Structure and method for removing sediment from rockfall protection facilities

Abstract

To provide a structure and method for removing accumulated material from rockfall protection facilities such as rockfall protection fences F2, which can be guided more safely and reliably down the slope S, allowing for removal work to be carried out at the bottom of the slope. [Solution] A rockfall protection facility sediment removal structure 10 and sediment removal method are constructed using a cylindrical body 1 having numerous holes in its body, a fixing member that fixes the cylindrical body 1 to a slope S with one opening 2 of the cylindrical body 1 positioned directly below the rockfall protection fence F2 and another opening 3 positioned downwards on the slope, and a bottom cover 5 that can open and close the other opening 3 of the cylindrical body 1.

Description

Technical Field

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[0003]

[0001] The present invention relates to a sediment removal structure and a sediment removal method for removing sediments such as fallen rocks deposited on a rockfall protection facility such as a rockfall protection fence.

Background Art

[0002] Conventionally, as countermeasures against rockfalls on natural slopes such as mountainsides, various rockfall protection facilities such as rockfall protection fences, rockfall protection retaining walls, rockfall protection nets, rockfall protection sheds, and rock sheds are known. Among them, a rockfall protection fence composed of lightweight members such as columns, wire meshes, and ropes requires a smaller foundation than other protection facilities and is easy to install. Therefore, it is effective as a relatively small-scale rockfall countermeasure and has been adopted for many years on many rockfall slopes.

[0003] In addition, since the installation of a rockfall protection fence or a rockfall protection retaining wall is relatively easy, as shown in FIG. 6, for example, when a rockfall generation source A exists at a high position on a slope S, not only a rockfall protection fence F1 is provided at the lower part of the slope near a facility B such as a road to be protected, but also another rockfall protection fence F2 is provided in the middle part of the slope S, and a plurality of rockfall protection fences are installed in a multi-stage manner. In FIG. 6, what is indicated by the reference sign W is a rockfall protection retaining wall used in combination with the lower rockfall protection fence F1.

[0004] By the way, after the installation of these rockfall protection facilities such as rockfall protection fences, fallen rocks and the like accumulate. Therefore, in order to maintain the rockfall protection function, this sediment must be removed sooner or later. However, as shown in FIG. 6, the work of removing the sediment D2 of the rockfall protection fence F2 installed particularly in the middle part of the slope S is not only a work with poor scaffolding, but also, for example, when removing fallen rocks removed from the wire mesh or the like of the rockfall protection fence F2 and carrying them to another place, there is always a risk of falling again downward on the slope, and there is a difficulty that it has to be an extremely dangerous work.

[0005] To date, the following patent documents 1 and 2 are known as countermeasures against sediment accumulation in rockfall protection facilities. However, these countermeasures merely concern methods for removing sediment from the wire mesh of rockfall protection facilities, and do not disclose anything about the work involved in transporting the sediment removed from the wire mesh. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 52-18005 [Patent Document 2] Patent No. 6689700 [Overview of the project] [Problems that the invention aims to solve]

[0007] This invention was made in view of the above-mentioned difficulties in conventional measures against sediment accumulation in rockfall protection facilities, and aims to provide a sediment removal structure and method for rockfall protection facilities that can safely and reliably guide sediment downwards on the slope, even when the rockfall protection facility is installed in the middle of the slope, and carry out removal work at the bottom of the slope. [Means for solving the problem]

[0008] The present invention relates to a rockfall protection structure for removing deposits such as rocks that have accumulated on the rockfall protection facility, The structure comprises a cylindrical body having openings at both ends and numerous holes in its body, a fixing member for fixing the cylindrical body to a slope with one opening of the cylindrical body positioned directly below the rockfall protection facility and the other opening positioned below the slope, and a bottom cover for closing the other opening of the cylindrical body in an openable and closable manner. The rockfall protection facility is characterized by taking in the sediment accumulated on the rockfall protection facility through one of the openings of the cylindrical body, and guiding the taken-in sediment to the other opening while absorbing the kinetic energy of the falling sediment as it falls within the cylinder of the cylindrical body having the hole.

[0009] Furthermore, the present invention is characterized by providing a guide for guiding the sediment accumulated in the rockfall protection facility to the one opening of the cylindrical body.

[0010] Furthermore, the present invention is characterized in that the tubular body is made up of a mesh-like material having a large number of meshes.

[0011] Furthermore, the present invention relates to a method for removing deposits such as fallen rocks that have accumulated on a rockfall protection facility, A cylindrical body preparation step involves preparing a cylindrical body having openings at both ends, numerous holes in the body, and a bottom cover on one of the openings that can be opened and closed, A cylindrical body fixing step involves fixing the cylindrical body to a slope with one opening of the cylindrical body positioned directly below the rockfall protection facility and the other opening having the bottom cover positioned below the slope, The rockfall protection facility is characterized by comprising a deposit guidance step, in which the deposits accumulated on the rockfall protection facility are taken in through one opening of the cylindrical body, and the taken-in deposits are guided to the other opening by dropping them within the cylinder of the cylindrical body having the hole, while absorbing the kinetic energy of the falling deposits.

[0012] Furthermore, the present invention is characterized in that, after the sediment induction step, a sediment removal step is performed in which the bottom lid of the cylindrical body is opened and the sediment inside the cylindrical body is removed.

[0013] Furthermore, the present invention is characterized by performing a cylindrical body removal step in which the cylindrical body is removed from the slope after the cylindrical body removal step. [Effects of the Invention]

[0014] According to the sediment removal structure and sediment removal method for rockfall protection facilities of the present invention, since one opening of the cylindrical body is located directly below the rockfall protection facility where sediment removal work is to be carried out, the sediment removed from the rockfall protection facility can be reliably taken into the opening of the cylindrical body, and the sediment removal work can be carried out more safely and reliably. Furthermore, since one opening of the cylindrical body is located directly below the rockfall protection facility, it is not necessary to make the opening of the cylindrical body robust enough to withstand large rockfall impacts or to attach impact mitigation equipment, and the sediment removal structure can be easily constructed at low cost and sediment removal work can be carried out.

[0015] Furthermore, since the sediment taken in through one opening of the cylindrical body is allowed to fall inside the cylinder, its direction of fall can be controlled, and it can be reliably guided to a designated location on the slope where the other opening of the cylindrical body is located, and accumulated there. Therefore, the work of removing the sediment from inside the cylindrical body, and the work of transporting the removed sediment to another location, can be carried out more safely and easily.

[0016] Furthermore, because the cylindrical body has numerous holes, the kinetic energy of the falling sediment is gradually absorbed by collisions with the edges of each hole, guiding it to the other openings of the cylindrical body, where it can be safely and securely stopped by the bottom cover. Therefore, it is not necessary to make the other openings or the bottom cover of the cylindrical body robust enough to withstand large rockfall impacts, or to install impact mitigation equipment. This also allows for the construction of a low-cost and easy sediment removal structure and the carrying out of sediment removal work. [Brief explanation of the drawing]

[0017] [Figure 1] This is a partial perspective view of the cylindrical body used in the sediment removal structure of the rockfall protection facility in this embodiment. [Figure 2] This is a side view of the sediment removal structure of the rockfall protection facility according to this embodiment. [Figure 3] This is a bird's-eye view of the sediment removal structure of the rockfall protection facility according to this embodiment. [Figure 4]It is a side view showing a sediment induction process in the sediment removal method of the rockfall protection facility of the present embodiment. [Figure 5] It is a side view showing a sediment removal process inside the cylinder in the sediment removal method of the rockfall protection facility of the present embodiment. [Figure 6] It is a side view showing an example of a multi-stage installation of a conventional rockfall protection fence.

Mode for Carrying Out the Invention

[0018] As shown in FIGS. 1 to 3, the sediment removal structure 10 of the rockfall protection facility of the present embodiment includes a cylindrical body 1 having openings (2·3) at both ends, a fixing member 4 for fixing the cylindrical body 1 to a slope S such as a mountainside, a bottom cover 5 for closing the lower opening 3 of the cylindrical body 1 in an openable and closable manner, and a guide 6 for guiding sediment to the upper opening 2 of the cylindrical body 1.

[0019] As shown in FIG. 1, the cylindrical body 1 has an opening 2 and another opening 3 at both ends in its longitudinal direction, and has a number of hole portions 11·11… in its body portion. The cylindrical body 1 of the present embodiment is composed of a metal mesh body having a number of meshes, and has a long rectangular tube shape with an opening height of about 1 m × an opening width of about 1 m. Further, metal reinforcing frames 21·31 are provided at the opening edge portions of each of the one opening 2 and the other opening 3. In addition, as the material of the cylindrical body 1, in addition to a metal mesh body, for example, expanded metal, a mesh-shaped surface material formed by joining steel wire rods in a vertical and horizontal grid pattern, a synthetic resin mesh body, etc. can be appropriately adopted. Further, the cylindrical body 1 may be constituted by connecting a plurality of cylinders made of these various materials in series as required.

[0020] The fixing member 4 of the present embodiment is composed of a fastener 41 fixed to the outer surface of the cylindrical body 1 and a well-known anchor (not shown), and a plurality of fixing members 4 are provided at the reinforcing frames (21·31) and the body portion of the cylindrical body 1 at predetermined intervals from each other. In addition, a well-known wire rope may be used in combination as the fixing member 4.

[0021] The bottom cover 5 of this embodiment is made of a rectangular steel plate and is inserted from above into a pair of vertical grooves 51 provided in the reinforcing frame 31 of the other opening 3 of the cylindrical body 1. The bottom cover 5 closes the other opening 3 of the cylindrical body 1, and by sliding the bottom cover 5 up and down as needed, the other opening 3 can be opened to a desired degree. In addition to the steel plate, other materials such as a metal mesh, a synthetic resin mesh, expanded metal, or a mesh-like surface material made by joining steel wires in a vertical and horizontal grid pattern can be used as the material for the bottom cover 5. A known high-energy-absorbing mesh may also be used.

[0022] As shown in Figure 2, the guide 6 of this embodiment consists of a support column 61 fixed to the slope S and a mesh-like surface material 62 provided between the support column 61 and a reinforcing frame 21 of one opening 2 of the cylindrical body 1. This guide 6 is intended to guide accumulated rocks and other debris removed from the rockfall protection facility to one opening 2 of the cylindrical body 1 without receiving them, and is installed in a funnel shape. In addition to the mesh-like material, other materials such as expanded metal, a mesh-like surface material made by joining steel wires in a vertical and horizontal grid pattern, or a steel plate material without holes can be used as appropriate for the surface material 62 of the guide 6. Furthermore, a known high-energy-absorbing mesh-like material may be used.

[0023] The sediment removal structure 10 for the rockfall protection facility of this embodiment is constructed by fixing the cylindrical body 1 to the slope with a fixing member 4, with one opening 2 of the cylindrical body 1 positioned directly below the rockfall protection facility where the sediment removal work is to be carried out, and the other opening 3 positioned below the slope, and providing a guide 6 in the opening 2.

[0024] The following explanation of the method for removing deposits from a rockfall protection facility according to this embodiment will be given with reference to Figures 2 to 5, using the case of removing deposits D2 from a rockfall protection fence F2 that is already installed in the middle of a slope S as an example.

[0025] First, a cylindrical body preparation step is performed to prepare the cylindrical body 1, which has openings (2 and 3) at both ends, a number of holes 11 in its body, and a bottom cover 5 that closes one of the openings 3 so that it can be opened and closed. At this time, it is preferable to prepare multiple divided pieces of the required size that make up the cylindrical body 1, and various responses are possible depending on the site conditions.

[0026] Next, as shown in Figures 2 and 3, a cylindrical body fixing process is performed to fix the cylindrical body 1 to the slope S. That is, with one opening 2 of the cylindrical body 1 positioned directly below the rockfall protection fence F2 and the other opening 3 with the bottom cover 5 positioned lower down the slope, the cylindrical body 1 is placed on the slope S and fixed in place. At this time, it is preferable to remove any accumulated material (see accumulated material D1 in Figure 6) from the rockfall protection retaining wall W or rockfall protection retaining fence F1 that has been installed at the lower part of the slope S in advance, and various measures can be taken depending on the site conditions. Then, if necessary, a guide 6 is installed in one of the openings 2 of the cylindrical body 1.

[0027] Next, as shown in Figure 4, a deposit guidance process is performed in which the deposits D2 accumulated on the rockfall protection fence F2 are taken in through one opening 2 of the cylindrical body 1 and guided to the other opening 3. That is, the deposits D2 accumulated on the wire mesh of the rockfall protection fence F2 are gradually removed from the wire mesh by partially loosening or cutting it using conventional methods, and then guided by the guide 6 to be taken in through one opening 2 of the cylindrical body 1. Then, the deposits D2 such as rockfalls R taken in through one opening 2 are allowed to fall inside the cylindrical body 1 and guided to the other opening 3, which is provided with a bottom cover 5 at the bottom of the slope, and accumulated inside the cylinder. In this way, the deposits D2 accumulated on the rockfall protection fence F2 are removed. At the rockfall protection fence F2 from which the deposits D2 have been removed, restoration work such as replacing the wire mesh is carried out to prepare for future rockfalls.

[0028] After the above-described sediment induction process, if necessary, an internal sediment removal process is performed by opening the bottom lid 5 of the cylindrical body 1 and removing the sediment D3 inside the cylindrical body 1, as shown in Figure 5. This removal work can be carried out at another opening 3 located on the slope below, so it can be done relatively safely.

[0029] Following this process of removing sediment from inside the cylinder, a cylinder removal process is carried out as needed, in which the cylinder 1 and guide 6 are removed from the slope S. By removing the cylinder 1 and other components, the landscape of the site can be restored to almost the same state as when the rockfall protection fence F2 was installed.

[0030] As described above, according to the sediment removal structure 10 and sediment removal method for rockfall protection facilities of this embodiment, since one opening 2 of the cylindrical body 1 is located directly below the rockfall protection facility where the sediment removal work is to be carried out, the sediment removed from the rockfall protection facility can be reliably taken into the opening 2 of the cylindrical body 1, and the sediment removal work can be carried out more safely and reliably. Furthermore, since one opening 2 of the cylindrical body 1 is located directly below the rockfall protection facility, it is not necessary to make the opening 2 of the cylindrical body 1 or the guide 6 robust enough to withstand large rockfall impacts, or to attach impact mitigation equipment, and the sediment removal structure can be easily constructed at low cost and sediment removal work can be carried out.

[0031] Furthermore, since the sediment taken in through one opening 2 of the cylindrical body 1 is allowed to fall inside the cylindrical body 1, its direction of fall can be controlled, and it can be reliably guided to a predetermined location on the slope where the other opening 3 of the cylindrical body 1 is located, and accumulated there. Therefore, the process of removing the sediment D3 inside the cylindrical body 1, and the process of transporting the sediment removed from inside the cylindrical body 1 to another location, can be carried out more safely and easily.

[0032] Furthermore, since the cylindrical body 1 has numerous holes 11, falling rocks and other sediment can repeatedly collide with the edges of each hole 11 as they fall inside the cylindrical body 1. This gradually absorbs the kinetic energy of these sediments, guiding them to the other openings 3 of the cylindrical body 1, where they can be safely and securely stopped by the bottom cover 5. Therefore, it is not necessary to make the other openings 3 or the bottom cover 5 of the cylindrical body 1 robust enough to withstand large rockfall impacts, or to install impact mitigation equipment. This also allows for the construction of a sediment removal structure and the carrying out of sediment removal work at a low cost and with ease.

[0033] Furthermore, since the cylindrical body 1 has numerous holes 11, the condition inside the cylinder can be safely and easily observed from the outside of the cylindrical body 1 through each hole 11. In addition, rocks and other debris accumulated inside the cylinder can be safely drilled out from the outside of the cylindrical body 1 through each hole 11 using a rock drill or the like, making the removal of sediment inside the cylinder safer and easier.

[0034] Furthermore, since the cylindrical body 1 is composed of a mesh-like structure with numerous meshes, it is relatively lightweight and can be bent relatively easily in the longitudinal direction. Therefore, it offers a high degree of freedom in installation on slopes S, and as shown in Figure 3, for example, the cylindrical body 1 can be easily installed along ravines and valleys of slope S depending on the situation, resulting in excellent workability.

[0035] Furthermore, according to the sediment removal structure 10 and sediment removal method of the rockfall protection facility of this embodiment, the sediment D3 accumulated inside the cylindrical body 1 can be reliably held inside the cylinder. Therefore, if necessary, the slope S can be stabilized by accumulating the sediment D3 in part or all of the longitudinal direction of the cylindrical body 1 with the bottom cover 5 closed, without performing the sediment removal process inside the cylinder. In other words, the sediment removal structure 10 of this embodiment can also be used as a slope stabilization measure for the slope S, similar to well-known gabions, after the sediment D2 of the rockfall protection fence F2 has been removed. This slope stabilization by the cylindrical body 1 containing the sediment accumulated in the rockfall protection facility is particularly effective when rockfall accumulation areas have already formed along the ravines and valleys of the slope to be protected against rockfalls.

[0036] The sediment removal structure 10 and sediment removal method for the rockfall protection facility of this embodiment have been described above, but the present invention can also be implemented in other embodiments.

[0037] For example, in the above embodiment, one opening 2 of the cylindrical body 1 is located directly below the rockfall protection fence F2 installed in the middle of the slope S, and the other opening 3 is located at the bottom of the slope S. However, the present invention is by no means limited to this, and for example, one opening 2 of the cylindrical body 1 may be located directly below the rockfall protection fence installed at the top of the slope S. Furthermore, the other opening 3 of the cylindrical body 1 only needs to be located lower than the first opening 2, and may be located not only at the bottom of the slope S, but also in the middle of the slope, such as a gently sloping section of the slope.

[0038] Furthermore, in the above embodiment, the inner diameter and cross-sectional shape of the cylindrical body 1 are uniform along its entire length. However, for example, the diameter of one opening 2 and other openings 3 of the cylindrical body 1 may be made larger than that of the body, or the shape of the openings may be made different from that of the body. For example, instead of providing the guide 6, one opening 2 of the cylindrical body 1 may be formed in the shape of a funnel. Various design changes are possible depending on the accumulation of rocks on the rockfall protection fence, the slope conditions, etc.

[0039] Furthermore, although the above embodiment describes the removal of sediment in a rockfall protection fence as an example, it can also be applied to the removal of sediment in various rockfall protection facilities such as rockfall protection retaining walls, rockfall protection nets, rockfall protection shelves, and rock sheds.

[0040] Furthermore, although the above embodiment describes the removal of sediment accumulated on a pre-existing rockfall protection fence as an example, the present invention is by no means limited thereto. The sediment removal structure according to the present invention may be constructed simultaneously when installing various rockfall protection facilities, or the sediment removal structure according to the present invention may be constructed in the initial stages of sediment accumulation after the installation of rockfall protection facilities to prepare for future sediment removal work.

[0041] The present invention can also be implemented in various forms with improvements, modifications, and variations based on the knowledge of those skilled in the art, without departing from its spirit. Furthermore, the invention may be implemented in a form in which any of the inventive features is replaced with other technologies within the scope of producing the same function or effect, and an inventive feature that is configured as a single unit may be configured as multiple components, or an inventive feature that is configured as multiple components may be configured as a single unit. [Explanation of Symbols]

[0042] 10. Debris removal structure for rockfall protection facilities 1. Cylindrical body 11 Hole 2. One opening (of the cylindrical body) 3. Other openings (of the cylindrical body) 4 Fixing members 5 Bottom lid 6 Guide S slope F2 Rockfall protection fence (Rockfall protection facility) D2 (Accumulated deposits from rockfall protection fence) D3 (sediment inside the tubular body)

Claims

1. A rockfall protection facility deposit removal structure for removing rockfall deposits and other deposits accumulated on the facility, A cylindrical body having openings at both ends and numerous holes in its body, A fixing member for fixing the cylindrical body to a slope, with one opening of the cylindrical body positioned directly below the rockfall protection facility and the other opening positioned below the slope, A bottom cover that allows the other opening of the cylindrical body to be opened and closed, Equipped with, A rockfall protection structure for removing sediment accumulated on the rockfall protection facility, characterized in that sediment accumulated on the rockfall protection facility is taken in through one opening of the cylindrical body, and the taken-in sediment is guided to the other opening by dropping it inside the cylinder of the cylindrical body having the hole, while absorbing the kinetic energy of the falling sediment.

2. The rockfall protection structure for removing sediment accumulated in the rockfall protection facility, characterized in that it is provided with a guide for guiding the sediment accumulated in the rockfall protection facility to the one opening of the cylindrical body, as described in claim 1.

3. The sediment removal structure for a rockfall protection facility according to claim 1 or claim 2, characterized in that the cylindrical body is made of a mesh-like body having a large number of meshes.

4. A method for removing deposits such as rockfalls that have accumulated on rockfall protection facilities, A cylindrical body preparation step involves preparing a cylindrical body having openings at both ends, numerous holes in the body, and a bottom cover on one of the openings that can be opened and closed, A cylindrical body fixing step involves fixing the cylindrical body to a slope with one opening of the cylindrical body positioned directly below the rockfall protection facility and the other opening having the bottom cover positioned below the slope, A sediment guidance step is performed in which sediment accumulated in the rockfall protection facility is taken in through one opening of the cylindrical body, and the taken-in sediment is guided to the other opening by dropping it inside the cylinder of the cylindrical body having the hole, while absorbing the kinetic energy of the falling sediment. A method for removing sediment from a rockfall protection facility, characterized by having the following features.

5. After the aforementioned sediment induction process, A method for removing sediment from a rockfall protection facility according to claim 4, characterized in that a step is performed to remove sediment inside a cylindrical body by opening the bottom cover of the cylindrical body and removing the sediment inside the cylindrical body.

6. After the above-mentioned process of removing sediment from inside the cylinder, The method for removing deposits from a rockfall protection facility according to claim 5, characterized in that a cylindrical body removal step is performed to remove the cylindrical body from the slope.

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