JP2020117983A - Slope protection structure and slope protection method - Google Patents

Abstract

To provide a slope protection structure and a slope protection method that can effectively protect slopes by improving the slope protection capability of a slope frame and that is superior in durability.SOLUTION: A slope frame 12 for stabilizing a slope is installed in a protection structure 10 for a slope. The protection structure 10 comprises: a plurality of anchors 14 that are driven at intervals in a region where the slope frame 12 does not exist within an installation range of the slope frame 12; a net body 20 that is placed on the slope from above the slope frame 12 and that is made of a rhombic metal net; and a plate material 30 that is attached to heads of anchors 14 and that pushes the net body 20 down to a position lower than the top surface of the slope frame 12 and gives tension to the net body 20. Linear members that compose the net body 20 are ones that are made from hard steel wires as a raw material. The surface of the linear members has a zinc plating layer or a zinc aluminum alloy plating layer for which the coating amount is 80 g/mor more.SELECTED DRAWING: Figure 2

Description

The present invention relates to a slope protection structure and a slope protection method, and more particularly to a slope protection structure and a protection method in which a frame for stabilizing the slope is installed.

Conventionally, various slope protection technologies have been developed and put to practical use in order to prevent slope failures and sediment failures of natural grounds.

As a construction method for slope protection, a grid-shaped formwork is installed on the slope, and the on-site casting method for placing concrete in this formwork and the dismantling work of the formwork are unnecessary. The frame method is often adopted in which mortar or concrete is sprayed onto the formwork installed on the slope to fill up the formwork.

Further, as shown in FIGS. 15(A) and 15(B), a method frame construction method in which a lattice-shaped method frame 12 and an anchor 13 are combined is also constructed. In this method frame method, the anchor 13 whose tip reaches the stable formation G is placed at the intersection of the lattice method frames.

However, as shown in FIG. 15(A), if weathering or cracking of the legal framework 12 progresses over time and deteriorates, it is feared that the proof stress at the time of design cannot be maintained and the proof stress may be insufficient.

In order to eliminate the lack of strength of the legal framework, it is possible to remove the existing legal framework and establish a new legal framework, but this requires a huge amount of work time, labor, and cost. Therefore, there is a demand for a method that can additionally protect the slope without removing the legal framework.

As a protection work that can eliminate the lack of yield strength of the legal frame without removing the existing legal frame, for example, in Patent Document 1 in the region of the slope where the lattice-shaped frame member forming the legal frame is not arranged, A method of providing the described pressure receiving plate is conceivable.

The pressure receiving plate described in Patent Document 1 is a plate material made of cast iron, is fixed to a head of an anchor extending from an unstable layer G2 forming a surface layer of a slope to a stable formation G1 in the ground, and the slope is viewed from above. Press. The pressure receiving plate can be installed in each frame of the grid-shaped method frame.

JP, 11-158877, A

However, the protective work described in Patent Document 1 has a structure in which a newly driven anchor and a pressure receiving plate fixed to the head of the protective work are used to reinforce the existing legal frame itself. It was required to develop a slope protection structure that has excellent durability while improving slope protection performance by the legal framework.

The present invention has been made in view of the above problems, and with respect to a slope where a legal frame is installed, the slope protection performance by the legal frame can be enhanced to effectively protect the slope, and the durability is excellent. It is intended to provide a slope protection structure and a slope protection method.

In order to achieve the above object, the slope protection structure according to claim 1 is
In the protection structure of the slope where the law frame for slope stabilization was installed,
A plurality of anchors placed at intervals in the non-existing region of the law frame within the installation range of the law frame,
A net body made of a rhombus wire net laid on the slope from above the method frame,
A plate member that is attached to the head of the anchor and presses the net body to a position lower than the height position of the top surface of the method frame to apply tension to the net body;
The wire material forming the net body is a wire material made of a hard steel wire material, and has a zinc plating layer or a zinc aluminum alloy plating layer having an adhesion amount of 80 g/m ² or more on the surface. Characterize.

According to this configuration, the net body is laid on the slope from above the slope, and is pushed down to a position lower than the height position of the top face of the slope by the plate material fixed to the head of the anchor. The slope is in a state of being pressed by the net body through the law frame. As a result, the slope protection performance by the slope is improved, and slope collapse can be prevented by pressing the area of the slope where the slope is not located from above with a net, and the slope can be effectively protected. it can.

In addition, since the rhombus wire mesh that constitutes the net is made of a wire material made of hard steel wire, it is less likely to be plastically deformed as compared with an iron wire made of a commercially available mild steel wire, and has high tensile strength and spring properties. Have. In addition, by forming a zinc plating layer or a zinc aluminum alloy plating layer on the surface of the net and setting the amount of adhesion to 80 g/m ² or more, the net is laid from above the method frame, Even under the condition of rubbing against the frame, it is possible to maintain the anticorrosion performance of the net body and provide a structure having excellent durability.

The slope protection structure according to claim 2 is the slope protection structure according to claim 1, wherein
A cylindrical spacer disposed between the plate member and the slope and surrounding the outer periphery of the anchor,
The inside of the spacer is filled with a grout material.

According to this configuration, the spacer can make an appropriate difference between the height position of the top surface of the method frame and the height position of the net body pushed down by the plate material. Further, by filling the inside of the spacer with grout material, it is possible to prevent rust from being generated on the head of the anchor protruding from the slope, and to improve corrosion resistance.

The slope protection structure according to claim 3 is the slope protection structure according to claim 1 or 2, wherein
A cushioning body for abrasion resistance is provided between the plate material and the mesh body.

According to this configuration, it is possible to prevent the mesh body and the plate material from rubbing against each other and generating rust on the surface of the mesh body or the plate material by the cushioning body, so that the corrosion resistance can be further enhanced.

The slope protection structure according to claim 4 is the slope protection structure according to any one of claims 1 to 3.
The linear material forming the mesh has a diameter of ² to 5 mm and a tensile strength of 800 to 2000 N/mm ² , and the linear material according to claim 1. Slope protection structure.

According to this structure, since the net body is composed of the linear material manufactured from the hard steel wire rod having the tensile strength of 800 to 2000 N/mm ² , the net body is hard to be plastically deformed, and the high tensile strength and It can exhibit springiness. As a result, not only the slope surface portion, but also a surface slip having a depth of 1 m to 3 m from the slope surface can be prevented.

The slope protection method according to claim 5 is
In the method of protecting slopes where a legal framework for slope stabilization has been installed,
An anchor placing step of placing a plurality of anchors at intervals in the non-existing region of the law frame within the installation range of the law frame,
A net body laying step of laying a net body made of a rhombus wire net on the slope from above the method frame,
A plate member setting step of fixing the plate member to the anchor in a state where the net member is pushed down to a position lower than the top surface height position of the method frame by a plate member having a diameter larger than the mesh of the net member; Including,
The wire material forming the net body is a wire material made of a hard steel wire material, and has a zinc plating layer or a zinc aluminum alloy plating layer having an adhesion amount of 80 g/m ² or more on the surface. Characterize.

According to this configuration, the net body is laid on the slope from above the slope, and is pushed down to a position lower than the height position of the top face of the slope by the plate material fixed to the head of the anchor. The slope is in a state of being pressed by the net body through the law frame. As a result, the slope protection performance by the slope is improved, and slope collapse can be prevented by pressing the area of the slope where the slope is not located from above with a net, and the slope can be effectively protected. it can. Further, even when the net body is laid on the method frame and the mesh body and the method frame are rubbed with each other, the anticorrosive performance of the net body can be maintained and the structure can be excellent in durability.

The slope protection method according to claim 6 is the slope protection method according to claim 5,
After the plate material installation step, a greening base material injection step of injecting a greening base material between the slope and the net body is included.

According to this configuration, the greening base material injected between the slope and the net can green the non-installation area of the legal frame, which allows the slope surface to be exposed to the weather. Can be suppressed.

According to the slope protection structure and the slope protection method of the present invention, by laying a net on the slope on which the slope is installed, the slope protection performance by the slope is increased and the slope is improved. Not only can it be effectively protected, but the net body also has high anticorrosion performance and excellent durability.

The top view which shows typically one Embodiment of the protection structure of the slope which concerns on this invention. Sectional drawing which follows the II-II line of the protection structure of the slope shown in FIG. (A) is a plan view of the net, (B) is a side view of the net. The enlarged view of the X section of FIG. The perspective view of a spacer. (A)-(C) is sectional drawing which shows the modification of a spacer. (A) is a perspective view of the plate material viewed from the upper surface side, (B) is a perspective view of the plate material viewed from the lower surface side, and (C) is a side view of the plate material. 2. The YY sectional view taken on the line of FIG. Explanatory drawing of the anchor placement process of the protection method of a slope. Explanatory drawing of the net laying process of the protection method of a slope. Sectional drawing which shows the modification of the protection structure of a slope. (A) is sectional drawing which shows other embodiment of the slope protection structure which concerns on this invention, (B) is a top view of a bag. Sectional drawing which shows other embodiment of the protection structure of the slope which concerns on this invention. The top view which shows typically other embodiment of the protection structure of the slope which concerns on this invention. 7A is a perspective view of a slope on which a method frame that has deteriorated over time is installed, and FIG. 7B is a cross-sectional view of FIG.

FIG. 1 is a plan view schematically showing an embodiment of a slope protection structure according to the present invention, and FIG. 2 is a sectional view taken along line II-II of the slope protection structure shown in FIG. In addition, in FIG. 2, in order to explain the state of the anchor 13 that fixes the legal frame 12, a side view of the anchor 13 installed at the intersection of the legal frame 12 is shown by a solid line. The slope protection structure 10 (hereinafter, also simply referred to as "protection structure 10") is applied to the slope where the legal frame 12 is installed, and it is possible to reinforce the lack of durability of the existing legal frame 12.

The protection structure 10 includes a legal frame 12 installed on the slope S, a net 20 installed on the legal frame 12, an anchor 14 for fixing the net 20 to the slope S, an underlay material 16, The plate member 30, the spacer 40, and the cap nut 50 are provided. The underlay material 16, the plate material 30, the spacer 40, and the cap nut 50 are attached to the head of the anchor 14.

As the slope S to which the protection structure 10 is applied, for example, a slope formed by cutting the natural ground can be cited. As shown in FIG. 2, for example, the slope S has an unstable layer G2 (surface layer) of 1 m to 3 m that is easily weathered, and a stable ground layer G1 (deep layer) that is a stable ground therebelow. On this slope S, a lattice-shaped frame 12 is provided.

As shown in FIG. 1, the method frame 12 includes a plurality of vertical frame members 12a extending in the vertical direction (vertical direction of the slope S) with respect to the slope S and in the horizontal direction (direction substantially orthogonal to the vertical direction). It is a structure for stabilizing the slope, which has a plurality of lateral frame members 12b extending and is formed in a lattice shape by these. In the illustrated example, the intersecting frame members 12a and 12b extend in the vertical and horizontal directions, but the vertical and horizontal directions are such that the minimum unit frame shape is a rhombus when viewed from the lower side of the slope. It may be inclined and extended with respect to.

The legal frame 12 has a substantially rectangular cross section (generally trapezoidal cross section in the illustrated example) and has a substantially planar top surface 12c, which penetrates the legal frame 12 or has a head embedded in the legal frame 12. It is fixed to the stable formation G1 by anchors 13 such as rock bolts and ground anchors. In the present embodiment, anchors 13 are formed at the intersections of the grid-shaped frame 12 respectively. The distance between the adjacent anchors 13 can be set to 1 m to 3.5 m, for example. The cross-sectional shape of the legal frame 12 is not limited to a quadrangle, and various shapes such as a semicircular shape can be adopted. The size of the cross-sectional shape of the method frame 2 is, for example, a width w of 150 mm to 400 mm, preferably 150 mm to 300 mm, and a height h of 150 mm to 500 mm, preferably 150 mm to 350 mm.

The net 20 is laid on the legal frame 12 so as to cover the entire surface of the legal frame 12, and is fixed to the slope S by the anchor 14 and the plate member 30. As shown in FIG. 3(A), the mesh body 20 of the present embodiment is a diamond-shaped wire mesh having a diamond-shaped mesh 22. The size of the mesh of the mesh 20 is, for example, a diagonal length of one (shorter in the mesh of FIG. 3A) of 50 to 150 mm and a diagonal length of the other (longer in the mesh of FIG. 3A). Can be 50 to 200 mm.

In the present embodiment, the net body 20 is formed by weaving a metal linear member 24. The linear member 24 is manufactured from a hard steel wire having a diameter of 2mm~5mm size, preferably a size of diameter 3 mm to 4 ^mm, the tensile strength of 800N / mm ² ~2000N / mm 2 Have. As such a linear material, for example, a linear material produced from a hard steel wire defined in JIS G 3506, such as a galvanized steel wire (JIS G 3548), can be used. A wire rod made of a hard steel wire rod is a wire rod made of a mild steel wire rod defined in JIS G 3505, that is, an iron wire made of a commercially available mild steel wire (generally, with a tensile strength of 290 to 540 N/mm ²⁾ . It is less likely to be plastically deformed, and has high tensile strength and spring properties as compared with a general-purpose wire mesh made of

The wire material forming the net 20 is not limited to a metal material, and for example, a wire material formed of carbon fiber, glass fiber, aramid fiber or the like, or a resin wire material having high anticorrosion property may be used. it can. Further, the thickness d of the net body 20 shown in FIG. 3(B) is preferably 3 times or more the diameter of the linear member 24, and can be, for example, 10 mm to 30 mm.

The net body 20 further has a zinc plating layer or a zinc aluminum alloy plating layer having an adhesion amount of 80 g/m ² or more on the surface. If the plating layer is a galvanized layer, the deposition amount is preferably from 100 to 500 g / ^{m 2,} and more preferably 200 to 400 g / ^{m 2.} Further, if the plating layer is a zinc aluminum alloy plating layer, the deposition amount is preferably from 100 to 300 g / ^{m 2,} and more preferably 200-30Og / ^{m 2.} Further, the thickness of the plating layer is preferably 14 to 70 μm in the case of the zinc plating layer, more preferably 28 to 42 μm, and is preferably 10 to 50 μm in the case of the zinc aluminum alloy plating layer. , 30 to 48 μm is more preferable. When the plating layer is a zinc aluminum alloy plating layer, the zinc content is preferably 85% by mass to 95% by mass, and the aluminum content is preferably 5% by mass to 15% by mass.

Further, the linear member 24 forming the net body 20 may be coated with a synthetic resin on the surface of the zinc plating layer or the zinc aluminum alloy plating layer, and for example, saturated polyester (PET) or polyvinyl chloride (PVC). You may have the coating layer by these. Thereby, the corrosion resistance of the net 20 can be further enhanced.

The net body 20 is pressed in a direction approaching the slope S by the plate member 30 fixed to the head of the anchor 14. As shown in FIG. 4, the underlayment material 16, the spacer 40, the plate material 30, and the cap nut 50 are attached to the head of the anchor 14 in order from the slope S side toward the tip of the head.

As the anchor 14, a rock bolt or a ground anchor used in the ground anchor construction method can be used. The anchor 14 is located in the installation range of the legal frame 12 and in the non-existing region of the legal frame 12 (that is, the region of the slope S in the rectangular frame surrounded by the vertical frame member 12a and the horizontal frame member 12b). Thus, a plurality of slopes S are laid out at intervals and extend from the ground surface to the stable formation G1.

The underlay material 16 is a plate-like member and has a through hole formed in the center thereof. As the underlay material 16, for example, a steel plate whose front and back surfaces are subjected to anticorrosion treatment, a steel plate whose front and back surfaces are covered with FRP layers, or a resin plate in which a reinforcing material is embedded can be used. As shown in FIG. 4, the underlayment material 16 is arranged so that one surface of the underlayment material 16 contacts the slope S in a state where the head of the anchor 14 is inserted into the through hole.

The spacer 40 is a member that is disposed between the slope S and the plate member 30 and adjusts the height of separation of the net 20 from the slope S. In the present embodiment, as shown in FIGS. 4 and 5. It is arranged between the underlayment material 16 and the plate material 30 arranged on the slope S, and is formed in a cylindrical shape (a cylindrical shape in the present embodiment) surrounding the outer periphery of the anchor 14. In the present embodiment, part of the spacer 40 is embedded in the ground.

The spacer 40 according to the present embodiment includes a tubular main body 42, a flange 44 that projects radially outward from the outer peripheral surface of the main body 42, and one end of the main body 42 (hereinafter referred to as the upper end 42a). ) And the groove part 46 formed in. The spacer 40 can be formed of a resin material such as polyvinyl chloride (PVC) or polyethylene (PE) or a metal material. The height of the spacer 40 (that is, the length of the main body 42 in the cylinder axis direction) can be set to, for example, 15 mm to 50 mm. The outer diameter of the main body portion 42 is smaller than the diameter of the through hole of the underlayment material 16 and larger than the through hole 34 of the plate material 3 described later, and the outer diameter of the flange portion 44 is equal to that of the underlayment material 16. It is formed larger than the diameter of the through hole. The depth and width of the groove portion 46 are formed to a size that allows the linear member 24 constituting the net body 20 to be fitted into the groove portion 46.

In the installed state, the spacer 40 has the end portion (hereinafter, referred to as the lower end portion 42b) of the main body portion 42 where the anchor 14 penetrates through the main body portion 42 and does not have the groove portion 46 of the main body portion 42 is a through hole of the underlay material 16. And is embedded in the ground, and is arranged so that the upper end portion 42a side of the main body portion 42 projects from the slope S together with the flange portion 44. Further, in the present embodiment, the inside of the spacer 40 is filled with the grout material 18 such as cement milk or mortar.

The spacer 40 may be arranged between the slope S and the plate member 30 and can adjust the height of the net 20 from the slope S, for example, as shown in FIG. As shown in (B), the underlayment material 16 may not be provided. In such a case, it is preferable to embed one end of the spacer 40 in the ground. As another form, as shown in FIG. 6C, it has a tubular shape having no groove portion 46 or flange portion 44, and the outer diameter of the main body portion 42 is larger than the through hole of the underlayment 16. Alternatively, it may be arranged so as to be sandwiched between the underlayment material 16 and the plate material 30. In each embodiment, the length of the spacer 40 in the cylinder axis direction can be appropriately set in consideration of the length of the portion protruding from the slope S and the length of the portion buried in the ground. 40 has a protective coating for abrasion resistance that prevents abrasion of the surface of the net body 20 at least in a portion that can come into contact with the net body 20 in the installed state (for example, the upper end portion 42a side of the main body portion 42). You may have. This protective film can be formed of, for example, a rubber material or a resin material.

As shown in FIGS. 7A to 7C, the plate member 30 is a plate member having a through hole 34 formed in the center thereof, into which the anchor 14 is inserted, and is, for example, a resin in which a steel plate or a reinforcing member is embedded. It can be formed by a plate or the like. The plate material 30 is formed such that the major axis length (length in the long direction) is larger than the mesh 22 of the mesh body 20 in a plan view. The plate member 30 can adopt various shapes such as a circle, an ellipse, and a polygon in a plan view, and is formed in a substantially hexagonal shape in the present embodiment.

It is preferable that one or more protrusions 36 protruding from the lower surface 32 be formed on the lower surface 32 (that is, the surface facing the slope S) side of the plate material 30. In this embodiment, the lower surface 32 has six protrusions 36. The length of the protrusion 36 is equal to or greater than the thickness d of the net body 20.

A cushioning member 35 for abrasion resistance is arranged between the plate member 30 and the net body 20. In this embodiment, the buffer 35 is a film integrally formed on the surface of the plate material 30 as shown by dots in FIG. 7. The cushioning body 35 can be formed of, for example, a rubber material or a resin material, and when it is integrated with the plate material 30, it is preferably formed on at least a contact surface with respect to the net body 20. In the present embodiment, the coating film which is the buffer 35 is formed on the side surface 33 of the plate material 30 and the lower surface 32 of the plate material 30 including the protrusion 36, but the invention is not limited to this, and only the lower surface 32 or the entire surface. It may be formed in. Further, a sheet-shaped cushioning body 35 which is a separate body from the plate material 30 may be arranged between the net body 20 and the plate material 30. In such a case, it is preferable that the cushioning body 35 has flexibility.

As shown in FIGS. 2 and 8, the plate member 30 is placed on the net body 20 with the anchors 14 passing through the through holes 34 so that the protrusions 36 penetrate the mesh 22 of the net body 20. Is located in. The plate member 30 is fixed to the head of the anchor 14 by the cap nut 50 fastened to the top of the anchor 14 while the spacer 40 restrains the plate member 30 from moving toward the slope S. In this way, by placing the protrusions 36 in the mesh 22, when an external force is applied to the mesh 20 and the relative positions of the plate member 30 and the mesh 20 are about to shift, the protrusions The engagement structure between the portion 36 and the linear member 24 can prevent the mesh body 20 from being displaced.

Next, a method of constructing the slope protection structure 10 described above will be described.

First, as shown in FIG. 9, on the slope S on which the method frame 12 is installed, the anchor 14 is driven in the non-arranged region of the method frame 12 (anchor driving step). In the present embodiment, a plurality of anchors 14 are placed at intervals on the slope S so that one anchor 14 exists in each rectangular frame of the grid-shaped normal frame 12.

The anchor 14 is placed in the following procedure. First, the slope S is drilled to a predetermined depth using a boring machine (not shown), and then a grout material injection hose (not shown) is inserted to the bottom of the boring hole 19 to remove cement milk, mortar, or the like. The grout material 18 is poured into the drilled hole 19 from the bottom of the hole. After the grout material 18 is filled up to the vicinity of the slope S, the underlayment material 16 and the spacer 40 are arranged on the slope S. At this time, the underlayment material 16 and the spacers 40 are arranged so that the drilled holes 19 communicate with the through holes of the underlayment material 16 and the hollow inside of the spacer 40. After that, the grout material 18 that is the same material as the grout material 18 in the drilled hole 19 is filled in the spacer 40. After the grout material is injected, the anchor 14 is inserted into the hole so as to penetrate the spacer 40 and the underlay material 16, and the grout material 18 is cured. As a result, the grout material 18 in the spacer 40 and the grout material 18 around the anchor 14 on the ground side of the spacer 40 are integrated.

The anchor 14 may be placed by inserting the anchor 14 into the drilled hole 19 and then injecting the grout material 18 after drilling. In such a case, after the grout material 18 is filled up to the vicinity of the slope S, the underlayment material 16 and the spacer 40 may be arranged at a predetermined position from the head side of the anchor 14 and the grout material 18 may be injected into the arranged spacer 40. it can.

After the anchor 14 is driven, as shown in FIG. 10, the net 20 is laid on the slope S from above the method frame 12 (net laying step). The net body 20 of the present embodiment is formed in a size capable of covering the entire surface of the arrangement region of the law frame 12 on the slope S.

Next, as shown in FIGS. 2 and 4, the plate member 30 is attached to the head of the anchor 14 from above the net body 20, and the plate member 30 is used to move the net body 20 to the height of the top surface 12 c of the method frame 12. Push down to a lower position (plate material installation process). The plate member 30 is fixed by fastening the cap nut 25 to the head of the anchor 14 with the head of the anchor 14 inserted through the through hole 34. With the plate material 30 fixed to the anchor 14, the protrusions 36 of the plate material 30 are inserted into the mesh 22 of the mesh body 20. As shown in FIG. 8, it is preferable that at least a part of the protruding portion 36 is located at the bent portion of the linear member 24 (that is, the corner portion of the diamond-shaped mesh 22). Further, when the linear member 24 comes into contact with the spacer 40 and the upper end portion 42 a in a state where the net body 20 is pushed down, the linear member 24 is inserted into the groove portion 46 of the spacer 40.

Thus, by fixing the net body 20 covering the slope S from above the method frame 12 to the slope S using the anchor 14, the underlay material 16, the spacer 40, the plate material 30, and the cap nut 50, the protective structure 10 is provided. It is formed.

In the slope protection structure 10 described above, the slope protection performance of the slope 12 can be improved by pressing the slope 12 against the slope S by the net 20. Further, even in the region in each frame where the legal frame 12 is not arranged, the anchor 14 is driven up to the stable formation G1 and further pressed by the net 20 from above, whereby slope collapse can be prevented. In particular, in the present embodiment, the net body 20 is composed of the wire rod 24 manufactured from the hard steel wire rod having the tensile strength of 800 to 2000 N/mm ² , so the net body 20 is less likely to be plastically deformed, It can exhibit high tensile strength and spring properties. As a result, not only can the collapse of the surface of the slope be prevented, but also slippage of the surface layer having a depth of 1 to 3 m from the surface of the slope can be prevented.

Further, in the protective structure 10, since the zinc plating layer or the zinc aluminum alloy plating layer having an adhesion amount of 80 g/m ² or more is formed on the surface of the net body 20 used, the net body 20 and the method frame are formed. Even under the condition of rubbing against 12, it is possible to maintain the anticorrosion performance of the net 20 and provide a structure with excellent durability.

Further, in the present embodiment, by providing the cushioning member 35 on the surface of the plate member 30, it is possible to prevent the mesh member 20 and the plate member 30 from rubbing against each other and abrasion of the surface of the mesh member 20. As a result, the anticorrosion performance of the net 20 can be improved. Further, by inserting the linear member 24 forming the net body 20 into the groove portion 46 of the spacer 40, it is possible to prevent the net body 20 from rubbing against the spacer 40 and being worn, and to improve the anticorrosion performance of the net body 20. It can be increased. Although not shown, when a protective coating is provided on the surface of the spacer 40, the effect of suppressing wear can be further enhanced.

Further, in the present embodiment, the head portion of the anchor 14 protruding from the slope S is covered with the cap nut 40 and the grout material 18 filled in the spacer 40, so that the exposed area of the anchor 14 is reduced. It can be reduced to prevent the generation of rust, and thereby the corrosion resistance of the anchor 14 can be enhanced.

FIG. 11 shows a modified example of the protective structure 10. In the example shown in FIG. 11, a cushion material 28 for abrasion resistance is arranged between the method frame 12 and the net body 20. The cushion material 28 may be, for example, a sheet having a thickness of 2 to 3 mm and formed of a resin material, a rubber material, or the like. Will be placed. By arranging the cushion material 28 in this manner, it is possible to prevent the net body 20 from being worn and further improve the corrosion resistance.

Next, another embodiment of the protective structure 10 will be described with reference to FIG. As shown in FIG. 12(A), in the protective structure 10 of the present embodiment, a greening base material 60 capable of growing a plant housed inside the bag body 62 is further provided between the slope S and the net body 20. Are arranged. As the greening base material 60, for example, a material obtained by cutting grass, felled wood, thinned wood, or the like (vegetation base material) mixed with plant seeds can be used.

FIG. 12B is a plan view of the bag body 62 into which the greening base material 60 is injected, and the law frame 12 is shown by an imaginary line so that the installation position with respect to the law frame 12 can be easily understood. The bag body 62 has a bag portion 64 made of a cloth knitted with a biodegradable thread, and an injection portion 68 for injecting the greening base material 60 into the bag portion 64. The bag portion 64 has air permeability and water permeability. At least one bag 62 is preferably arranged in each rectangular frame so as to cover substantially the entire area of each rectangular frame. The bag body 62 of the present embodiment has a hole 66 at the center of the bag portion 64 through which the anchor 14 can pass. Note that the bag body 62 may have a rectangular shape without the holes 66 instead of the illustrated example, and in such a case, the bag body 62 surrounds the anchor 14 in a plan view in one grid frame. A plurality (for example, 2 to 4) may be arranged around the anchor 14 so as to fill the inside.

In the protective structure 10 of this embodiment, the greening base material 60 is installed in the following procedure. After the anchor placing process, the bag body 62 is arranged in each frame of the method frame 12. At this time, the greening base material 60 is not injected into the bag body 62. Next, the net body 20 is laid from the method frame 12 and the bag body 62 (net body laying step), and then the plate member 30 is attached to the head of the anchor 14 and the net body 20 is pushed down to the slope S side ( Plate material installation process). After the plate material 30 is attached, the fluidized greening base material 60 is injected into the bag portion 62 from the injection portion 68 of the bag body 62 (greening base material injection step). In addition, the injection part 68 may be removed from the bag part 64 after the greening base material 60 is injected. Moisture of the greening base material 60 evaporates over time and changes from a liquid state to a solid state.

In this way, by installing the greening base material 60 between the slope S and the net 20, it is possible to green the non-installed area of the method frame 12, and as a result, the slope surface portion exposed to the wind and rain is exposed. The outflow of sediment can be suppressed. In addition, before the plate material installation step, the bag body 62 is arranged on the slope S, the plate material 30 is arranged on the bag body 62, and then the greening base material 60 is injected. Also in the region between and, the greening base material 60 can be appropriately filled. In the example shown in FIG. 12, a grouting material such as mortar or soil may be injected into the bag body 62 instead of the greening base material 60.

FIG. 13 shows another embodiment of the slope protection structure 10 including the greening base material 60. In the present embodiment, after the net 20 is fixed to the slope S (after the plate material installation step), the base material spraying machine 70 is used to pass the mesh 22 from above the net 20 to the green S base 60 on the slope S. The greening base material 60 is injected between the slope S and the net 20 by spraying (greening base material injection step). The greening base material 60 is sprayed onto the area of the slope S where the legal frame 12 is not arranged. In this way, the greening base material 60 may be arranged on the slope S by spray injection.

Next, still another embodiment of the slope protection structure 10 will be described with reference to FIG. In this embodiment, the structure of the method frame 12 is different from that of the previous embodiment shown in FIGS. 1 to 13, and the net body 20, the anchor 14, the underlay material 16, the spacer 40, the plate material 30, the cap nut 30. Since the structures are the same, detailed description of these same structures will be omitted.

In the present embodiment, the law frame 12 installed on the slope S is composed of a plurality of cross-shaped blocks 11 arranged apart from each other. The block 11 is formed, for example, by placing concrete on a reinforcing bar assembled in a cross shape. In each block 11, an anchor 13 extending to the stable formation G1 is placed at the center of the cross. As described above, the law frame 12 may be composed of a plurality of separated blocks 11. Further, the shape of the block 11 is not limited to the cross shape in plan view as in the illustrated example, and various shapes such as a rhombus shape in plan view can be adopted.

In the protective structure 10 of the present embodiment, an anchor 14 for fixing the net 20 is placed on the slope S of the non-arranged area of the block 11, and then the net 12 is applied from above the method frame 12 including the plurality of blocks 11. 20 are laid. After that, the net body 20 is pushed down to a position lower than the top surface of the block 11 by the plate material 30 fixed to the head of the anchor 14. In addition, in the protective structure 10 of the present embodiment, a greening base material 60 may be further provided between the slope S and the net 20.

The present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the invention.

10 Slope protection structure 11, 12 Normal frame 12a Vertical frame member 12b Horizontal frame member 14 Anchor 16 Underlay material 18 Grout material 20 Net body 30 Plate material 40 Spacer 50 Cap nut 60 Greening base material 62 Bag body G1 Stable formation G2 Unstable formation

Claims (6)

In the protection structure of the slope where the law frame for slope stabilization was installed,
A plurality of anchors placed at intervals in the non-existing region of the law frame within the installation range of the law frame,
A net body made of a rhombus wire net laid on the slope from above the method frame,
A plate member that is attached to the head of the anchor and presses the mesh body to a position lower than the height position of the top surface of the method frame to apply tension to the mesh body;
The wire material forming the net body is a wire material made of a hard steel wire material, and has a zinc plating layer or a zinc aluminum alloy plating layer having an adhesion amount of 80 g/m ² or more on the surface. Characteristic slope protection structure. A cylindrical spacer disposed between the plate member and the slope and surrounding the outer periphery of the anchor,
The slope protection structure according to claim 1, wherein the spacer is filled with grout material. The slope protection structure according to claim 1 or 2, wherein a cushioning body for abrasion resistance is provided between the plate member and the net body. The linear material forming the mesh has a diameter of ² to 5 mm and a tensile strength of 800 to 2000 N/mm ² , and the linear material according to claim 1. Slope protection structure. In the method of protecting slopes where a legal framework for slope stabilization has been installed,
An anchor placing step of placing a plurality of anchors at intervals in the non-existing region of the law frame within the installation range of the law frame,
A net body laying step of laying a net body made of a rhombus wire net on the slope from above the method frame,
A plate member setting step of fixing the plate member to the anchor in a state where the net member is pushed down to a position lower than the top surface height position of the method frame by a plate member having a diameter larger than the mesh of the net member; Including,
The wire material forming the net body is a wire material made of a hard steel wire material, and has a zinc plating layer or a zinc aluminum alloy plating layer having an adhesion amount of 80 g/m ² or more on the surface. Characteristic slope protection method. The method for protecting a slope according to claim 5, further comprising a step of injecting a green base material between the slope and the net after the plate material installation step.

Images