, if the mixed layer 12 is constructed near the lower surface of the sleeper 7, the workability will be poor, and the height adjustment in the track maintenance after the work will be slightly difficult. Therefore, it is preferable that the mixed layer 12 is formed so as to have a depth D≧100 mm from the lower surface of the sleeper 7. In addition, in the mixed layer 12, at the same time that the ballast ballast 10 between the lower surface of the sleeper 7 and the wear progresses after construction, the ballast ballast 10 is closely sandwiched between the artificial ballasts 11 to stabilize the contact structure. Causes a large initial settlement. Therefore, the mixed layer 12 preferably has a depth D of 100 to 200 mm from the lower surface of the sleeper 7 in consideration of this initial subsidence amount.

When the mixing amount of the artificial ballasts 11 per sleeper 7 is less than 80, the mixing layer 12 becomes sparsely distributed, and the mixing layer 12 cannot be formed on the entire surface of the sleeper lower surface, and the impact load is reduced. There is a problem that it becomes impossible to suppress. On the other hand, the mixed layer 12 needs to be formed in the range of depth D≦200 mm from the lower surface of the sleeper 7, and the construction range is limited. Therefore, even when the mixed layer 12 is constructed up to the immediate vicinity of the sleeper 7, it is artificial. The amount of the ballast 11 mixed is approximately 200 as the upper limit value, and 120 as the upper limit value. Therefore, assuming that one layer of the mixed layer 12 is formed in the ballast layer, it is preferable that the mixing amount of the artificial ballast 11 per one sleeper 7 is in the range of 80 to 120.

Next, the principle of the artificial ballast according to the first embodiment of the present invention will be described.
In the following, the principle of damping the impact load of the artificial ballast will be explained as a hypothesis.
In the case of the conventional artificial ballast, the structure is made of cement concrete having irregularities on the surface. Therefore, in the case of a conventional artificial ballast, the function of reducing the impact load by being caught by the unevenness of the surface and being repeatedly worn by the impact load during train passage causes wear to progress and the shape gradually rounds to reduce the impact load. It will be gone. On the other hand, in the case of the artificial ballast 11, since it is a homogeneous elastic body having the flat surface portion 11c, when an external force is applied to the artificial ballast 11, the relationship between the deformation amount (compression amount or elongation amount) and the load is changed by the elastic spring. It becomes an approximate linear (straight line). On the other hand, since the ballast ballast 10 that comes into contact with the flat surface portion 11c of the artificial ballast 11 has irregularities, the relationship between the deformation amount and the load is not linear according to the Hertz contact theory. For this reason, when the artificial ballast 11 that linearly deforms and the ballast ballast 10 that deforms non-linearly, excess or deficiency occurs in the transmission of load, and the tip end portion of the contact portion of the ballast ballast 10 largely violates. As a result, the impact load transmitted from the ballast ballast 10 to the artificial ballast 11 as an elastic wave does not match the amount of deformation, and a large loss occurs in the impact load at the contact portion between the ballast ballast 10 and the artificial ballast 11, resulting in a large impact load. The damping effect is exerted and the impact load is reduced.

Since the ballast layer is a granular body, it is considered that it functions as particles against vibration of impact load and has the same action as liquid. When the impact load is applied from the upper surface, when the impact load passes through the ballast layer, it is transmitted as waves inside the ballast layer, but at the contact point between the ballast ballast 10 and the artificial ballast 11, the impact load is converted into displacement amplitude. .. The displacement amplitude at the contact point becomes a new vibration reduction like Huygens's principle in wave propagation in liquid, and the directionality is lost at that time. For example, assuming a case where a train impact load is applied to the upper surface of a 30 cm rectangular parallelepiped ballast layer, the shock load is mainly applied to the upper surface of the rectangular parallelepiped as vertical vibration, but not to the bottom surface of the ballast layer, but to the side. The shock waves are evenly transmitted to the four surfaces as if the water pressure was evenly applied. In a typical material, whereas under load at the lower surface 1 side, for receiving a load in total five surfaces of the bottom surface and the side surface in the ballast load level is significantly reduced. When the rectangular artificial ballast 11 is mixed in the ballast layer, the artificial ballast 11 functions as a device for transmitting the load further to the side with respect to the vibration in the low frequency region.

When the ballast ballast 10 above the mixed layer 12 and the ballast ballast 10 inside the mixed layer 12 are worn and become round at the time of initial subsidence, a round worn ballast is formed in the valleys between the flat surface portions 11c of the plurality of artificial ballasts 11. The structure is such that the ballast 10 is sandwiched. When the low-frequency displacement behavior acts from above the ballast layer, the worn ballast ballast 10 slides up and down in the valleys of the flat portions 11c of the adjacent artificial ballasts 11 to push the force laterally. The displacement amplitude is absorbed by the reciprocating motion of the ballast ballast 10 in the valley between the flat surface portions 11c of the adjacent artificial ballasts 11, and the displacement amplitude is not transmitted to the layer below the mixed layer 12. The ballast layer is originally stable by friction, but by introducing the artificial ballast 11 having the smooth flat surface portion 11c into the ballast layer, the displacement in the low frequency region is absorbed, and the impact during train passage is absorbed. The load is reduced.

Next, a roadbed improvement method according to the first embodiment of the present invention will be described.
(At the time of updating the track)
The improved construction method #100 shown in FIG. 4 is a construction method for improving the roadbed 9 that supports the sleepers 7 by the ballast layer. The improved construction method #100 is carried out when the existing roadbed 9 is replaced, as shown in FIG. As shown in FIG. 4, the improved construction method #100 includes an excavation process #110, a mixed layer formation process #120, and a roadbed rearrangement process #130. The excavation step #110 is a step of excavating the ballast 10 from the roadbed 9. In the excavation process #110, as shown in FIG. 5(A), the existing ballast ballast 10 within the range of the depth D≧200 mm from the lower surface of the sleeper 7 is scraped from the road bed 9. The mixed layer forming step #120 shown in FIG. 4 is a step of forming the mixed layer 12 in which the artificial ballast 11 and the ballast ballast 10 are mixed. In the mixed layer forming step #120, as shown in FIG. 5(B), the ballast ballast 10 scraped out in the excavating step #110 is collected, and a new ballast ballast 10 and artificial ballast 11 are randomly mixed. Is scraped onto the lower surface of the sleeper 7 and filled, and a new ballast ballast 10 is scraped onto the mixed layer 12 and filled. In the mixed layer forming step #120, the mixed layer 12 is formed within the range of depth D=100 to 200 mm from the lower surface of the sleeper 7, and the mixing amount of the artificial ballast 11 per one sleeper 7 is 80. The mixed layer 12 is formed so as to have 120 pieces. The roadbed rearranging process #130 shown in FIG. 4 is a process of preparing the roadbed 9 into a predetermined roadbed cross section. In the roadbed rearrangement process #130, as shown in FIG. 5C, after the sticking work of putting the ballast ballast 10 and the artificial ballast 11 under the sleepers 7 is performed, the roadbed 9 is initially vibrated by vibration. Subsidence is given to stabilize the orbit 5, and the height of the orbital surface is adjusted.

(At the time of new dojo)
The improved construction method #100 shown in FIG. 6 is implemented when a new roadbed 9 is laid as shown in FIG. As shown in FIG. 6, the improved construction method #100 includes a mixed layer forming step #140, a rail laying step #150, and a roadbed rearranging step #160. The mixed layer forming step #140 is a step of forming the mixed layer 12 in which the artificial ballast 11 and the ballast ballast 10 are mixed. In the mixed layer forming step #140, as shown in FIG. 7A, first, a new roadbed ballast 10 is sprayed on the roadbed 4 with a predetermined thickness. Next, in the mixed layer forming step #140, a mixture of the new ballast ballast 10 and the artificial ballast 11 randomly mixed is sprayed on the ballast ballast 10 sprayed on the roadbed 4. Then, in the mixed layer forming step #140, a new ballast ballast 10 is sprinkled on the mixed layer 12. In the mixed layer forming step #140, the mixed layer 12 is formed within the depth D=100 to 200 mm from the lower surface of the sleeper 7, and the mixing amount of the artificial ballast 11 per one sleeper 7 is 80. The mixed layer 12 is formed so as to have 120 pieces. The rail laying step #150 shown in FIG. 6 is a step of laying the rail on the roadbed 9. In the rail laying step #150, as shown in FIG. 7(B), ladder-shaped rails in which the left and right rails 6 are fastened to the sleepers 7 are laid on the roadbed 9. The roadbed rearrangement process #160 shown in FIG. 6 is a process of preparing the roadbed 9 into a predetermined roadbed cross section. In the roadbed rearranging step #190, as shown in FIG. 7(C), a packing operation of putting the ballast ballast 10 and the artificial ballast 11 under the sleeper 7 is performed to adjust the height of the raceway surface.

The artificial ballast and the roadbed according to the first embodiment of the present invention and the improved construction method thereof have the following effects.
(1) In the first embodiment, the artificial ballast 11 has a polyhedral shape having a plurality of smooth flat surface portions 11c. Therefore, a large loss occurs in the impact load at the contact portion between the ballast ballast 10 having unevenness on the surface and the artificial ballast 11 having the smooth flat portion 11c, and the impact load damping effect is exerted to reduce the impact load. be able to. As a result, the impact load component at the time of passing the train is significantly reduced, and it is possible to prevent the track subsidence, and it is possible to prevent the deterioration of the ballast layer and reduce the cost required for the maintenance and management of the ballast track. ..

(2) In the first embodiment, the artificial ballast 11 has a hexahedral shape having six quadrangular smooth flat surfaces 11c. For this reason, the impact load component at the time of passing a train can be greatly reduced by the hexahedral artificial ballast 11 which is easy to manufacture and has a simple structure, and the deterioration of the ballast layer can be easily prevented.

(3) In the first embodiment, the artificial ballast 11 has substantially the same size as the ballast ballast 10. Therefore, by mixing with the ballast ballast 10, the sleepers 7 can be evenly supported like the ballast ballasts 10, and the train load transmitted to the sleepers 7 is widely and evenly distributed on the roadbed 4 to have a constant track structure. The elastic force can be applied.

(4) In the first embodiment, the artificial ballast 11 is a block body made of metal, synthetic resin or geopolymer concrete. Therefore, the artificial ballast 11 can be easily manufactured by cutting a columnar member or a rod-shaped member made of metal or synthetic resin into a predetermined length. Further, the artificial ballast 11 can be easily manufactured by pouring metal, synthetic resin, or geopolymer concrete into the mold.

(5) In this first embodiment, the ballast 9 is provided with the mixed layer 12 in which the artificial ballast 11 and the ballast ballast 10 are mixed. Therefore, the displacement behavior component in the low frequency region of the impact load when the train passes can be attenuated and reduced, and the deterioration of the ballast layer can be prevented. In addition, the track 5 can be improved at low cost by a simple construction that can be done in a short time.

(6) In the first embodiment, the mixed layer 12 has a depth of 100 to 200 mm from the lower surface of the sleeper 7. Moreover, in this 1st Embodiment, the mixing amount of the artificial ballast 11 per 1 sleeper is 80-120 pieces. Therefore, the impact load component when passing the train can be significantly reduced.

(Second embodiment)
In the following, the same parts as those shown in FIGS. 1 to 3 will be assigned the same reference numerals and detailed description thereof will be omitted.
The artificial ballast 11 shown in FIG. 8 has a triangular prism shape having two substantially parallel triangular smooth bottom surfaces 11d and three quadrangular smooth side surfaces 11e, and is surrounded by four or more flat surfaces. It is a solid. The artificial ballast 11 includes a plurality of apex portions 11a, a side portion (ridge line portion) 11b of a straight line connecting the apex portions 11a, and a bottom surface portion 11d and a side surface portion 11e surrounded by the side portions 11b. The artificial ballast 11 is, for example, a prism such as a triangular prism having two bottom surfaces formed by triangles and three side surfaces formed by quadrangles, or a regular prism such as two triangular bases formed by equilateral triangles and three bottom surfaces formed by quadrangles. Is. The artificial ballast 11 is a block body made of metal, synthetic resin, or geopolymer concrete, has substantially the same size as the ballast ballast 10, and has substantially the same specific gravity as the ballast ballast 10. The artificial ballast 11 is formed into a block body by cutting a metal or synthetic resin columnar member or rod-shaped member having a triangular cross-section into a predetermined length in the case of machining, for example. Is formed into a block by pouring metal, synthetic resin or geopolymer concrete into a prismatic mold.

The artificial ballast and the roadbed according to the second embodiment of the present invention and the improved construction method thereof have the following effects in addition to the effects of the first embodiment.
In this second embodiment, the artificial ballast 11 has a triangular prism shape having two substantially parallel triangular smooth bottom surfaces 11d and three quadrangular smooth side surfaces 11e. For this reason, the impact load component at the time of passing the train can be greatly reduced by the prismatic shape of the structure which is easy to manufacture and has a simple structure, and the deterioration of the ballast layer can be easily prevented.

(Third Embodiment)
The sleeper 7 shown in FIGS. 9 and 10 is an elastic sleeper having a cushioning member 7a on the bottom surface. The sleeper 7 is installed for the purpose of reducing vibration noise and labor saving of track maintenance. The sleeper 7 shown in FIGS. 9 and 10 is, for example, a ballast bed elastic sleeper used in a ballasted track, which reduces vibration generated when the train 1 passes and prevents the ballast ballast 10 from becoming fine. .. The sleeper 7 includes a cushioning member 7a and the like.

The cushioning member 7a is a member that relieves the impact acting on the ballast layer. The cushioning member 7 a is sandwiched between the sleeper 7 and the roadbed 9. The cushioning member 7a is, for example, an elastic body such as polyethylene, foamed polyurethane, foamed polyethylene, synthetic rubber, natural rubber, urethane rubber or styrene rubber, and is preferably an elastic sheet made of a high damping material having a thickness of about 15 mm. The cushioning member 7a is attached to the bottom surface of the sleeper 7. The mixed layer 12 is formed within the range of depth D=100 to 200 mm from the lower surface of the sleeper 7 (the lower surface of the buffer member 7a).

The artificial ballast and the roadbed according to the third embodiment of the present invention and the improved construction method thereof have the following effects in addition to the effects of the first and second embodiments.
The third embodiment is an elastic sleeper having a cushioning member 7a on the bottom surface of the sleeper 7, which cushions the impact acting on the ballast layer. For this reason, the track subsidence phenomenon can be greatly reduced by additionally using a construction method in which a cushioning member 7a such as an elastic sheet made of a high damping material is attached to the lower surface of the sleeper 7.

Next, an embodiment of the present invention will be described.
In order to confirm the effect of reducing the impact load when passing the train by the artificial ballast 11 shown in FIGS. 1 to 3, a weight drop impact loading experiment was conducted. The weight drop impact loading test was carried out using a track dynamic loading test device at the Hino Civil Engineering Laboratory of the Railway Technical Research Institute. In the weight drop impact loading test, the track dynamic loading test device 20 shown in FIGS. 11 to 14 strokes an impact load of 200 kN on average to the left and right rails 6 on the central sleeper 7 shown in FIG. It was repeatedly loaded at a height of 12 mm and a vibration frequency (fall frequency) of 0.2 Hz.

The track 5 shown in FIGS. 11 to 14 is a real Shinkansen track, the rail 6 is a 60 kg rail, and the sleeper 7 is a standard rail 3H sleeper. As shown in FIG. 11, the track 5 is a track formed by connecting left and right rails 6 to three sleepers 7 by a rail fastening device 8 and having a width of 3000 mm and a depth of 6000 mm formed on the construction base surface (roadbed). It was laid in the pit so that the thickness of the ballast layer was 350 mm from the underside of the sleeper.

The track dynamic load test apparatus 20 shown in FIGS. 11 to 14 is a test apparatus that loads a dynamic or static axial load on a full-scale track 5. Here, the unit shown in FIGS. 11 to 13 is mm. The track dynamic load test apparatus 20 is used for clarifying the settlement characteristics of a bedded track (ballast track) and for confirming the durability of a new track structure. The track dynamic load test apparatus 20 includes a weight 21 shown in FIGS. 12 to 14, laser displacement meters 22A and 22B shown in FIGS. 11 and 14, a frame 23 shown in FIG. 11, and an acceleration sensor shown in FIG. 24A, 24B, etc. are provided. The weight 21 shown in FIGS. 12 to 14 is a member that applies an impact load to the track 5. The weight 21 shown in FIGS. 12 to 14 is a box-shaped Shinkansen orbit weight having a length of 1800 mm×a width of 400 mm×a height of 200 mm. The laser displacement meter 22A is a device that measures the amount of subsidence at one end of the sleeper 7, and the laser displacement meter 22B is a device that measures the amount of subsidence at the other end. The frame 23 shown in FIG. 11 is a member installed on a fixed point while supporting the laser displacement meters 22A and 22B. The acceleration sensors 24A and 24B are devices that detect acceleration in the ballast layer. As shown in FIG. 14, the acceleration sensors 24A and 24B are arranged immediately below the left and right rails 6 at different depths. The orbit dynamic load test apparatus 20 repeats the operation of raising the weight 21 shown in FIGS. 12 and 13 by the hydraulic actuator and then dropping the weight 21 onto the rail 6 to obtain a sharp pulse-like impact load. Is repeatedly loaded on the track 5 to perform a weight drop test. The orbit dynamic load test apparatus 20 measures the ballast acceleration in the ballast layer due to impact loading by the acceleration sensors 24A and 24B, and measures the subsidence amount by the laser displacement meters 22A and 22B.

The graph shown in FIG. 15 shows four measurement points at a depth of 100 mm and 200 mm from the lower surface of the sleeper 7 when an impact load is repeatedly applied to the track 5 by the track dynamic load test device 20 shown in FIGS. 11 to 14. 3 is an acceleration spectrum waveform of an average value of accelerations acting on the ballast layer measured by the acceleration sensors 24A and 24B. The vertical axis shown in FIG. 15 is the ballast acceleration (m/s ² ) and the horizontal axis is the frequency (Hz). The acceleration spectrum waveform was obtained based on the loading waveforms at each measurement point four times in a relatively stable state after the initial loading on the ballast layer was completed.

Comparative Example 1 shown in FIG. 15 is an experimental result in the case where the ballast layer of the track 5 is a non-countermeasure ballast layer formed by only the normal ballast ballast 10. Comparative Example 2 is an experimental result in the case where a part of the ballast layer of the track 5 is a mixed layer of a normal ballast ballast 10 and a conventional artificial ballast. Here, the conventional artificial ballast is an artificial block made of cement concrete having irregularities on the surface. This conventional artificial ballast is a high-strength fiber reinforced block (trade name: momokocube) manufactured by Toyo Road Kogyo Co., Ltd. (manufactured by Ayaha Kogyo Co., Ltd.) having a length of 60 mm, a width of 60 mm, and a height of 50 mm. From the lower surface of the central sleeper 7 shown in Fig. 140, 140 pieces were thrown within a depth range of 100 to 200 mm.

Example 1 is an experimental result when a part of the ballast layer of the track 5 is a mixed layer 12 of a normal ballast ballast 10 and an artificial ballast 11. Here, the artificial ballast 11 is a rectangular block made of duralumin having a length of 60 mm, a width of 60 mm, and a height of 50 mm, and is within a range of a depth of 100 to 200 mm from the lower surface of the central sleeper 7 shown in FIGS. 11 and 12. Added 140 pieces. The second embodiment is a case where a part of the ballast layer of the track 5 is the mixed layer 12 of the normal ballast ballast 10 and the artificial ballast 11 as in the first embodiment, and the sleeper 4 has a high damping on the bottom surface. It is an experimental result when it is an elastic sleeper provided with a material. Here, low-repulsion rubber (NXB-365 manufactured by Irumagawa Rubber Co., Ltd.) was used as the high damping material.

As shown in FIG. 15, in the case of Comparative Example 1, it was confirmed that there was a large response peak in the low frequency region and that the ballast ballast 10 had a large movement. In the case of Comparative Example 2, the peak of the response in the low frequency region was lower than that of Comparative Example 1, but it was confirmed that a large movement occurred in the ballast ballast 10 as in Comparative Example 1. .. On the other hand, in the case of Example 1, by mixing the artificial ballast 11 into the normal ballast ballast 10, the response in the low frequency region is significantly reduced as compared with Comparative Examples 1 and 2, and the mixing layer 12 The effect of suppressing the displacement behavior in the low frequency region was confirmed. In the case of Example 2, it was confirmed that the use of the elastic sleeper for the sleeper 7 has the effect of further suppressing the displacement behavior in the low frequency region as compared with Example 1.

The graph shown in FIG. 16 is a settling curve showing the change over time in the sinking amount of the track 5 when an impact load is repeatedly applied to the track 5 by the track dynamic load test device 20 shown in FIGS. 11 to 14. The vertical axis shown in FIG. 16 is the subsidence amount (mm), and the horizontal axis is the number of times of loading (times). Comparative Example 3 shown in FIG. 16 is a case where the ballast layer of the track 5 is formed only by the normal ballast ballast 10 and the sleeper 4 is an elastic sleeper having a high damping material on the bottom surface. These are the experimental results. Here, the same low repulsion rubber (NXB-365 manufactured by Irumagawa Rubber Co., Ltd.) as in Example 1 was used as the high damping material.

As shown in FIG. 16, in the case of Comparative Example 1, a very large initial settlement occurred, and it was confirmed that the settlement amount increases according to the number of times of loading. In the case of Comparative Example 1, the loading frequency is up to 3000 times as shown in FIG. 16, but it was confirmed that the settlement amount does not converge even when the loading frequency exceeds 10,000 times. In the cases of Comparative Examples 2 and 3, although the initial subsidence was lower than that of Comparative Example 1, it was confirmed that the effect of suppressing the orbital subsidence was insufficient. On the other hand, in the case of Example 1, it was confirmed that the subsidence was substantially subsided after the initial loading of 1000 times, which corresponds to the initial loading. In the case of Example 2, by using the high damping material together, it was confirmed that the subsidence hardly occurs after the loading number of about 1000 times, and the remarkable effect of suppressing the track subsidence almost completely. From the above, it was confirmed that orbit subsidence can be suppressed by mixing the artificial ballast 11 inside the ballast layer. In addition, it was confirmed that the track subsidence could be further suppressed by using it together with elastic sleepers.

(Other embodiments)
The present invention is not limited to the embodiments described above, and various modifications and changes can be made as described below, and these are also within the scope of the present invention.
In this embodiment, the case where the artificial ballast 11 is a block made of duralumin has been described as an example, but the present invention can be applied to the case where the artificial ballast 11 is another aluminum alloy having high strength other than duralumin. Further, in the second embodiment, the case where the artificial ballast 11 has a triangular prism shape has been described as an example, but the present invention can be applied to the case where the artificial ballast 11 has a triangular pyramid shape or a quadrangular pyramid shape.

1 Train 1A Vehicle 2 Vehicle 3 Wheel 4 Roadbed 5 Track 6 Rail 7 Sleeper 7a Buffer member 8 Rail fastening device 9 Roadbed 10 Roadbed ballast 11 Artificial ballast 11a Top 11b Side 11c Plane 11d Bottom (plane)
11e Side surface portion (flat surface portion)
12 Mixed Layer 20 Orbital Dynamic Loading Test Device 21 Weights 22A, 22B Laser Displacement Meter 23 Frame 24A, 24B Accelerometer

Claims (10)

An artificial ballast that mixes with a ballast ballast to form a ballast,
It is a polyhedron shape having a plurality of smooth flat parts on the entire surface ,
An aluminum alloy of substantially the same size as the ballast ballast, a block body made of thermosetting resin or geopolymer concrete ,
In a state where the corner portion of the ballast ballast is in contact with the plane portion, the ballast ballast reciprocates while sliding on the plane portion to absorb the impact load generated when the train passes.
An artificial ballast characterized by. The artificial ballast according to claim 1,
A hexahedron shape having six quadrangular smooth plane portions,
An artificial ballast characterized by. The artificial ballast according to claim 1,
A triangular prism shape having two substantially parallel triangular bottom surfaces and three quadrangular smooth side surfaces;
An artificial ballast characterized by. A ballast for supporting a support by a ballast layer,
A mixed layer in which the artificial ballast according to any one of claims 1 to 3 and the ballast ballast are mixed,
The roadbed characterized by. In the track according to claim 4 ,
The mixed layer, when the support is a sleeper, the depth from the lower surface of the sleeper is within the range of 100 to 200 mm,
The roadbed characterized by. In the bed according to claim 4 or claim 5 ,
The mixed layer, when the support is sleepers, the mixing amount of the artificial ballast per one sleeper is 80 to 120,
The roadbed characterized by. In the roadbed according to any one of claims 4 to 6 ,
The support is an elastic sleeper having a cushioning member on the bottom surface for cushioning the impact acting on the ballast layer.
The roadbed characterized by. A method for improving a ballast that improves a ballast that supports a support by a ballast layer,
A mixed layer forming step of forming a mixed layer in which the artificial ballast according to any one of claims 1 to 3 and the ballast ballast are mixed.
An improved construction method for roadbeds. In the roadbed improvement method according to claim 8 ,
The mixed layer forming step includes a step of forming the mixed layer within a range of a depth of 100 to 200 mm from a lower surface of the sleeper when the support is a sleeper,
An improved construction method for roadbeds. In the roadbed improvement method according to claim 8 or 9 ,
The mixed layer forming step includes a step of forming the mixed layer so that when the support is a sleeper, the mixing amount of the artificial ballast per one sleeper is 80 to 120. ,
An improved construction method for roadbeds.