JP4009275B2 - Roadbed repair method and roadbed - Google Patents

Description

  The present invention relates to a roadbed repair method and a roadbed that are applied to a labor-saving track that supports sleepers by a packed bed formed on a roadbed made of clay.

  In this kind of labor-saving track, the water pressure fluctuation on the surface of the roadbed caused by traffic loads such as trains is less than 1 m at most, and the pressure itself is not so great as to destroy the soil. However, in places where there is a phase difference in the dynamic displacement between the packed bed and the roadbed, or where there is originally a gap, the restraint pressure of the mud of the roadbed (hereinafter referred to as the roadbed soil) is insufficient and the strength is low. Since it becomes extremely low, even if there is such a fluctuation in water pressure, it will flow out if there is a water channel. Then, on the surface of the roadbed, a cavity is generated in the trace where the roadbed soil has flowed and flowed out, and it gradually grows, so that a roadbed deformation occurs.

  Conventionally, when a roadbed deformation has occurred in this way, the roadbed deformation has been repaired by filling the cavity with crushed stone or placing concrete into the cavity.

  However, in this case, the mud is often sprayed from the lower surface of crushed stone or concrete filled in the cavity, and the generation of the cavity is repeated. Therefore, the repair effect of the roadbed deformation becomes temporary, and there is an inconvenience that it cannot be said that the repair is effective in the long term.

  This applies not only to labor-saving tracks, but also to roads that receive traffic loads such as automobiles.

  In view of such circumstances, an object of the present invention is to provide a roadbed repair method and a roadbed capable of maintaining the repair effect of roadbed deformation over a long period on a labor-saving track or road.

First, the invention according to claim 1 is a roadbed repair method for repairing a roadbed deformation by filling a cavity generated on the surface of the roadbed, and after injecting a powdery high plastic material into the cavity, By injecting a repair filler into the cavity, a part of the high plastic material is replaced with the repair filler, and a road surface protective layer having a consistency property of 10 or less made of the high plastic material is provided. It is characterized by being formed integrally with the roadbed.
The invention according to claim 2 is characterized in that the high plastic material is bentonite powder.
The invention according to claim 3 is characterized in that when the high plastic material is injected into the cavity, mist of water is sprayed so as to be uniformly mixed with the high plastic material in a fine particle state.
The invention according to claim 4 is repaired by the roadbed repair method according to any one of claims 1 to 3 .

  ADVANTAGE OF THE INVENTION According to this invention, the mud from the surface of a roadbed can be prevented, and generation | occurrence | production and growth of a new cavity in the surface of a roadbed can be prevented. Therefore, it is possible to maintain the repair effect of roadbed deformation over a long period of time on labor-saving tracks and roads. Moreover, since the high plastic material injected into the cavity is in the form of powder, even if the cavity is large, a small amount of high plastic material is sufficient. As a result, material costs and construction costs can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1A, the labor-saving track 1 has a roadbed 2 made of viscous soil, and a packed bed 5 is formed on the upper side of the roadbed 2. A plurality of sleepers 6 are arranged on the upper side of the packed bed 5 at predetermined intervals along a direction perpendicular to the paper surface of FIG. However, it is mounted so as to extend in a direction perpendicular to the paper surface of FIG. Furthermore, a large number of ballasts 9 are laid around the packed bed 5 and the sleepers 6 on the upper side of the roadbed 2.

  In this labor-saving track 1, as shown in FIG. 1A, when a cavity 4 is generated on the surface of the roadbed 2 due to a traffic load such as a train, the roadbed is repaired according to the following procedure. .

  That is, as a primary construction, bentonite powder, which is a powdery high plastic material having water absorption swellability, is poured into the cavity 4. For this purpose, as shown in FIG. 1 (a), a bentonite injection pipe 20 is inserted so as to reach the cavity 4 from directly above the cavity 4, and an air pressure source (not shown) such as a small compressor or compression is installed. The bentonite powder is blown into the cavity 4 together with air from the bentonite injection pipe 20 using an air cylinder or the like. Then, bentonite powder is supplied to the cavities 4 and dispersed.

  At this time, it is ideal to inject as much bentonite powder as possible into the cavity 4, but normally the inner wall of the cavity 4 is moist and bentonite powder adheres to the inner wall and is naturally coated. Even if the inside is not filled with bentonite powder, if the bentonite powder reaches a certain thickness (for example, about 5 mm), further growth of the cavity 4 can be prevented. Therefore, even if the cavity 4 is large, a small amount of bentonite powder is sufficient, so that material costs and construction costs can be suppressed.

Next, the process proceeds to secondary construction, and cement asphalt mortar, which is a filler for repair, is injected into the cavity 4. For this purpose, as shown in FIG. 1 (b), a mortar injection pipe 21 and a bentonite discharge pipe 22 are installed so as to reach the cavity 4 from directly above the cavity 4, and the cement asphalt is inserted from the mortar injection pipe 21. Placing mortar. Then, cement asphalt mortar flows into the cavity 4 and is discharged from the bentonite discharge pipe 22 in the form of pushing out part of the bentonite powder injected in the primary construction.

  Thereafter, when a predetermined curing time has elapsed, the cement asphalt mortar is hardened in the cavity 4 by a hydration reaction, and the cavity filling layer 15 is formed. Further, a roadbed surface protective layer 13 made of bentonite is formed in close contact with the roadbed 2 between the roadbed 2 and the cavity filling layer 15. Here, the roadbed repair is completed.

  Therefore, the roadbed surface protective layer 13 can prevent the roadbed soil from fluidizing and flowing out. Further, the roadbed surface protective layer 13 absorbs a phase difference between the dynamic deformation of the filling layer 5 and the dynamic deformation of the roadbed soil, so that a new cavity (not shown) is temporarily formed on the surface of the roadbed 2. Can be prevented from occurring. In addition, as the second construction, by injecting cement asphalt mortar (a filler for repairing), the supporting force of the roadbed 2 can be recovered while preventing the growth of the cavity 4. Furthermore, since the roadbed surface protective layer 13 has water absorption swelling property, even if the roadbed soil flows out and a new cavity is generated on the surface of the roadbed 2, the roadbed surface protective layer 13 absorbs and swells. Since the cavity is filled, the growth of the cavity can be prevented. As a result, it becomes possible to maintain the repair effect of roadbed deformation over a long period of time.

  In order to confirm the above-described effect, the consistency characteristic Ic is Ic = 0.73 WL−Ip as an index representing the consistency (hardness and fluidity) of the roadbed surface protective layer 13 by the plasticity index Ip and the liquid limit WL. Defined. For example, when this is applied to the Japan unified soil classification, Ic ≦ 14.6 is clay and Ic ≧ 14.6 is silt. And when this consistency characteristic Ic was changed within the range of -7-13, it was calculated | required by experiment how the outflow amount of a roadbed soil by a train load changes.

  As a result, as shown in FIG. 2, it was found that the outflow amount of the roadbed soil is very sensitive to the consistency characteristic Ic of the roadbed surface protective layer 13. That is, when the consistency characteristic Ic of the roadbed surface protective layer 13 was 13, the outflow amount of the roadbed soil was over 100 g. On the other hand, when the consistency characteristic Ic of the roadbed surface protective layer 13 is 12, the outflow amount of the roadbed soil is about 20 g, and when the consistency characteristic Ic of the roadbed surface protective layer 13 is 10, the outflow amount of the roadbed soil is It dropped rapidly to about 5 g. Moreover, when the consistency characteristic Ic of the roadbed surface protective layer 13 was 5 or less, the result that the outflow amount of the roadbed soil became zero was obtained. Therefore, the outflow amount of the roadbed soil is greatly reduced by the roadbed surface protective layer 13 made of a high plastic material. In particular, when the consistency characteristic Ic of the roadbed surface protective layer 13 is 5 or less, it is changed to the road bed 2 at the train load level. It became clear that no shape occurred.

  In the above-described embodiment, when the bentonite powder is injected into the cavity 4, the bentonite injection pipe 20 is inserted downward from directly above the cavity 4, but when the cavity 4 is biased, as shown in FIG. In addition, the bentonite injection pipe 20 may be inserted almost horizontally from the side of the cavity 4.

  Further, in the above-described embodiment, the case where the bentonite injection pipe 20 is used alone when the bentonite powder is injected into the cavity 4 has been described. However, when the inner wall of the cavity 4 is not so wet, as shown in FIG. 4, a bent tube 23 is attached to the bentonite injection tube 20 as needed, and bentonite powder is discharged from the bentonite injection tube 20. At the same time, mist-like water can be sprayed from the spray tube 23. At this time, the bentonite powder discharged from the bentonite injection pipe 20 is uniformly mixed in the state of water and fine particles sprayed from the spray pipe 23 and reaches a predetermined moisture content, so that the bentonite powder is prevented from scattering into the surrounding environment. In addition, the bentonite powder can be filled in the cavity 4 with an appropriate water content ratio. Here, the front-rear positional relationship of the spray tube 23 with respect to the bentonite injection tube 20 may be either the bentonite injection tube 20 or the spray tube 23 forward, but as shown in FIG. If it is located further forward, it is advantageous in that water hardly adheres to the bentonite injection pipe 20. The spray tube 23 may or may not be fixed to the bentonite injection tube 20.

  Moreover, in the above-mentioned embodiment, after injecting bentonite powder into the cavity 4 as primary construction, the cement asphalt mortar was injected into the cavity 4 as secondary construction. However, when the cavity 4 is not so large, the construction period can be shortened by omitting the secondary construction.

  Moreover, although the above-mentioned embodiment demonstrated the case where bentonite powder was used as a highly plastic material, lime powder, cement powder, etc. can be substituted. In particular, when the cavity 4 is large, a mixture of bentonite powder and sand can be used. In this case, since the sand in the mixture develops strength and the bentonite powder in the mixture functions as an adhesive (binder), both effects of void repair and mud prevention are expected.

  In the above-described embodiment, cement asphalt mortar is used as a repair filler, but repair fillers other than cement asphalt mortar (for example, sand, gravel, etc.) may be substituted.

  In the above-described embodiment, the labor-saving trajectory has been described. However, the present invention can also be applied to a road that receives a traffic load such as an automobile.

It is process drawing which shows one Embodiment of the roadbed repair method which concerns on this invention. It is a graph which shows the relationship between the consistency characteristic of a roadbed surface protective layer in a roadbed deformation reproduction test, and a roadbed soil runoff amount. It is process drawing which shows another embodiment of the roadbed repair method which concerns on this invention. It is sectional drawing which shows the state which attached the spray pipe to the bentonite injection pipe.

Explanation of symbols

1 ... Labor-saving track 2 ... Roadbed 4 ... Cavity 5 ... Tensile layer 6 ... Sleeper 7 ... Rail 9 ... Ballast 13 ... Roadbed surface protective layer 15 ... Cavity packed layer 20 ... Bentonite Injection tube 21 …… Mortar injection tube 22 …… Bentonite discharge tube 23 …… Atomization tube

Claims (4)

A roadbed repair method for repairing roadbed deformation by filling a cavity generated on the surface of the roadbed,
After injecting a powdered high plastic material into the cavity, a part of the high plastic material is replaced with the repair filler by injecting a repair filler into the cavity. A roadbed repair method comprising: forming a roadbed surface protective layer having a consistency characteristic of 10 or less, comprising: The roadbed repair method according to claim 1, wherein the high plastic material is bentonite powder. 3. The roadbed repair method according to claim 1, wherein when the high plastic material is injected into the cavity, mist water is sprayed so as to be uniformly mixed with the high plastic material in a state of fine particles. . A roadbed repaired by the roadbed repair method according to any one of claims 1 to 3 .

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