Embankment restoration work construction method

Abstract

To provide a construction method for banking restoration, when restoring banking having a collapsed slope, which allows stability to be retained during operation of train and the like even if a temporary earth retaining work is omitted and can rapidly achieve a final restoration.SOLUTION: A construction method for restoring a banking 10 having a collapsed slope 11 performs a final restoration construction after an emergency construction. The emergency construction includes a step to shape the collapsed slope 11 into a stepwise shape, a step to lay a planar reinforcing material 21 along the shaped stepwise face, and a step to install sandbags 22 on the planar reinforcing material 21. The final restoration construction includes a step to gradually remove the sandbags 22, a step to insert rod-like reinforcing materials 23 toward the slope 11 from above the planar reinforcing material 21 at positions where the sandbags 22 are removed, and a step to apply a final restoration material 25 on the planar reinforcing material 21 after removing all the sandbags 22.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for carrying out restoration work on embankments where slopes have collapsed due to natural disasters or the like. [Background technology]

[0002] When a slope of an embankment formed for a railway or road collapses due to a large-scale natural disaster such as an earthquake or heavy rain, rapid restoration is required to quickly restore the transportation function. Usually, large sandbags are used for rapid restoration because they are cheap, easy to obtain, and easy to construct, but they are only temporary materials and cannot be used as permanent structures. If the embankment is reconstructed by covering it with soil while leaving the large sandbags in place, the large sandbags may be damaged in the soil, or the embankment may sink due to water paths formed in the gaps between the large sandbags during emergency work, making the embankment unstable. In addition, there is a problem that it is difficult to penetrate the solidification material when solidifying. Furthermore, the large sandbags may become a boundary surface during an earthquake, making the embankment unstable. Therefore, when carrying out actual restoration work, it is necessary to remove the large sandbags and carry out permanent restoration work.

[0003] However, if the large sandbags used as temporary materials are removed when the embankment slope has collapsed, the area would not be stable enough to withstand the weight of trains traveling on the railway, so the removal and full restoration must be carried out within a limited time outside of train operating hours.

[0004] Non-Patent Document 1 discloses an embankment restoration method that can shorten work time by combining large sandbags with geotextiles and leaving the large sandbags in place during main restoration to be used as structures.

[0005] On the other hand, when emergency restoration is performed using large sandbags and the large sandbags are removed during the actual restoration while trains or the like are running, temporary earth retaining structures using piles or steel sheet piles have been constructed in the past. Non-Patent Document 2 discloses a restoration method in which steel sheet piles are cast as a temporary earth retaining structure. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Yoshinori Mori, Hiroaki Miyatake, Tetsuya Kubo, and Genki Inoue: Research on New Disaster Recovery Technology for Large-Scale Landslides, 71st Annual Conference of the Japan Society of Civil Engineers, 2016 [Non-Patent Document 2] Daisuke Endo and Masaki Takita: Overview of damage caused by the 8.9 rainfall on the Tazawako Line and restoration of the Ryukawa Bridge, 69th Annual Conference of the Japan Society of Civil Engineers, 2014 Summary of the Invention [Problem to be solved by the invention]

[0007] However, although the short-term durability of the large sandbags has been confirmed in the method disclosed in Non-Patent Document 1, the long-term durability has not been confirmed. In addition, the method of temporarily retaining soil using piles and steel sheet piles as disclosed in Non-Patent Document 2 requires large-scale equipment such as a crane, which has the problem of requiring a lot of cost and construction time.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a construction method for embankment restoration work which, in the restoration of an embankment where a slope has collapsed, can maintain stability even when trains or the like are operating, even if temporary retaining work is omitted, and which enables full restoration to be completed quickly. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a construction method for restoring embankments where a slope has collapsed, comprising the steps of carrying out emergency construction and then carrying out main restoration work, the emergency construction including the steps of shaping the collapsed slope into a stepped shape, laying a planar reinforcement material along the shaped stepped surface, and placing sandbags on the planar reinforcement material, and the main restoration work including the steps of laying the sandbags on the planar reinforcement material. Withdraw a step of removing the sandbags from the top of the planar reinforcement material at the position where the sandbags were removed toward the slope; Repeating the step of removing the sandbag and the step of inserting the rod-shaped reinforcement material in this order; After removing all the sandbags A step of laying embankment reinforcement material on each step of the planar reinforcement material laid in a stepped manner; The method is characterized by including a process of applying the restoration material.

[0010] before The restoration work preferably includes a step of installing a drainage pipe for draining water inside the embankment to the outside of the embankment.

[0011] The sheet-like reinforcement may be a geotextile, and the rod-like reinforcement may be a reinforcing bar having an anchoring portion at a base end thereof for attachment to the sheet-like reinforcement. Effect of the Invention

[0012] According to the present invention, by laying a sheet-shaped reinforcement material on the back surface of the large sandbag during emergency restoration, and then removing the large sandbag in stages while fixing the sheet-shaped reinforcement material with a rod-shaped reinforcement material during main restoration, it is possible to maintain stability against the load of trains, etc. even after removing the large sandbag. Therefore, temporary retaining work requiring large-scale equipment, etc. can be omitted, and restoration work can be carried out quickly. [Brief description of the drawings]

[0013] [Figure 1] 1A to 1C are cross-sectional views for explaining a process sequence of emergency repair according to an embodiment of the present invention. [Diagram 2] 1A and 1B show a process of gradually removing sandbags in the restoration work according to an embodiment of the present invention, where (a) is a cross-sectional view and (b) is a side view. [Diagram 3] 1A and 1B show a process of inserting rod-shaped reinforcement materials into positions from which sandbags have been removed in the restoration work according to an embodiment of the present invention, where (a) is a cross-sectional view and (b) is a side view. [Figure 4] 1A and 1B show a state in which all sandbags have been removed and rod-shaped reinforcement materials have been inserted in the main restoration work according to the embodiment of the present invention, where (a) is a cross-sectional view and (b) is a side view. [Diagram 5] This is a cross-sectional view showing the state in which the restoration material has been installed on top of the planar reinforcement material after all the sandbags have been removed in the restoration work according to an embodiment of the present invention. [Figure 6]FIG. 6 is a cross-sectional view showing the state in which a restoration material different from that shown in FIG. 5 has been installed in the restoration work according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0015] 1 to 4 show an example of steps of a construction method for restoration work of an embankment according to an embodiment of the present invention. In the present embodiment, the construction procedure of restoration work will be described below using a railway embankment as an example.

[0016] When a slope 11 of an embankment 10 formed for a railway collapses due to a natural disaster such as an earthquake or heavy rain, as shown in FIG. 1(a), emergency restoration work is first carried out. FIGS. 1(b) to 1(e) show the steps of the emergency work. First, the collapsed slope 11 is shaped like steps (FIG. 1(b)), and planar reinforcement materials 21 are laid in a step-like manner along the shaped surface (FIG. 1(c)). As the planar reinforcement materials 21, general geotextiles or the like are used. After that, large sandbags 22 are piled up on the planar reinforcement materials 21 (FIG. 1(d)), and when they reach a predetermined height (FIG. 1(e)), the emergency work is completed. In this state, trains 31 on the embankment 10 can run.

[0017] After the emergency work is completed, the main restoration work is carried out. Figures 2 to 4 show the process sequence of the main restoration work. During the main restoration, the large sandbags 22 piled up in the emergency work are first removed in stages as shown in Figure 2. Figure 2(a) is a cross-sectional view of the embankment 10, and Figure 2(b) is a side view of the slope 11. In the example of Figure 2, the large sandbags 22 of the same height are removed at appropriate intervals from a high position, but each stage may be removed sequentially at appropriate intervals in the horizontal direction. In the portion where the planar reinforcement 21 is thus exposed, the rod-shaped reinforcement 23 is inserted from above the planar reinforcement 21 toward the slope 11 as shown in Figure 3. The rod-shaped reinforcement 23 is preferably one that can be driven into the slope 11 by hand, and for example, a deformed steel bar or a rock bolt is used. When the planar reinforcement 21 is in a mesh shape, the rod-shaped reinforcement 23 is inserted into the opening of the mesh. At this time, in order to prevent the entire rod-shaped reinforcing material 23 from becoming embedded in the mesh, it is preferable to provide an anchoring member 24 at the base end of the rod-shaped reinforcing material 23 and to anchor the anchoring member 24 to the surface of the planar reinforcing material 21.

[0018] 4(b), the rod-like reinforcement members 23 are preferably arranged alternately in the longitudinal direction of the embankment 10, for example in a staggered arrangement, on each step of the planar reinforcement member 21 laid in a stepped pattern, and are provided approximately evenly over the entire surface of the planar reinforcement member 21. The diameter, number, etc. of the rod-like reinforcement members 23 are designed so as to satisfy the strength required by the condition of the slope 11 and trains 31, etc., running on the embankment 10.

[0019] By laying the sheet reinforcement 21 on the back side of the large sandbags 22, the tension of the sheet reinforcement 21, the weight of the surrounding large sandbags 22, and the rod-shaped reinforcement 23 can ensure the stability of the slope 11 against the load of the train 31, even when the large sandbags 22 are being removed in stages. Therefore, the train 31 can operate even while the large sandbags 22 are being removed. Also, as shown in Figure 4, even when the restraint by the large sandbags 22 is no longer present, the tension of the sheet reinforcement 21 and the rod-shaped reinforcement 23 can sufficiently maintain the stability of the slope 11 with the load of the train 31 moving slowly.

[0020] After all the large sandbags 22 have been removed and rod-shaped reinforcement materials 23 have been inserted over the entire surface of the planar reinforcement material 21, as shown in Fig. 5, reinforced embankment is constructed on the planar reinforcement material 21 as a permanent restoration material 25, completing the permanent restoration work. When constructing the reinforced embankment, it is preferable to lay sheet-like embankment reinforcement materials 26 on each step of the stepped slope 11. It is also preferable to install drainage pipes 27 at appropriate intervals to drain water generated inside the embankment 10, including the permanent restoration material 25, to the outside of the embankment 10.

[0021] As described above, according to this embodiment, after the emergency work is completed, the main restoration work can be carried out without stopping the operation of trains, etc., and without performing large-scale temporary retaining work when removing the large sandbags. Therefore, the time for stopping the traffic of vehicles and trains running on the embankment can be minimized, and the slope 11 of the collapsed embankment 10 can be quickly restored. In addition, since the planar reinforcement material 21 is fixed to the slope 11 and pressed down by the main restoration material 25 on top of it, the earthquake resistance of the restored embankment can be improved. In addition, the main restoration material 25 protects the planar reinforcement material 21 from long-term ultraviolet rays, rainfall, etc., and enhances its durability.

[0022] In the present invention, the restoration material 25 is not limited to reinforced embankment. For example, as shown in Fig. 6, a cage frame 25a made of metal or reinforced fiber may be used as the restoration material and installed on the planar reinforcement material 21. Alternatively, the planar reinforcement material 21 may be covered with concrete.

[0023] Although the preferred embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention. [Industrial Applicability]

[0024] The present invention is useful as a method for restoring embankments whose slopes have collapsed due to large-scale natural disasters or the like. [Explanation of symbols]

[0025] 10 Embankment 11 Slope 21 Surface reinforcement material 22 Sandbags 23 Rod-shaped reinforcement material 24 Fixing member 25 restored pieces 26 Embankment reinforcement material 27 Drain pipe 31 Train

Claims

1. A construction method for restoring embankment where a slope has collapsed, comprising the steps of: After carrying out emergency repairs, the main restoration work was carried out. The emergency work is as follows: A step of shaping the collapsed slope into a staircase shape; A step of laying a planar reinforcement material along the shaped stepped surface; and placing a sandbag on the planar reinforcement material. The restoration work is as follows: removing the sandbag; A step of inserting a rod-shaped reinforcement material from above the planar reinforcement material at the position where the sandbag was removed toward the slope; Repeating the step of removing the sandbag and the step of inserting the rod-shaped reinforcement material in this order; A step of laying embankment reinforcement material on each step of the planar reinforcement material laid in a stepped manner after removing all of the sandbags; and a step of constructing a restoration material on top of the embankment reinforcement material.

2. 2. The method for carrying out embankment restoration work according to claim 1, characterized in that the main restoration work includes a step of installing a drainage pipe for draining water inside the embankment to the outside of the embankment.

3. 3. The method for carrying out embankment restoration work according to claim 1, wherein the surface reinforcement material is a geotextile.

4. 4. A method for constructing embankments for restoration work according to claim 1, wherein the rod-shaped reinforcement is a reinforcing bar having an anchoring portion for the planar reinforcement at its base end.

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