Slope protection structure and method for constructing slope protection structure

Abstract

To provide slope protection structure capable of preventing soil and sand from flowing out from a slope to be treated and preventing weeds on the slope without using a thin and easily torn weed-proof sheet covering the slope, and a method for constructing the slope protection structure.SOLUTION: A bamboo chip installation is created by laying bamboo chips to a specified thickness on the ground of a slope to be treated. A soil stabilization frame is installed and fixed on the slope to be treated, and the bamboo chips are filled into each of multiple open cells in the soil stabilization frame, which then holds the bamboo chips in place and fixes them in place on the slope to be treated. This makes it possible to prevent soil erosion on the slope without using a thin, easily torn weed-proof sheet, and to prevent weeds on the slope and a germination and rooting of unwanted plants.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a slope protection structure for preventing soil and sand from flowing out from a slope and for controlling weeds on the slope, and a method for constructing the slope protection structure. [Background technology]

[0002] Various methods and structures have been proposed for preventing soil erosion from the ground on natural and artificial slopes, for weed control methods used to prevent weeds on the ground on natural and artificial slopes, and for soil erosion prevention structures and weed control structures constructed (produced) using these soil erosion prevention methods and weed control methods.

[0003] For example, the slope construction method in Patent Document 1 is proposed as a method that prevents soil from being washed away from the slope of the slope being constructed due to inflow water such as rainwater or spring water, and also prevents the unexpected germination of weeds and trees, thereby minimizing management work such as maintenance and inspection.

[0004] Here, according to this slope construction method, a sheet body is used in which a weed-control sheet and a surface drainage sheet are laminated and bonded together, and the surface drainage sheet of this sheet body is in close contact with the unevenness of the soil on the slope surface, and the soil on the slope is covered by the weed-control sheet, and the sheet body is laid on the soil that will become the topsoil of the slope. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2018-66159 Summary of the Invention [Problem to be solved by the invention]

[0006] Here, with the slope construction method described in Patent Document 1 and the slope structure produced thereby, the inorganic resin weed control sheet is left exposed on the surface of the slope, which gives the slope onto which the construction is carried out an inorganic appearance, and this presents a problem in that the landscape of the slope is marred.

[0007] Furthermore, the thickness of this weed control sheet is selected as appropriate within the scope of achieving the objective of exhibiting light blocking properties and water permeability to prevent plant seeds from taking root in the soil, but no special performance has been given to the sheet in terms of durability, etc., and it is considered to be of fairly ordinary durability.

[0008] For this reason, if such weed control sheets are left exposed to the atmosphere, they will naturally be susceptible to deterioration due to exposure to sunlight (especially ultraviolet and infrared rays), rainwater, melted snow, etc., and many of them will become damaged or prone to damage within roughly several years to around ten years.

[0009] The present invention has been made to solve the above-mentioned problems, and aims to provide a slope protection structure that can prevent soil and sand from flowing out from a slope and can implement weed control measures on the slope without using a thin, easily torn weed-control sheet to cover the slope, and a slope protection structure construction method for constructing the slope protection structure. [Means for solving the problem]

[0010] In order to achieve this purpose, the slope protection structure of the first invention is a structure for preventing soil erosion and weeds on slopes, and comprises a partition member that is laid and fixed on the slope to be worked on and stands upright on the ground of the slope to be worked on, a soil stabilization frame having a plurality of open cells divided by the partition member, and a bamboo chip laying body that is formed by assembling a plurality of stacks of bamboo chips filled into each of the plurality of open cells of the soil stabilization frame and is laid on the slope to be worked on.

[0011] The slope protection structure construction method of the second invention is a method for constructing a slope protection structure as described in claim 1, and includes a frame installation process of laying the soil stabilization frame on the slope to be constructed and arranging the plurality of open cells on the ground on the slope to be constructed, and a bamboo chip laying process of filling the plurality of open cells installed by the frame installation process with bamboo chips, gathering multiple stacks of bamboo chips on the slope to be constructed, and laying the bamboo chip laying bodies on the slope to be constructed.

[0012] According to the slope protection structure and slope protection structure construction method of the present invention, the bamboo chip laying body is formed by laying bamboo chips to a predetermined thickness on the ground of the slope to be constructed, and by installing and fixing a soil stabilization frame on the slope to be constructed and filling each of the multiple open cells provided in this soil stabilization frame with bamboo chips, the bamboo chips are held and fixed to the slope to be constructed.

[0013] With this bamboo chip installation, the multiple open cells in the soil stabilization frame are filled with a large number of bamboo chips in a stacked state, overlapping each other, so that the stack of bamboo chips filled in each open cell covers the ground of the slope to be worked on.By gathering multiple stacks of bamboo chips together, it is possible to prevent rainwater, melted snow, etc. from reaching the ground of the slope to be worked on, and it is also possible to prevent the rainwater and melted snow from seeping into the ground of the slope to loosen it and cause soil to flow out.

[0014] Furthermore, with the bamboo chip installation, the stack of bamboo chips filled into each open cell of the soil stabilization frame covers the ground of the slope to be worked on, thereby blocking sunlight from reaching the ground of the slope to be worked on, thereby preventing the seeds of unwanted plants such as weeds and trees from taking root in the ground of the slope to be worked on.

[0015] In particular, increasing the thickness of the bamboo chip laying body increases the distance that sunlight travels from the top surface of the bamboo chip laying body to the ground of the slope to be installed.As a result, as the thickness of the bamboo chip laying body increases, the amount of sunlight that reaches the ground of the slope to be installed decreases, making it possible to create an environment that makes it more difficult for plants to grow on the ground of the slope to be installed.

[0016] Furthermore, after the bamboo chip installation has been completed, if there is rain or snow due to natural weather changes, the bamboo chips will absorb water from the rain and the weight of the snow will increase the weight of each bamboo chip and compact the bamboo chips, further reducing the gaps between the bamboo chips.This will further reduce the amount of light, such as sunlight, that passes through the bamboo chip installation and reaches the ground on the slope where the installation is being carried out, making it even easier to create an environment where it is more difficult for plants to grow on the ground on the slope where the installation is being carried out.

[0017] Furthermore, unlike conventional resin weed control sheets, the slope to be treated is covered with a bamboo chip laying body in which naturally occurring bamboo chips are exposed on the surface, so the appearance of the slope to be treated does not become unnatural and inorganic compared to the surrounding natural landscape, and the appearance of the slope to be treated blends into the surrounding landscape, preventing it from becoming unnatural.

[0018] Furthermore, since the bamboo chip installation body is a collection of laminated layers of naturally occurring bamboo chips, it does not break or become easily broken due to deterioration, as does the conventional thin weed control sheet. [Effects of the Invention]

[0019] The slope protection structure and slope protection structure construction method of the present invention have the advantage of being able to prevent soil and sand from escaping from a slope without using a thin, easily torn weed-proof sheet to cover the slope to be constructed, as well as being able to control weeds on the slope and prevent unwanted plants from sprouting and taking root. [Brief explanation of the drawings]

[0020] [Figure 1] (a) is a front view (including a cross section along line IA-IA in (b)) showing a slope protection structure constructed using a slope protection structure construction method that is an embodiment of the present invention, and (b) is a longitudinal cross-sectional view of the slope protection structure along line IB-IB in (a). [Figure 2] (a) is a front view (including a cross section along line IIA-IIA in (b)) showing the state in which the soil stabilization frame has been installed and fixed on the slope to be worked on, and (b) is a longitudinal cross section along line IIB-IIB in (a). [Figure 3] (a) is a plan view of a soil stabilization frame used in a slope protection structure, (b) is a cross-sectional view of the soil stabilization frame taken along line IIIB-IIIB in (a), and (c) is a cross-sectional view of the soil stabilization frame taken along line IIIC-IIIC in (a). [Figure 4] 2(a) is a flowchart showing a slope protection structure construction method for constructing the slope protection structure shown in FIG. [Figure 5] 4(a) is a flowchart showing the unnecessary object removal process in the slope protection structure construction method of FIG. 4(a), and FIG. 4(b) is a flowchart showing the base treatment process in the slope protection structure construction method of FIG. 4(a). DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1(a) is a front view (including a cross section taken along line IA-IA in Figure 1(b)) of a slope protection structure 1 constructed by a slope protection structure construction method according to an embodiment of the present invention, and Figure 1(b) is a longitudinal cross section of the slope protection structure 1 taken along line IB-IB in Figure 1(a).

[0022] Figure 2(a) is a front view (including a cross section along line IIA-IIA in Figure 2(b)) showing the state in which the soil stabilization frame 2 has been installed and fixed on the slope 20 to be worked on, and Figure 2(b) is a longitudinal cross section along line IIB-IIB in Figure 2(a). Note that Figure 2 shows the state before bamboo chips 3a are filled into each open cell 2b of the soil stabilization frame 2, and the bamboo chips 3a and bamboo chip laying body 3 are not shown in this figure.

[0023] Figure 3(a) is a plan view of the soil stabilization frame 2 used in the slope protection structure 1, Figure 3(b) is a cross-sectional view of the soil stabilization frame 2 taken along line IIIB-IIIB in Figure 3(a), and Figure 3(c) is a cross-sectional view of the soil stabilization frame 2 taken along line IIIC-IIIC in Figure 3(a).

[0024] FIG. 4(a) is a flowchart showing a slope protection structure construction method for constructing the slope protection structure 1 shown in FIG.

[0025] Figure 5(a) is a flowchart showing the unnecessary object removal process S1 in the slope protection structure construction method of Figure 4(a), and Figure 5(b) is a flowchart showing the base preparation process S2 in the slope protection structure construction method of Figure 4(a).

[0026] <Slope protection structure> As shown in Figure 1, the slope protection structure 1 of this embodiment comprises a soil stabilization frame 2 laid on the ground 21 of the slope 20 to be worked on, and a bamboo chip laying body 3 laid on the ground 21 of the slope 20 to be worked on, held and fixed to a predetermined thickness (see Figure 1(b)) via this soil stabilization frame 2.

[0027] Here, the slope 20 to be constructed includes both artificial and natural slopes, where an artificial slope refers to a slope constructed using embankment, cut earth, or both, and a natural slope refers to a slope formed naturally without any artificial civil engineering work being carried out.

[0028] <Soil stabilization frame> The soil stabilization frame 2 is a frame body for holding and fixing bamboo chips 3a at a predetermined thickness on the ground surface 21 of the slope 20 to be worked on, in order to prevent the outflow of surface soil and sand on the ground surface 21 of the slope 20 to be worked on, and to provide weed control measures for the slope 20 to be worked on. Note that this soil stabilization frame 2 does not have a concrete frame body like a so-called concrete crest frame.

[0029] As shown in Figure 2(a), the soil stabilization frame 2 comprises a partition member 2a which forms the main body of the soil stabilization frame 2, and a plurality of open cells 2b which are partitioned by the partition member 2a. The soil stabilization frame 2 is an assembly of a plurality of open cells 2b which are adjacently grouped together, and each of the plurality of open cells 2b is separated by a partition member 2a, and the entire periphery of each open cell 2b is surrounded by the partition member 2a.

[0030] As shown in Figure 3(a), the multiple open cells 2b are formed in a honeycomb shape (including shapes similar to a honeycomb shape; the same applies below) consisting of multiple open cells 2b that are regular hexagonal in plan view. The honeycomb shape of this soil stabilization frame 2 is such that the multiple open cells 2b, separated by the partition members 2a, are all formed in the same size as regular hexagons in plan view, and these multiple open cells 2b are assembled in a mathematical "plane tessellation" state.

[0031] The planar shape of each open cell 2b in the soil stabilization frame 2 of the present invention is not necessarily limited to a regular hexagon in plan view. For example, the soil stabilization frame 2 is formed by assembling a plurality of open cells 2b in a planar state partitioned by partition members 2a, and as long as each open cell 2b penetrates from the top to the bottom of the partition member 2a and has a planar shape, it may be an array of a plurality of open cells 2b of the same size in the shape of an equilateral triangle, square, rhombus, or parallelogram, or it may be an array of a plurality of open cells 2b of the same size in the shape of a circle or other shape, even if it does not result in a mathematical plane filling.

[0032] As shown in Figure 3, the soil stabilization frame 2 has a partition member 2a formed from a flexible material such as a resin material, nonwoven fabric, or a composite material thereof, and is capable of expanding and contracting, for example, in the left-right direction of Figure 3(a).

[0033] Therefore, according to this soil stabilization frame 2, the partition member 2a can be deformed in both directions, from one to the other, between an expanded state (the state shown in Figure 3(a)) in which each open cell 2b expands until the inner surfaces on the left and right sides of each open cell 2b separate to form a regular hexagon in a planar view, as shown in Figure 3(a), or a contracted state in which each open cell 2b is crushed until the inner surfaces on the left and right sides of each open cell 2b approach each other and abut or nearly abut against each other.

[0034] In this way, according to the soil stabilization frame 2, its partition member 2a can be reversibly transformed from one of an expanded state or a contracted state to the other. Therefore, for example, when transporting it to the slope 20 to be worked on, the partition member 2a can be made easier to transport by being in a more compact contracted state than its expanded state. On the other hand, when transporting it to the slope 20 to be worked on and installing it there, the partition member 2a simply needs to be transformed from the contracted state to the expanded state and installed on the slope 20 to be worked on, so installation can be easily carried out without the need to reassemble the soil stabilization frame 2 on site at the slope 20 to be worked on.

[0035] As shown in Figures 3(b) and 3(c), the soil stabilization frame 2 has its partition members 2a formed as strips with a width greater than its thickness, for example, the width of these strips is approximately 5cm to 15cm. Therefore, when this soil stabilization frame 2 is installed on the slope 20 to be constructed as shown in Figures 1 and 2, the height of each open cell 2b (the height of the slope 20 to be constructed in the vertical direction relative to the ground 21) is approximately 5cm to 15cm, and by filling each open cell 2b with bamboo chips 3a, the bamboo chips 3a can be stacked and laid to a thickness of 5cm to 15cm.

[0036] In addition, this soil stabilization frame 2 may be made of a ready-made product for slope protection, such as a ground or slope reinforcement material formed by connecting resin-impregnated nonwoven fabric frame material for ground reinforcement or narrow sheet material made of high-density polyethylene resin in a honeycomb shape when viewed from above.

[0037] As shown in Figure 2(b), when the partition members 2a of the soil stabilization frame 2 are laid on the ground 21 of the slope 20, they are erected at a predetermined height from the ground 21 of the slope 20, and each of the multiple open cells 2b is a space that penetrates from the top to the bottom of the partition member 2a. The spaces between the multiple open cells 2b are filled with bamboo chips 3a.

[0038] <Fixing fixture> As shown in Figures 2(a) and 2(b), the multiple fixing devices 4 are rod-shaped bodies with pointed tips that make them easy to drive into the ground like bamboo stakes, wooden stakes, anchor pins, etc., and by hitting the heads with a driving tool and driving the tips into the ground 21, the tips are inserted into the ground of the slope 20 to be worked on.

[0039] These multiple fixing devices 4 are inserted into the multiple opening cells 2b that are located on the outermost periphery of all the opening cells 2b in the soil stabilization frame 2, and in this inserted state are inserted into the ground 21 of the slope 20 to be worked on.In this state, each fixing device 4 is engaged and fixed to the ground 21 of the slope 20 to be worked on, with the partition member 2a kept in an expanded state, so that the outer surface of the fixing device 4 abuts against the side of the partition member 2a of the soil stabilization frame 2 and the partition member 2a is hooked.

[0040] Here, most conventional weed control sheets are made of relatively thin fabric, which becomes brittle due to deterioration over time and is therefore prone to tearing. In particular, those that are fixed to slopes by having anchor pins inserted into them are prone to localized tearing at the points where the anchor pins are inserted, and if a large force, such as the force of a strong wind or other external force, acts on the points where the anchor pins are inserted, the tear will expand and the weed control sheet will be completely damaged.

[0041] In contrast, according to the soil stabilization frame 2 of this embodiment, the fixing devices 4 are not driven directly into the partition member 2a and then also into the ground 21 of the slope 20 to be worked on, but rather multiple fixing devices 4 are driven directly into the ground 21, and the expanded partition member 2a is hooked onto these multiple fixing devices 4 and engaged and fixed to the ground 21 of the slope 20 to be worked on, so that the soil stabilization frame 2 is not damaged by the driving of these fixing devices 4.

[0042] <Bamboo chip paving body> As shown in Figures 1(a) and 1(b), the bamboo chip laying body 3 is laid on the slope 20 to be constructed by filling all of the open cells 2b of the soil stabilization frame 2 with bamboo chips 3a. The bamboo chips 3a used in this bamboo chip laying body 3 are mainly produced by crushing bamboo culms (the part of the tree that corresponds to the trunk, hereinafter referred to as "bamboo culms") with leaves and branches removed using a crusher. There are no particular restrictions on the moisture content of these bamboo chips 3a, but they are preferably in a dry state, for example, with a moisture content of 30% or less (including a moisture content of 0%; the same applies below).

[0043] Furthermore, the bamboo chips 3a used in this bamboo chip installation 3, when filled into each open cell 2b of the soil stabilization frame 2, preferably have a mass per unit volume (also called "filling density") of 0.2 to 0.3 × 10 2 kg / m 3The size (length, area, volume, etc.) of the bamboo chip laying body 3 is set so that the bamboo chips 3a are packed into the plurality of open cells 2b of the soil stabilization frame 2 at a packing density of 0.2 to 0.3 × 10 2 kg / m 3 It is filled so that

[0044] <Slope protection structure construction method> Next, a slope protection structure construction method, which is a construction method for the above-mentioned slope protection structure 1, will be described with reference to Figures 4 and 5. This slope protection structure construction method is one embodiment of the present invention, and mainly comprises a first step, unnecessary object removal step S1 (see Figure 5(a)), a second step, base preparation step S2 (see Figure 5(b)), a third step, frame installation step S3, and a fourth step, bamboo chip laying step S4.

[0045] <Unwanted items removal process> As shown in Figure 4, the unwanted object removal process S1 is the first process of the slope protection structure construction method, and is a process of removing unwanted objects from the ground 21 of the slope 20 to be constructed.As shown in Figure 5(a), it mainly includes a weeding process S11, a tree removal process S12, an other object removal process S13, and a slope inspection process S14.

[0046] The three steps of the unnecessary object removal step S1, the weeding step S11, the tree removal step S12, and the other object removal step S13, are all steps that are selectively performed as appropriate depending on the condition of the slope 20. Therefore, there are cases where all three steps are not required, or where only one or more of these three steps are performed, or where all three steps are performed.

[0047] According to this unwanted material removal process S1, when laying the soil stabilization frame 2 on the ground 21 of the slope 20 to be worked on, unwanted materials such as weeds, trees, stones, rocks, garbage, dumped materials, and other unwanted materials (hereinafter collectively referred to as "unwanted materials") on the slope 20 to be worked on are removed from the slope 20 to the extent that they do not get in the way and hinder the stable installation of the soil stabilization frame 2.

[0048] <Weeding process> The weeding step S11 shown in Figure 5(a) is a step of weeding and removing weeds and other plants (excluding trees; hereinafter referred to as "weeds, etc.") when they grow on the slope 20 to be worked on. If there are no weeds growing on the slope 20 to be worked on, this step S11 is skipped and the process moves to the next tree removal step S12.

[0049] Here, according to this weeding process S11, when weeding weeds and the like growing on the slope 20 to be worked on, the height of the weeds and the like is cut short to the extent that the contractor can visually determine the shape of the ground surface of the slope 20 to be worked on, for example, the unevenness of the ground surface of the slope 20 to be worked on, the presence or absence of spring water on the slope 20 to be worked on, and the presence or absence of water flowing into the slope 20 to be worked on.

[0050] It should be noted that this weeding process S11 does not necessarily have to include cutting down the roots of weeds, etc. (also called "uprooting"; the same applies below), but if the rhizomes and roots of weeds get in the way when laying the soil stabilization frame 2 on the slope 20 to be worked on, it may include cutting down the roots.

[0051] <Tree removal process> The tree removal process S12 is a process in which, if there are trees growing on the slope 20 to be worked on, the trees are cut down and removed, and the stumps of the trees are cut down and removed (hereinafter referred to as "tree removal"). If there are no unnecessary trees on the slope 20 to be worked on, this process S12 is skipped and the process moves to the next object removal process S13.

[0052] <Other objects removal process> The other object removal step S13 is a step for removing stones, rocks, garbage, dumped materials, and other unwanted objects that have been dumped or otherwise left on the slope 20. If there are no other unwanted objects on the slope 20, this step S13 is skipped and the process moves to the next slope inspection step S14.

[0053] <Slope inspection process> The slope inspection step S14 is a step for inspecting the condition of the ground surface 21 of the slope 20 to be worked on, and determining whether or not the base preparation step S2 for the slope 20 to be worked on is necessary based on the results of this inspection.

[0054] According to this slope inspection process S14, a comprehensive inspection is carried out on the slope 20 to be worked on, including the unevenness of the ground 21, the presence or absence of spring water, the presence or absence of water flowing in from other places, and the presence or absence of other unwanted objects, to determine whether the soil stabilization frame 2 can be stably installed on the slope 20 to be worked on.

[0055] If, as a result of this slope inspection process S14, it is confirmed that the difference in elevation of the unevenness on the ground surface 21 of the slope 20 to be worked on exceeds the appropriate value, the leveling process S21 is carried out in the next base preparation process S2, and if spring water or a large amount of water flowing in from elsewhere is confirmed on the slope 20 to be worked on, the drainage treatment process S22 is carried out in the next base preparation process S2.

[0056] Here, the appropriate value for the height difference between the unevenness of the ground surface 21 of the slope 20 to be worked on is set according to the thickness of the bamboo chip laying body 3, and it is preferable that it be equal to or less than the thickness of the bamboo chip laying body 3. Therefore, for example, if the thickness of the bamboo chip laying body 3 is 5 cm, the appropriate value will be equal to or less than 5 cm; if the thickness of the bamboo chip laying body 3 is 10 cm, the appropriate value will be equal to or less than 10 cm; and if the thickness of the bamboo chip laying body 3 is 15 cm, the appropriate value will be equal to or less than 15 cm.

[0057] After the slope inspection step S14 is performed, the unnecessary object removal step S1 is completed and the process moves to the next surface preparation step S2.

[0058] <Surface preparation process> As shown in Figure 4, the base preparation process S2 is the second process of the slope protection structure construction method, and is a process of adjusting the ground surface 21 of the slope 20 to be constructed in order to stably install the soil stabilization frame 2 on the slope 20 to be constructed.As shown in Figure 5(b), it mainly comprises a ground leveling process S21 and a drainage treatment process S22.

[0059] The two steps of the ground preparation step S2, the leveling step S21 and the drainage treatment step S22, are steps that are selectively performed as appropriate depending on the condition of the slope 20. Therefore, there are cases where none of these two steps are required, or where only one of these two steps is performed, or where both of these two steps are performed.

[0060] <Land leveling process> The leveling step S21 shown in Figure 5(b) is a step for leveling the slope 20 to be worked on to reduce the unevenness of the ground surface 21 when it is determined in the slope inspection step S14 (see Figure 5(a)) that the unevenness of the slope 20 to be worked on is extremely large. If it is determined that this leveling step S21 is unnecessary, this step S21 is skipped and the process moves to the next wastewater treatment step S22.

[0061] In this leveling process S21, if the ground 21 of the slope 20 to be worked on has extremely large irregularities, the ground 21 of the slope 20 to be worked on is leveled using human power, construction machinery or other tools, and the height difference of the irregularities in the ground 21 is adjusted to the appropriate value.

[0062] According to this leveling process S21, the unevenness of the slope 20 to be worked on is reduced by leveling it, making it easier to install the soil stabilization frame 2 in a state where it is in contact with the ground 21 of the slope 20 to be worked on as a whole.As a result, it is possible to prevent the soil stabilization frame 2 from swinging up and down on the slope 20 to be worked on, the soil stabilization frame 2 from sliding off the slope 20 to be worked on, or the soil stabilization frame 2 from being washed away by running water that flows down the slope 20 to be worked on due to rainfall.

[0063] <Wastewater treatment process> The drainage treatment step S22 is a step in which, when spring water or a large amount of water flowing in from elsewhere is found on the slope 20 to be worked on during the slope inspection step S14 (see Figure 5(a)), drainage structures are constructed on the slope 20 to drain the spring water or the large amount of water flowing in from there. If it is determined that this drainage treatment step 22 is unnecessary, this step S22 is skipped, the base preparation step S2 is completed, and the process moves on to the next frame installation step S3.

[0064] In addition to water flowing in from outside the slope 20 to be worked on, the water flowing in from other locations includes rainwater resulting from precipitation on the slope 20 to be worked on or its adjacent areas, and meltwater resulting from snowfall or snow accumulation.

[0065] Here, the drainage structure constructed in the drainage treatment process S22 is a drainage facility using an underdrain drainage channel, an underdrain drainage layer, suction prevention material and other drainage components, and is constructed appropriately using such drainage components so that spring water and inflow water present on the slope 20 to be treated are drained out of the slope 20 to be treated.

[0066] The culvert drainage channel is a drainage channel in which hydrophobic material is buried in a trench excavated in the ground 21 of the slope 20 to be worked on or its boundary portion, and a suction pipe is installed so as to be buried in the hydrophobic material at the bottom of the trench. Water that flows into the trench passes through the hydrophobic material and flows into the suction pipe, and is then drained out of the slope 20 to be worked on through the suction pipe.

[0067] The suction pipe used in this underdrain is, for example, a perforated pipe with many small holes drilled through it from its outer surface to its inner surface, allowing water to flow into the suction pipe. The hydrophobic material separates the soil and the suction pipe and allows water to pass through, and is made of, for example, crushed stone, gravel, nonwoven fabric (including the same type of nonwoven fabric used in suction prevention materials), or shells.

[0068] The underdrain drainage layer is a drainage channel formed by flat drainage material laid on the slope 20 to be constructed. Here, the flat drainage material is composed of a film material, mesh material, nonwoven fabric, or other water-permeable material (hereinafter simply referred to as "water-permeable material") that blocks or obstructs the inflow of soil particles and has water permeability, and a drainage channel formed as a space within the water-permeable material that can collect and flow water. Note that flat drainage material is also sometimes called sheet-shaped drainage material or plate-shaped drainage material.

[0069] This plane drainage material is formed in the shape of a long strip that extends mainly in the direction of inclination of the slope 20 to be treated, and the above-mentioned drainage channels are formed inside it along the extension direction so that they communicate with each other. Therefore, by laying this plane drainage material on the ground 21 of the slope 20 to be treated along the direction of inclination of the slope 20 to be treated, the plane drainage material can function as an underdrain drainage layer on the slope 20 to be treated, and water inside the slope 20 to be treated can be absorbed inside the plane drainage material and drained out of the slope 20 to be treated through the drainage channels inside it.

[0070] The suction prevention material is made of a flat, water-permeable nonwoven fabric that inhibits or blocks the intrusion of soil and other particles. This suction prevention material is formed into a sheet or mat using, for example, synthetic fibers, natural fibers, or a combination of these fibers, and the continuous gaps between the fibers of the nonwoven fabric allow water to flow through the material. By laying this material on the slope 20 to be treated, water inside the slope 20 to be treated can be drained out of the slope 20 via the suction prevention material.

[0071] <Frame installation process> The frame installation step S3 shown in Figure 4 is a step for laying and fixing the soil stabilization frame 2 on the slope 20. After this frame installation step S3, the process moves to the next bamboo chip laying step S4.

[0072] In this frame installation process S3, the soil stabilization frame 2, which has been transported in a folded state, is unfolded into an expanded state on the ground 21 of the slope 20 to be constructed. When unfolding the soil stabilization frame 2, the partition members 2a of the soil stabilization frame 2 are unfolded so that the planar shape of each open cell 2b of the soil stabilization frame 2 becomes a regular hexagon or a shape close to this, which is the appropriate opening shape, as shown in Figures 1(a), 2(a) and 3(a), and the soil stabilization frame 2 as a whole becomes a honeycomb shape.

[0073] After the partition members 2a of the soil stabilization frame 2 are expanded to an expanded state, fixing devices 4 are inserted into each of the predetermined opening cells 2b in the soil stabilization frame 2 from above toward the ground 21 of the slope 20 to be worked on, while maintaining this expanded state, and these multiple fixing devices 4 are each driven into the ground 21 of the slope 20 to be worked on, thereby fixing the partition members 2a of the soil stabilization frame 2 to the slope 20 to be worked on while still in the expanded state.

[0074] By using these multiple fixing devices 4, the soil stabilization frame 2 is laid in a fixed state on the slope 20 to be worked on, with its partition members 2a engaged with the ground 21 of the slope 20 to be worked on at multiple points, while maintaining a honeycomb shape in which each of its multiple open cells 2b has an appropriate regular hexagonal opening shape.

[0075] <Bamboo chip laying process> The bamboo chip laying process S4 is a process in which bamboo chips 3a are filled into all open cells 2b of the soil stabilization frame 2 laid on the slope 20 to be worked on, and the bamboo chips 3a are laid on the ground 21 of the slope 20 to be worked on to a predetermined thickness, i.e., the thickness of the soil stabilization frame 2 (height of the open cells 2b), thereby constructing the bamboo chip laying body 3 as if it were laid on the slope 20 to be worked on.

[0076] Here, in the frame installation process S3, the lower end of the partition member 2a of the soil stabilization frame 2 is grounded (abutted) against the ground surface 21 of the slope 20 to be worked on, and the partition member 2a is erected upright from the slope 20 to be worked on (see Figures 1(a) and 2(a)).In the bamboo chip laying process S4, bamboo chips 3a are filled into each open cell 2b of the soil stabilization frame 2 laid on the slope 20 to be worked on.

[0077] In this way, the bamboo chips 3a filled into each open cell 2b are filled from the lower end of the partition member 2a of the soil stabilization frame 2, i.e., from the ground surface 21 of the slope 20 to the upper end of the partition member 2a, so that the thickness of the bamboo chips 3a filled into each open cell 2b is stacked to a thickness roughly equal to the height of the partition member 2a.

[0078] In this way, the soil stabilization frame 2 stably holds the bamboo chips 3a filled in each open cell 2b on the slope 20 to be worked on and fixes them in that position.When bamboo chips 3a are filled into all of the open cells 2b of the soil stabilization frame 2, multiple stacks of bamboo chips 3a with a thickness corresponding to the height of the partition members 2a of the soil stabilization frame 2 are gathered together to form a bamboo chip laying body 3, and this bamboo chip laying body 3 is laid on the ground 21 of the slope 20 to be worked on.

[0079] This bamboo chip laying body 3 is formed by a stack of bamboo chips 3a filled into each open cell 2b of the soil stabilization frame 2 and assembled in a flat plane.As the thickness of the stack of bamboo chips 3a in each open cell 2b, i.e., the thickness of the bamboo chip laying body 3, increases, the rate of shading of sunlight reaching the ground 21 of the slope 20 to be treated tends to increase, thereby reducing the germination rate from the ground 21 of the slope 20 to be treated and improving the weed prevention effect.

[0080] Furthermore, since the bamboo chip installation body 3 remains filled in each open cell 2b of the soil stabilization frame 2, it is naturally exposed to rainwater, melted snow, etc. Therefore, after the bamboo chip 3a stack is formed, the bamboo chips 3a used in it may swell when wet with rainwater, melted snow, etc. However, as the bamboo chips 3a swell in this way, the gaps between the bamboo chips 3a decrease, further improving the shading rate against sunlight, etc., and as a result, the weed prevention effect can be improved.

[0081] In this bamboo chip laying process S4, bamboo chips 3a are filled into all open cells 2b of the soil stabilization frame 2 to form a layered body of bamboo chips 3a of a predetermined thickness. This concludes that the formation of the bamboo chip laying body 3 has been completed for the area in which the soil stabilization frame 2 is laid, and the bamboo chip laying process S4 is terminated, ending the slope protection structure construction method.

[0082] However, if the installation of the bamboo chip laying body 3 has not been completed in the entire construction range of the slope 20 to be constructed, the process will proceed to one of steps S1 to S3 (including steps S11 to S14 of step S1 and steps S21 to S22 of step S2) for the remaining construction range of the slope 20 to be constructed, depending on the progress of construction, and then the process up to step S4 will be carried out again, repeating the necessary processes until steps S1 to S4 have been completed for the entire construction range, after which this slope protection structure construction method will be terminated.

[0083] <Bamboo chip processing process> The bamboo chip processing step S5 is an auxiliary step for producing the bamboo chips 3a used in the bamboo chip laying step S4, and its main purpose is to adjust the size and moisture content of the bamboo chips 3a. By adjusting and reducing the moisture content of the bamboo chips 3a in this way, it is possible to prevent the bamboo chips 3a from swelling and causing volume expansion, and to more appropriately fill each open cell 2b of the soil stabilization frame 2 with more bamboo chips 3a.

[0084] According to this bamboo chip processing process S5, branches and leaves are removed from felled bamboo to produce bamboo culms, which are then split lengthwise along their axis to produce bamboo stalks. These stalks are then naturally or force-dried to reduce their moisture content to 30% or less (including 0% moisture content), and the stalks are then crushed into chips using crushing equipment such as a crusher to produce bamboo chips 3a.

[0085] Here, when bamboo culms are dried and then crushed using equipment such as a crusher, there is a risk that a large amount of moisture will remain in the spaces between the nodes of the bamboo culms and within the bamboo fibers.This residual moisture can delay the drying of the bamboo culms or increase the moisture content of the bamboo chips 3a after the bamboo culms are crushed, making it difficult to adjust the drying state of the bamboo chips 3a.

[0086] In contrast, if the bamboo culms are dried in the form of bamboo stalks and then crushed using equipment such as a crusher, the spaces between the nodes of the culms are destroyed when the culms are in the form of bamboo stalks, allowing the moisture contained therein to be expelled, and the moisture in the bamboo fibers also becomes easier to evaporate from the broken surfaces of the stalks, making it easier to adjust the moisture content of the bamboo chips 3a.

[0087] In addition, when crushing the bamboo chips 3a, the bamboo chips 3a are packed into each open cell 2b of the soil stabilization frame 2, and the mass per unit volume (also called "packing density") is preferably 0.2 to 0.3 × 10 2 kg / m 3 The size (length, area, volume, etc.) is adjusted so that

[0088] The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment, and it can be easily inferred that various improvements and modifications are possible within the scope of the present invention. [Explanation of symbols]

[0089] 1 Slope protection structure 2. Soil Stabilization Frame 2a Bulkhead member 2b Open cell 3 Bamboo chip laying body 3a Bamboo chips 4 Fixtures S1 Unwanted material removal process S2 Surface preparation process S3 Frame installation process S4 Bamboo chip laying process S5 Bamboo chip processing process S11 Weeding process S12 Tree removal process S13 Other object removal process S14 Slope inspection process S21 Land leveling process S22 Wastewater treatment process

Claims

1. In a slope protection structure for preventing soil erosion and weeds on a slope, a soil stabilization frame having partition members that are laid and fixed on the slope to be worked on and stand on the ground of the slope to be worked on, and a plurality of open cells that are partitioned by the partition members; A slope protection structure characterized by comprising a bamboo chip laying body formed by assembling multiple stacks of bamboo chips filled into each of the multiple open cells in the soil stabilization frame, and which is laid on the slope to be protected.

2. 2. A method for constructing a slope protection structure according to claim 1, comprising: a frame installation step of laying the soil stabilization frame on the slope to be constructed and arranging the plurality of open cells on the ground of the slope to be constructed; This slope protection structure construction method is characterized by including a bamboo chip laying process in which bamboo chips are filled into the multiple open cells installed by the frame installation process, multiple stacks of bamboo chips are assembled on the slope to be constructed, and the bamboo chip laying bodies are laid on the slope to be constructed.

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