JP6341884B2 - Shed and retaining wall - Google Patents

Description

The present invention relates to a shed and retaining wall that protects roads and railway tracks along mountains from falling rocks and landslides.

  Conventionally, for example, as disclosed in Patent Document 1, there has been a protective structure in which a foamed polystyrene block is laid on a protective surface (such as an upper surface of a concrete roof) for receiving a fallen object to form a buffer layer. This buffer layer is formed by stacking expanded polystyrene in two upper and lower layers, placing a foamed polystyrene block having a small unit volume weight and compressive stress in the lower layer, and placing a foamed polystyrene block having a large unit volume weight and compressive stress in the upper layer, The shock received at the local area is effectively dispersed to improve the buffer function.

  In addition, as disclosed in Patent Document 2, there is a rock fall protection protective structure in which a foaming synthetic resin block is laid on a protective surface for receiving a fallen fall object to form a buffer layer. The foamable synthetic resin used is foamed polystyrene, foamed polyethylene, foamed polypropylene, or foamed urethane. Moreover, the impact absorption capacity of each block is improved by winding a net etc. around each block.

JP-A-10-159030 JP 2010-106514 A

Styrofoam, foamed polyethylene, foamed polypropylene, and foamed urethane used in the buffer layers of Patent Documents 1 and 2 are materials that are not very good in shape recovery when the external pressure is removed after being deformed by external pressure. . Therefore, for example, when multiple rockfalls occur in succession, after receiving the first rockfall, the shape will not be fully restored, and the next rockfall will be received in a state where the buffering performance has deteriorated. There was a problem to say .

This invention is made in view of the said background art, and it aims at providing the shed and retaining wall which can suppress the impact added to a protective surface small even when a plurality of falling rocks etc. continue. .

The present invention is a shed that protects a passage provided along a slope of a mountain from falling objects such as falling rocks and earth and sand, and an EVA resin foam on an upper surface (protective surface) of a roof portion that covers an upper portion of the passage. The first buffer layer is formed by alternately layering a high hardness EVA resin foam layer and a low hardness EVA resin foam layer in the thickness direction, It is a shed in which a layer of the high hardness EVA resin foam is disposed on the side close to the slope.

In this case, a second buffer layer is provided between the protective surface and the first buffer layer, and the second buffer layer is arranged with buffer blocks made of resin foam in a rectangular parallelepiped shape. Each of the buffering block bodies is covered with a net on each of the six surfaces, and the adjacent buffering block bodies are connected to each other at adjacent portions of the nets by a connector. Therefore, the configuration may be fixed to each other. Moreover, it is preferable that a protective layer having a light shielding property is provided on the surface layer closest to the slope.

Further , the present invention is a retaining wall that protects a passage provided along a slope of a mountain from falling objects such as falling rocks and earth and sand, and the slope of the wall body portion standing on the side of the passage. A first buffer layer made of EVA resin foam is provided on the side surface (protective surface), and the first buffer layer includes a layer of high-hardness EVA resin foam and a layer of low-hardness EVA resin foam. Is a retaining wall in which layers of the high-hardness EVA resin foam are disposed on the side close to the inclined surface . In this case, it is preferable that a protective layer having a light shielding property is provided on the surface layer closest to the slope. The protective layer includes a protective block body formed by putting an aggregate of granular materials in a bag and filling the inside of a wire mesh frame having a rectangular parallelepiped shape, and a plurality of the protective block bodies are provided. The protective block bodies, which are formed by stacking in a wall shape and are adjacent to each other vertically and horizontally, are configured to be fixed to each other by connecting adjacent portions of the wire mesh frame with a connector. Also good.

The shed and retaining wall of the present invention is provided with a first buffer layer made of an EVA resin foam excellent in shape restoration on the protective surface that receives the fallen fallen object, so even when a plurality of falling rocks are continuous. The impact on the protective surface can be kept small. In particular, by using an EVA resin foam having a predetermined hardness having shock absorption and restoration properties against rock fall or the like, it is possible to provide a large buffering performance.

  Further, the first buffer layer is formed by alternately arranging a layer of high-hardness EVA resin foam and a layer of low-hardness EVA resin foam in the thickness direction, and foams high-hardness EVA resin on the side closest to the slope. By adopting a structure in which the body layers are arranged, it is possible to more effectively disperse and absorb impacts such as falling rocks and to further improve the buffer performance.

It is sectional drawing (a) and front view (b) which show one Embodiment of the shed of this invention. It is the figure which expanded the upper part from the roof part of FIG.1 (b). It is the figure (a) which expanded the A section of Drawing 1 (a), and the figure (b) which saw through the cast-in-place concrete layer. It is the front view (a) which shows the external appearance of the precast slab used with the shed of this embodiment, a top view (b), and the figure (c) which expanded the side. It is the front view (a) which saw through the concrete main body of the precast floor slab of FIG. 4, the top view (b), and the figure (c) which expanded the side surface. It is the top view, right view, and front view which show the state which laid the precast floor slab of FIG. 4, and connected with the connection member. It is a perspective view (a) which shows each structure of the block body for a buffer used with the shed of this embodiment, and is a perspective view (b) which shows the state which combined four buffer blocks. It is a figure which shows the modification of the 1st buffer layer of the shed of this embodiment. It is a perspective view which shows the external appearance of one Embodiment of the retaining wall of this invention. It is sectional drawing of the BB part of FIG. It is sectional drawing which shows the 1st modification of the retaining wall of this embodiment. It is sectional drawing (a) which shows the 2nd modification of the retaining wall of this embodiment, and sectional drawing (b) which shows a 3rd modification. It is the graph which measured the stress-strain characteristic of the EVA resin foam used for experiment, and a polystyrene foam. It is the graph which measured the stress-strain characteristic when not covering the expanded polystyrene. It is the graph which measured the stress-strain characteristic when changing the number of layers of the layer of the EVA resin foam of high hardness, and the layer of the EVA resin foam of low hardness.

Hereinafter, an embodiment of a shed according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the shed 10 according to this embodiment is installed above a passage T provided along a slope S of a mountain, and protects the passage T from falling rocks and landslides.

  The shed 10 has a plurality of receiving beams 12 provided above the passage T. The receiving beam 12 is a thick prismatic concrete material, and is arranged in the width direction of the passage T and is installed at a predetermined interval in the length direction of the passage T. Each receiving beam 12 has an end on the slope S side of the mountain supported by the upper end of the support wall 14, and the opposite end is individually supported by the upper ends of the plurality of columns 16.

  A roof portion 18 is provided above the receiving beam 12 so as to cover the upper side of the passage T, and the upper surface of the roof portion 18 serves as a protective surface 18a for receiving sloping falling objects such as falling rocks and earth and sand. The roof portion 18 has a two-layer structure in which an in-situ concrete layer 22 is superimposed on the upper surface of the floor slab layer 20, and the floor slab layer 20 includes a plurality of precast floor slabs 24 as shown in FIGS. It is formed using. In FIG. 3, members (first and second cushioning material layers and the like described later) provided above the roof portion 18 are omitted.

  As shown in FIGS. 4 and 5, the precast floor slab 24 is composed of a concrete body 26, a plate 28 for reinforcing the same, a covering plate 30 covering the lower surface of the concrete body 26, and the like, and is manufactured in advance at a factory. , Transported to the mountainous site. The precast floor slab 24 has a substantially rectangular outer shape in plan view, the long side is set to a length that allows both ends to be installed between the pair of receiving beams 12, and the short side is the length of the receiving beam 12. The length is set to a length that allows a predetermined number of sheets to be well separated in the direction, and the thickness is set to a predetermined value in consideration of strength and the like.

  The plate 28 is made of a tough metal plate such as an H steel material, has a rectangular plate-shaped main body 28a, its upper end portion 28b and lower end portion 28c are formed in a flange shape, and a longitudinal section having a large second moment of section. It is formed into a shape. The length of the plate 28 is slightly short so as not to protrude from the concrete body 26, and the height from the lower end 28 c to the upper end 28 b is higher than the thickness of the concrete body 26, and the upper end 28 b protrudes from the upper surface of the concrete body 26. ing. The protruding length is such that the upper end portion 28b is buried in a cast-in-place concrete layer 22 described later. The reason why the upper end portion 28b of the plate 28 protrudes from the upper surface of the concrete body 26 will be described later.

  The concrete body 26 is provided with two thin portions 26a. The thin portion 26 a is provided by denting the lower surface side of the portion where the plate 28 is not provided along the plate 28 into a groove shape. Thereby, the volume of the concrete main body 26 is made small, and the weight reduction and cost reduction of the precast floor slab 24 are aimed at.

  The covering plate 30 is an iron plate or the like, is in close contact with the lower surface of the concrete body 26, and covers the entire lower surface. Further, the inner side surface is joined to the lower end portion 28c of the plate 28 by welding or the like. The covering plate 30 absorbs an impact caused by falling rocks, enhances the proof stress performance of the precast floor slab 24, and prevents a part of the concrete body 26 from peeling off into the passage T. Further, when the precast floor slab 24 is manufactured, it is used as a mold for placing the concrete body 26.

  When the floor slab layer 20 is assembled on site, a necessary number of precast floor slabs 24 are laid on the upper surface of the receiving beam 12 to cover the upper side of the passage T as shown in FIGS. And in order to integrate the several precast slab 24 located in a line with the width direction of the channel | path T, as shown in FIG. 6, the upper end part 28b of the plate 28 which protrudes from the upper surface of each concrete main body 26 is a reinforcing bar etc. They are fixed to each other via a plurality of connecting members 32. By fixing with the connecting member 32 in this manner, the shear resistance between the precast slabs 24 arranged in the width direction of the passage T can be improved.

  Next, in order to integrate the plurality of precast slabs 24 arranged in the length direction of the passage T, the upper end portions 28b of the plates 28 protruding from the upper surface of each concrete body 26 are connected to a plurality of connecting members 34 such as reinforcing bars. To fix each other through. By fixing with the connecting member 34 in this manner, the shear resistance between the precast slabs 24 arranged in the length direction of the passage T can be improved. Further, in FIG. 6, the plurality of connecting members 32 are also fixed to each other via connecting members 36. The connecting member 36 functions in the same manner as the connecting member 34.

  The cast-in-place concrete layer 22 on the floor slab layer 20 is placed so that the entire plate 28 and the connecting members 32, 34, and 36 are buried. By providing the cast-in-place concrete layer 22, the strength of the roof portion 18 is improved, and the joints between the precast floor slabs 24 laid can be shielded. Further, since the upper portion of the plate 28 of the floor slab layer 20 is fitted into the spot cast concrete layer 22, the bonding force between the spot cast concrete layer 22 and the floor slab layer 20 can be increased.

  As described above, the roof portion 18 of the shed 10 is constituted by the floor slab layer 20 and the in-situ concrete layer 22, and the upper surface of the in-situ concrete layer 22 serves as a protective surface 18 a that receives falling rocks, earth and sand, and the like.

  As shown in FIG. 1A, an enclosure wall 38 that supports the side surfaces of first and second cushioning material layers and a laid sand layer, which will be described later, is erected on the end portion of the roof portion 18 on the column 16 side. . In addition, the enclosure wall 38 is abbreviate | omitted in FIG.1 (b) and FIG. A second buffer layer 40 is provided on the protective surface 18 a of the roof portion 18. As shown in FIGS. 1 and 2, the second buffer layer 40 is formed by arranging a plurality of buffer blocks 42.

  As shown in FIG. 7, the buffer block 42 is a unit rectangular parallelepiped formed by combining small resin foams 44 such as polystyrene foam, and the six surfaces of the unit rectangular parallelepiped are nets made of metal or synthetic resin, respectively. Are covered with six nets 46. The corresponding ends of the net 46 are arranged on the ridge line portion of the hexahedron, are connected using a connecting tool (not shown), and enclose the small resin foam 44 inside. The structure in which the six surfaces are formed by the net 46 may be a structure in which a plurality of surfaces are formed by a single net 46, thereby reducing the labor of connecting the edges.

  The buffer block bodies 42 are arranged on the upper surface of the roof portion 18 so as to be aligned with almost no gap, and the adjacent buffer block bodies 42 are connected to each other by the ridge portions of the nets 46 that cover each other and face each other. Are connected to each other and fixed to each other. The connecting tool 48 is preferably a spiral metal wire. For example, a plurality of connecting portions 48 are prepared according to the length of the end side of the buffer block body 42, and are entangled through the meshes of both portions to be connected. Thereby, the ridgeline part of the block body 42 for buffering can be closely connected.

  Since each buffer block 42 is covered with a net 46 having a certain rigidity and stretchability, it can be integrally deformed by its restraining effect. Moreover, since the nets 46 of the adjacent buffer block bodies 42 are connected to each other, the impact received by the specific buffer block body 42 can be efficiently distributed to the surrounding buffer block bodies 42. . Further, when a spiral metal wire is used as the connecting tool 48, when one of the nets 46 is strongly pulled, the spiral metal wire expands or contracts in the diametrical direction, so that it is difficult to break at the connecting portion.

  On the second buffer layer 40, a first buffer layer 50 made of EVA resin foam is provided. EVA resin foam is obtained by foaming ethylene / vinyl acetate copolymer resin at a predetermined expansion ratio, and has higher elasticity than other resin foams such as expanded polystyrene, and its shape recovery after deformation. Is excellent. The first buffer layer 50 has a two-layer structure in which a high-hardness EVA resin foam layer 54 is arranged on the upper surface of a low-hardness EVA resin foam layer 52. The low-hardness EVA resin foam layer 52 on the protective surface 18a side is formed, for example, by stacking thin plates made of EVA resin foam having a hardness of 10 to 20 (herein, Asker C hardness, hereinafter simply referred to as hardness), The high-hardness EVA resin foam layer 54 on the side close to the slope S of the mountain is formed, for example, by stacking thin plates made of EVA resin foam having a hardness of about 40 to 60.

  Further, as shown in FIGS. 1 and 2, a protective layer 56 formed by laying sand or the like so as to cover the upper surface of the first buffer layer 50 is provided on the first buffer layer 50. Yes. The protective layer 56 shields and protects the first buffer layer 50 while improving the buffer performance against impacts such as falling rocks. The protective layer 56 made of sand can be replaced with a light-shielding sheet.

  According to the shed 10 configured as described above, since the first buffer layer 50 made of the EVA resin foam having excellent shape restoring property is provided on the protective surface 18a of the roof portion 18, a plurality of falling rocks are provided. Even in the case of continuous, the impact applied to the protective surface 18a can be kept small.

  In addition, the first buffer layer 50 is formed by overlapping the low-hardness EVA resin foam layer 52 and the high-hardness EVA resin foam layer 54 in the thickness direction, and the upper layer (the side closest to the slope S). Since the layer 54 of the EVA resin foam having a high hardness is disposed, it is possible to more effectively disperse and absorb impacts such as falling rocks and to obtain excellent buffering performance. Further, the structure of the first buffer layer 50 is changed, and a high hardness is provided between the protective surface 18a and the low hardness EVA resin foam layer 52 as in the first buffer layer 58 shown in FIG. If a layer 60 of EVA resin foam is added to form a three-layer structure, the buffer performance can be further improved. In addition, by omitting the low-hardness EVA resin foam layer 52 and providing the thicker high-hardness EVA resin foam layer 60 as the first buffer layer 58, a shed that can withstand even greater impacts. 10 can also be formed.

Next, one embodiment of the retaining wall of the present invention will be described with reference to FIGS. Here, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. The retaining wall 62 of this embodiment is installed on the side of the slope S side of the passage T provided along the slope S of the mountain as shown in FIGS. 9 and 10, and protects the passage T from falling rocks and landslides. To do.

  The retaining wall 62 has a wall main body 64 made of concrete. The wall main body 64 has a lower end embedded in the ground and fixed, and a surface on the slope S side (a surface formed substantially perpendicular to the ground) is a protective surface 64a that receives sloping fallen objects such as falling rocks and earth and sand. It becomes.

  A first buffer layer 66 made of EVA resin foam is provided on the slope S side of the protective surface 64a. Similarly to the above, the first buffer layer 66 has a two-layer structure in which a low-hardness EVA resin foam layer 52 and a high-hardness EVA resin foam layer 54 are stacked in the thickness direction. The layer 54 of the EVA resin foam having the hardness is arranged on the side closer to the slope S.

  Furthermore, a protective layer 68 is provided on the slope S side of the first buffer layer 66 to cover the slope S side surface of the first buffer layer 66. The protective layer 68 is formed by a plurality of protective block bodies 70.

The protection block 70 is obtained by putting granular aggregates 70a (sand, single-grain crushed stone, etc.) in a bag and filling them inside a wire mesh frame 70b having a rectangular parallelepiped shape. The protection block bodies 70 are stacked so as to cover the first buffer layer 66, and the protection block bodies 70 that are adjacent to each other in the vertical and horizontal directions are connected to each other with the ridge portions of the metal mesh frame 70b by the connector 48, Fixed to each other. In the case of the buffer block body 42 described above, a net made of synthetic resin can be used for the net 46 covering the surface. However, in the case of the protection block body 70, it is stacked up and down. In order to stabilize the structure, a wire mesh frame 70b having a certain rigidity is used. The protective block 70 located at the lower end is fixed to the ground by an anchor 72. The protective layer 68, like the protective layer 56, protects the first buffer layer 66 by shielding the light, and falling rocks, etc. It works to improve the shock absorbing performance against shock. In particular, since each protective block 70 has a certain rigidity and is covered with a stretchable wire mesh, the protective block 70 is deformed as a whole due to its restraining effect, and the protective blocks 70 adjacent to each other. Since the metal mesh frames 70b are connected to each other, the impact received by the specific protective block body 70 can be efficiently dispersed in the surrounding protective block bodies 70. In addition, when a spiral metal wire is used as the connector 48 and one of the wire mesh frames 70b is pulled strongly, the spiral metal wire expands or contracts in the diametrical direction and is not easily broken.

  Further, as shown in FIG. 9, the side end surface of the first buffer layer 66 located at the end portion of the retaining wall 62 is covered with a fore edge stop portion 74 formed by stacking block bodies similar to the protection block body 70. Protected. 9 and 10, the upper end surface of the first buffer layer 66 is exposed, but it is preferable to protect this portion by covering it with a light shielding sheet (not shown).

  According to the retaining wall 62 configured as described above, the first buffer layer 66 made of the EVA resin foam having excellent shape restoring properties is provided on the protective surface 64a of the wall main body portion 64. Even when the falling rocks continue, the impact applied to the protective surface 64a can be kept small.

  Also, the first buffer layer 66 is formed by overlapping the low hardness EVA resin foam layer 52 and the high hardness EVA resin foam layer 54 in the thickness direction, and has a high hardness near the slope S. Since the EVA resin foam layer 54 is disposed, it is possible to more effectively disperse and absorb impacts such as falling rocks and to obtain excellent buffer performance.

  Further, like the first buffer layer 76 shown in FIG. 11, a layer 78 of high-hardness EVA resin foam is provided between the protective surface 64a of the wall main body 64 and the layer 52 of low-hardness EVA resin foam. If a three-layer structure is added, the impact acting on the protective surface 64a can be more widely dispersed, and the buffer performance can be further improved than the first buffer layer 66.

  In addition, the protective structure of this invention is not limited to the said embodiment. For example, the above-described shed 10 is provided with a unique second buffer layer 40 and a protective layer 56 in addition to the first buffer layer 50 in order to increase the buffer performance, but in order to simplify the structure, The second buffer layer 40 and the protective layer 56 may be omitted. Further, an EVA resin foam may be used as the small resin foam 44 of the second buffer layer 40.

  The retaining wall 62 is provided with a unique protective layer 68 in addition to the first buffer layer 66 in order to enhance the buffer performance. However, to simplify the structure, the protective layer 68 may be omitted. Good.

  In the case of the retaining wall 62, a concrete wall body 64 is provided, but a wall body block body 84 is stacked to form a wall body 86 as a retaining wall 82 shown in FIG. The surface on the slope S side of the wall main body 86 may be the protective surface 86a. The wall body block body 86 is obtained by putting sand or locally generated soil 86a in a bag and filling the inside of a wire mesh frame 86b having six rectangular parallelepiped shapes. The structure of the wall main body 86 is substantially the same as that of the protective layer 68 described above. Is also formed large. Furthermore, as shown in FIG. 12B, by changing the structure so that the lower end portions of the wall main body portion 86, the first buffer layer 66, and the protective layer 68 are embedded in the ground, the anchor 72 is used. The fixing strength can be increased. The wall main body 86 formed of the wall main body block 84 is superior to the wall main body 64 made of concrete, and can be planted and planted, for example. Moreover, since the process of placing concrete during construction can be omitted, the work can be performed efficiently without being influenced by the weather. Furthermore, when a damaged part is found in a part of the wall main body 86, only the wall main body block 84 in that part needs to be replaced, so that maintenance is easy. In addition, there is an advantage that the wall main body portion 86 and the protection portion 68 can be connected and integrated by the small mouth stopper portion 74 and the coupling tool 48.

With respect to the shed 10 of the first embodiment, the first buffer layers 50 and 58 and the block body 42 for buffering in which the foamed polystyrene was covered with the net 46 of the metal net were manufactured, and an experiment for evaluating the buffering performance was performed. Measurement of individual stress-strain characteristics of the low hardness EVA resin foam (hardness 16), the high hardness EVA resin foam (hardness 50), and the polystyrene foam (density 0.16 kN / m ³ ) used in the experiment. The values are as shown in FIG.

  First, in order to evaluate the shape restoration properties of EVA resin foam and polystyrene foam, an initial thickness dimension d1 of the small rectangular parallelepiped block made of each material and a constant load in the thickness direction are applied to the small rectangular parallelepiped block, and the load is removed. The thickness dimension d2 when 10 minutes passed was measured, and the shape restoration rate d2 / d1 was calculated.

表１の実験結果より、ＥＶＡ樹脂発泡体の方が発泡スチロールよりも優れた形状復元性を有していると言うことができる。

From the experimental results shown in Table 1, it can be said that the EVA resin foam has a shape restoring property superior to that of polystyrene foam.

  Next, a polystyrene foam having the size of the buffer block 42 (2050 mm × 2050 mm × 520 mm) was prepared, and the stress-strain characteristics in the thickness direction were measured for the sample with the 6 surfaces covered with a wire mesh and the sample not covered.

  From the measurement results in FIG. 14, it can be said that the foamed polystyrene sample covered with a wire mesh has a higher energy absorbability because the stress generated when the same strain is applied is larger.

  Next, the first buffer layer 50 (the upper layer of the low-hardness EVA resin foam layer is overlaid with the high-hardness EVA resin foam layer) is provided on the upper surface of the polystyrene foam whose six sides are covered with a metal mesh. Type B and a first buffer layer 58 (a layer of a low-hardness EVA resin foam layered so as to be sandwiched between two high-hardness EVA resin foam layers), Each stress-strain characteristic was measured.

  From the measurement results of FIG. 15, type A has a significantly improved energy absorption compared to the foamed polystyrene (see the data of FIG. 14) whose six sides are covered with a wire mesh, and the first buffer layer 50 is provided. It can be said that the effect is very large. In addition, type B has improved energy absorption compared to type A, and the effect of increasing the number of high and low hardness EVA resin foams to be stacked appears.

DESCRIPTION OF SYMBOLS 10 Shed 18 Roof part 18a, 64a Protective surface 40 Second buffer layer 42, 70 Buffer block body 46 Net 48 Connector 50, 58, 66, 76 First buffer layer 52 Layer of EVA resin foam of low hardness 54, 60, 78 High hardness EVA resin foam layers 56, 68 Protective layer 62 Retaining wall 64 Wall body 70a Granular aggregate 70b Wire mesh frame S Slope T Passage

Claims (6)

In a shed that protects a passage provided along a slope of a mountain from falling objects such as falling rocks and earth and sand , a first buffer layer made of EVA resin foam is provided on an upper surface of a roof portion that covers the passage. The first buffer layer is formed by alternately layering a high-hardness EVA resin foam layer and a low-hardness EVA resin foam layer in the thickness direction, and the high-hardness EVA resin foam layer is closer to the slope. A shed in which a layer of EVA resin foam is disposed . A second buffer layer is provided between the top surface of the roof portion and the first buffer layer;
The second buffer layer is formed by laying buffer blocks made of a resin foam in a rectangular parallelepiped shape, and each of the buffer blocks is covered with a net and adjacent to each other. the buffer block body by the portions between adjacent each other of said net being connected by a connecting member, Shed according to claim 1, characterized in that fixed to each other. The shed according to claim 1 or 2, wherein a protective layer having a light shielding property is provided on a surface layer closest to the slope. In the retaining wall that protects the passage provided along the slope of the mountain from falling objects such as falling rocks and earth and sand , the EVA resin foam is provided on the slope-side surface of the wall body portion standing on the side of the passage. The first buffer layer is formed by alternately layering a high hardness EVA resin foam layer and a low hardness EVA resin foam layer in the thickness direction, A retaining wall, wherein a layer of the high-hardness EVA resin foam is disposed on a side close to the slope . The retaining wall according to claim 4, wherein a protective layer having a light shielding property is provided on a surface layer closest to the slope. The protective layer includes a protective block body formed by putting an aggregate of granular materials in a bag and filling the inside of a wire mesh frame having a rectangular parallelepiped shape, and a plurality of the protective block bodies are provided. 6. The protective block bodies which are formed by stacking in a wall shape and are adjacent to each other in the vertical and horizontal directions are fixed to each other by connecting adjacent portions of the wire mesh frame with a connector. Retaining wall as described.

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