JP2021017707A - Lightweight banking structure - Google Patents

Abstract

To provide a lightweight banking structure which is hardly plastically deformed and has oil resistance, and thereby can exhibit a function as lightweight banking for a long period of time.SOLUTION: A lightweight banking structure 10 includes a banking part structured by stacking a plurality of foam blocks, a floor slab part provided between the vertically adjacent foam blocks or on the upper surface of the banking part, and a side wall part 8c covering the outside surface of the banking part and the outside surface of the floor slab part, in which the floor slab part has a concrete layer installed so as to planarly extend, and a resin block that is provided so as to be adjacent to the concrete layer in a surface direction and is made of polypropylene.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lightweight embankment structure.

As disclosed in Japanese Patent Application Laid-Open No. 11-241343 (Patent Document 1), in an anti-earth pressure structure such as a retaining wall or an abutment, in order to reduce the pressure (earth pressure) acting on the back side of the structure. , Lightweight earth pressure structure is adopted. By using a lighter foam block instead of soil on the back side of the structure, earth pressure can be reduced, the construction period can be shortened, and earthquake resistance can be improved.

In the lightweight embankment structure, foam blocks are laminated and a concrete slab is laid. The concrete slab is laid with a thickness of about 10 cm to 15 cm at a height of 3 m from the lower part of the foam block, for example. The vehicle load and pavement load, which are the loads from above on the laminated foam blocks, can be dispersed by the presence of the concrete slab. Even if petroleum that can dissolve the foam block leaks on the road surface, the presence of the concrete slab can protect the foam block from petroleum.

Japanese Unexamined Patent Publication No. 11-241343

When a large-scale earthquake occurs around an earth pressure structure such as a retaining wall or abutment, the concrete slab can press the side wall such as the abutment with a strong force. Due to the influence of the earthquake, the soil existing on the back side of the laminated foam blocks may indirectly act as earth pressure on the side wall portion such as the abutment via the concrete floor slab.

It is conceivable to arrange a cushioning material between the side wall such as the abutment and the concrete slab in order to alleviate the intensive pressing of the side wall such as the abutment by the concrete slab. As the material of the cushioning material, it is conceivable to use the same polystyrene as the foam block. However, when polystyrene is used, a part of the cushioning material may be plastically deformed as a result of compression of the cushioning material made of polystyrene between the side wall such as the abutment and the concrete floor slab. It is also conceivable that polystyrene is easily dissolved by contact with petroleum.

The present invention has been created in view of the above circumstances, and is more resistant to plastic deformation and has oil resistance, so that it can exhibit a function as a lightweight embankment for a longer period of time. , Aimed to provide a lightweight embankment structure.

The lightweight embankment structure based on the present invention is provided between the embankment portion formed by laminating a plurality of foam blocks and the foam blocks adjacent to each other on the upper and lower sides, or on the upper surface of the embankment portion. The floor slab portion is provided with an outer surface of the embankment portion and a side wall portion covering the outer surface of the embankment portion, and the floor slab portion is formed with a concrete layer cast so as to extend in a plane shape. It has a resin block made of polypropylene, which is provided adjacent to the concrete layer in the plane direction.

In the lightweight embankment structure, the resin block may be provided between the side wall portion and the concrete layer.

In the lightweight embankment structure, the concrete layer includes a first concrete portion and a second concrete portion arranged on the side opposite to the side wall portion with respect to the first concrete portion, and the resin block comprises. It may be provided between the first concrete portion and the second concrete portion.

The lightweight embankment structure further includes upper and lower claw-shaped binding metal fittings, which are between the lower surface of the resin block and the lower foam block and / or the upper surface and the upper surface of the resin block. It may be provided between the above-mentioned foam block.

According to the lightweight embankment structure, it is less likely to be plastically deformed and has oil resistance, so that the function as a lightweight embankment can be exhibited for a longer period of time.

It is sectional drawing which shows the lightweight embankment structure 10 in embodiment. FIG. 5 is an enlarged cross-sectional view showing a region surrounded by line II in FIG. 1. It is a perspective view which shows the binding metal fitting 6 applicable to a lightweight embankment structure 10. It is sectional drawing for demonstrating the operation and effect of the lightweight embankment structure 10 in embodiment. It is sectional drawing for demonstrating the operation and effect of the lightweight embankment structure 10a in the comparative example.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the following description, the same parts and equivalent parts may be given the same reference numbers, and duplicate explanations may not be repeated.

[Lightweight embankment structure 10]
The lightweight embankment structure 10 in the embodiment will be described with reference to FIGS. 1 and 2. The lightweight embankment structure 10 is for constructing a bridge or the like along a slope in a mountainous area, for example. FIG. 1 is a cross-sectional view showing the lightweight embankment structure 10 in the embodiment, and FIG. 2 is an enlarged cross-sectional view showing a region surrounded by line II in FIG.

As shown in FIGS. 1 and 2, the pier 8 for supporting the bridge 20 stands on the ground 7, and the lightweight embankment structure 10 is on the back side of the pier 8 (the side of the soil 9 when viewed from the pier 8). It is configured in. The abutment 8 has a pedestal portion 8a and a strut portion 8b, and a side wall portion 8c is formed on the side of the strut portion 8b. The lightweight embankment structure 10 includes a lower embankment portion 1, an intermediate floor slab portion 2, an upper embankment portion 3, an upper embankment portion 4, and a binding metal fitting 6 (see FIG. 3), and includes a bridge base 8 (side wall of the support column portion 8b). It is provided between the part 8c) and the soil 9. The lower embankment portion 1, the intermediate floor slab portion 2, the upper embankment portion 3, the upper floor slab portion 4, the roadbed 5a and the pavement 5b are laminated in this order. The soil 9 (backfill soil) is provided between the lower embankment portion 1 and the slope, and between the upper embankment portion 3 and the slope.

The binding metal fitting 6 (FIG. 3) is of the upper and lower claw type, and has a flat plate portion 6P, a plurality of lower claw portions 6S, and a plurality of upper claw portions 6U. The flat plate portion 6P has a square shape in a plan view, the plurality of lower claw portions 6S extend downward from the four sides of the flat plate portion 6P, and the plurality of upper claw portions 6U are the four sides of the flat plate portion 6P. Extends upward from. The flat plate portion 6P may have a polygonal shape such as a rectangle, a circular shape, an elliptical shape, or the like in a plan view.

(Lower embankment part 1)
As shown in FIGS. 1 and 2, the lower embankment portion 1 is configured by stacking a plurality of foam blocks 1a and binding them to each other by using a plurality of binding metal fittings 6. The binding metal fitting 6 is, for example, an upper and lower claw type binding metal fitting. The plurality of foam blocks 1a are made of the same material (for example, polystyrene) and are appropriately different in size. The outer surface of the lower embankment portion 1 located on the left side of the paper surface is covered with the side wall portion 8c of the abutment 8. The outer surface of the lower embankment portion 1 is arranged so as to contact the side wall portion 8c of the abutment pier 8.

(Intermediate floor slab 2)
As shown in FIG. 2, the intermediate floor slab portion 2 is provided on the upper surface of the lower embankment portion 1. The intermediate floor slab 2 is located between the vertically adjacent foam blocks 1a and 3a. The intermediate floor slab portion 2 further stabilizes the laminated state of the lower embankment portion 1 and disperses the load acting on the intermediate floor slab portion 2 in the in-plane direction, whereby the overall strength of the lightweight embankment structure 10 is achieved. To improve.

The intermediate slab portion 2 of the present embodiment includes an end resin block 2a, a concrete layer 2b (first concrete portion), an intermediate resin block 2c, and a concrete layer 2d (second concrete portion). The end resin block 2a and the concrete layer 2b are adjacent to each other in the surface direction, the concrete layer 2b and the intermediate resin block 2c are adjacent to each other in the surface direction, and the intermediate resin block 2c and the concrete layer 2d are adjacent to each other in the surface direction. They are next to each other.

The intermediate resin block 2c is provided between the concrete layer 2b and the concrete layer 2d. Both the end resin block 2a and the intermediate resin block 2c are made of polypropylene (PP).

The end resin block 2a has a shape extending in a direction perpendicular to the paper surface of FIGS. 1 and 2. The end resin block 2a is provided between the side wall portion 8c of the abutment 8 and the concrete layer 2b. The end resin block 2a typically has a rectangular parallelepiped shape, and its thickness is about 10 cm to 15 cm. The outer surface of the end resin block 2a located on the left side of the paper surface is covered with the side wall portion 8c of the abutment 8.

The outer surface of the end resin block 2a is arranged so as to be in contact with the side wall portion 8c of the abutment 8. It is preferable that the lower surface of the end resin block 2a is fixed to the uppermost foam block 1a of the lower embankment portion 1 by the upper and lower claw-shaped binding metal fittings 6. The concrete layer 2b can be easily cast by using the end resin block 2a as a part of the formwork. The upper surface of the end resin block 2a may be fixed to the foam block 3a in the lowermost layer of the upper embankment portion 3 by the upper and lower claw-shaped binding metal fittings 6.

The intermediate resin block 2c also has a shape extending in a direction perpendicular to the paper surface of FIG. 1, like the end resin block 2a. The intermediate resin block 2c is arranged on the side opposite to the side wall portion 8c with respect to the end resin block 2a, typically has a rectangular parallelepiped shape, and its thickness is about 10 cm to 15 cm. The lower surface of the intermediate resin block 2c may also be fixed to the uppermost foam block 1a of the lower embankment portion 1 by the upper and lower claw-shaped binding metal fittings 6. With the intermediate resin block 2c as a part of the formwork, the concrete layers 2b and 2d can be easily cast. The upper surface of the intermediate resin block 2c may be fixed to the foam block 3a of the lowermost layer of the upper embankment portion 3 by the upper and lower claw-shaped binding metal fittings 6.

The concrete layer 2b (first concrete portion) and the concrete layer 2d (second concrete portion) are concrete at positions on the upper surface of the lower embankment portion 1 where the end resin block 2a and the intermediate resin block 2c are not provided. Can be formed so as to extend in a plane shape by placing. An intermediate resin block 2c is provided between the concrete layers 2b and 2d. It is preferable that the concrete layers 2b and 2d are completely separated by the intermediate resin block 2c. A part of the concrete layers 2b and 2d may be connected to each other.

(Upper embankment part 3)
The upper embankment portion 3 on the intermediate floor slab portion 2 is configured by laminating a plurality of foam blocks 3a and binding them to each other by using a plurality of binding metal fittings 6. The binding metal fitting 6 is, for example, an upper and lower claw type binding metal fitting. The plurality of foam blocks 1a and 3a are made of the same material (for example, polystyrene), and those having different sizes are adopted. The outer surface of the upper embankment portion 3 located on the left side of the paper surface is covered with the side wall portion 8c of the abutment 8. The outer surface of the upper embankment portion 3 is arranged so as to be in contact with the side wall portion 8c of the abutment 8.

(Upper plate section 4)
As shown in FIG. 2, the upper floor slab portion 4 is provided on the upper surface of the upper embankment portion 3. A roadbed 5a and a pavement 5b are formed on the upper floor slab portion 4. The upper floor slab portion 4 further stabilizes the laminated state of the upper embankment portion 3 and disperses the load acting on the upper floor slab portion 4 in the in-plane direction to increase the overall strength of the lightweight embankment structure 10. Improve.

The upper plate bridge portion 4 of the present embodiment includes an end resin block 4a, a concrete layer 4b (first concrete portion), an intermediate resin block 4c, and a concrete layer 4d (second concrete portion). The end resin block 4a and the concrete layer 4b are adjacent to each other in the surface direction, the concrete layer 4b and the intermediate resin block 4c are adjacent to each other in the surface direction, and the intermediate resin block 4c and the concrete layer 4d are adjacent to each other in the surface direction. They are next to each other.

The intermediate resin block 4c is provided between the concrete layer 4b and the concrete layer 4d. The end resin block 4a and the intermediate resin block 4c are both made of polypropylene (PP).

The end resin block 4a has a shape extending in a direction perpendicular to the paper surface of FIGS. 1 and 2. The end resin block 4a is provided between the side wall portion 8c of the abutment 8 and the concrete layer 4b. The end resin block 4a typically has a rectangular parallelepiped shape, and its thickness is about 10 cm to 15 cm. The outer surface of the end resin block 4a located on the left side of the paper surface is covered with the side wall portion 8c of the abutment 8.

The outer surface of the end resin block 4a is arranged so as to be in contact with the side wall portion 8c of the abutment 8. It is preferable that the lower surface of the end resin block 4a is fixed to the uppermost foam block 3a of the upper embankment portion 3 by the upper and lower claw-shaped binding metal fittings 6. The concrete layer 4b can be easily cast by using the end resin block 4a as a part of the formwork. The upper surface of the end resin block 4a may be fixed to the roadbed 5a by the upper and lower claw-shaped binding metal fittings 6.

The intermediate resin block 4c also has a shape extending in a direction perpendicular to the paper surface of FIG. 1, like the end resin block 4a. The intermediate resin block 4c is arranged on the side opposite to the side wall portion 8c with respect to the end resin block 4a, typically has a rectangular parallelepiped shape, and its thickness is about 10 cm to 15 cm. It is preferable that the lower surface of the intermediate resin block 4c is also fixed to the foam block 3a of the uppermost layer of the upper embankment portion 3 by the upper and lower claw type binding metal fittings 6. With the intermediate resin block 4c as a part of the formwork, the concrete layers 4b and 4d can be easily cast. The upper surface of the intermediate resin block 4c may be fixed to the roadbed 5a by the upper and lower claw-shaped binding metal fittings 6.

For the concrete layer 4b (first concrete portion) and the concrete layer 4d (second concrete portion), concrete is placed on the upper surface of the upper embankment portion 3 at a position where the end resin block 4a and the intermediate resin block 4c are not provided. By placing it, it can be formed so as to extend in a plane shape. An intermediate resin block 4c is provided between the concrete layers 4b and 4d. It is preferable that the concrete layers 4b and 4d are completely separated by the intermediate resin block 4c. A part of the concrete layers 4b and 4d may be connected to each other.

(Action and effect)
FIG. 4 is a cross-sectional view for explaining the action and effect of the lightweight embankment structure 10 in the embodiment. FIG. 5 is a cross-sectional view for explaining the action and effect of the lightweight embankment structure 10a in the comparative example. The lightweight embankment structure 10a of the comparative example is different from the lightweight embankment structure 10 in that the intermediate floor slab portion 2 and the upper floor slab portion 4 are composed of only the concrete layer.

When a large-scale earthquake occurs around the lightweight embankment structures 10 and 10a, the intermediate slab portion 2 and the upper slab portion 4 may press the side wall portion 8c of the abutment 8. Due to the influence of the earthquake, the soil 9 existing on the back side of the laminated foam blocks 1a and 3a indirectly acts as earth pressure on the side wall portion 8c of the abutment 8 via the intermediate floor slab portion 2 and the upper floor slab portion 4. May also act on.

In FIGS. 4 and 5, the magnitude of the pressure acting on the side wall portion 8c is schematically represented by a polygonal line P1 (embodiment) and a polygonal line P2 (comparative example). In the lightweight embankment structure 10, the end resin blocks 2a and 4a can function as cushioning materials, and the intermediate slab portion 2 and the upper slab portion 4 can intensively and directly press the side wall portion 8c. It is relaxed as compared with the case of the comparative example (FIG. 5). Further, the presence of the intermediate resin blocks 2c and 4c also relaxes the stress transmission, and as a result, the intermediate floor slab portion 2 and the upper floor slab portion 4 alleviate pressing the side wall portion 8c. ..

Unlike the foam block, polypropylene (PP) is used as the material for these resin blocks. Polystyrene, for example, manufactured by the extrusion foaming method to have high strength in order to use resin blocks at some installation locations of concrete slabs for the purpose of distributing top loads (vehicle load and pavement load). In the case of a resin block made of concrete, the compressive force in the horizontal direction tends to be weaker than the compressive force in the vertical direction, and plastic deformation tends to occur in the horizontal direction. On the other hand, the cushioning material made of polypropylene is compressed even if it receives a sudden impact force between the side wall part such as the abutment and the concrete floor slab, or between the first concrete part and the second concrete part. Compared with the case of polystyrene, a part of the cushioning material is less likely to be plastically deformed, and it is easy to return to the state before compression. Furthermore, polypropylene is less likely to dissolve on contact with petroleum than in the case of polystyrene.

Therefore, according to the lightweight embankment structure 10 of the present embodiment, it is more difficult to be plastically deformed and has oil resistance, so that the function as a lightweight embankment can be exhibited for a longer period of time. If necessary, the oil-proof sheet may be further applied to the lightweight embankment structure 10, or a part of the lightweight embankment structure 10 may be covered with a material that prevents the penetration of petroleum. With these measures, it is possible to obtain a better effect. Even if these measures are not taken, as described above, it is more resistant to plastic deformation and has oil resistance, so that it can exhibit its function as a lightweight embankment for a long period of time.

As shown in FIG. 2, in the lightweight embankment structure 10, the lower surface of the end resin block 2a and the lower surface of the intermediate resin block 2c are further foamed on the uppermost layer of the lower embankment portion 1 by the upper and lower claw-shaped binding metal fittings 6. It is fixed to the body block 1a. By adopting these configurations, the integrity of the lower embankment portion 1 and the intermediate slab portion 2 is improved, and the intermediate slab portion 2 can press the side wall portion 8c of the abutment 8 locally. Seismic resistance is also improved by being suppressed and improving the overall integrity of the lightweight embankment structure 10. The same applies to the end resin block 4a and the intermediate resin block 4c.

The upper surface of the end resin block 2a and the upper surface of the intermediate resin block 2c are fixed to the foam block 3a of the lowermost layer of the upper embankment portion 3 by the upper and lower claw-shaped binding metal fittings 6. By adopting these configurations, the integrity of the intermediate floor slab portion 2 and the upper embankment portion 3 is improved, and the intermediate floor slab portion 2 is further suppressed from locally pressing the side wall portion 8c of the abutment 8. By improving the overall integrity of the lightweight embankment structure 10, seismic resistance is also improved. The same applies to the end resin block 4a and the intermediate resin block 4c.

The lightweight embankment structure 10 described in the above description is provided on a steep slope so that only one side forms a vertical wall. The technical idea disclosed in the above description can also be applied to a lightweight embankment structure configured so that both sides form vertical walls. The technical idea disclosed in the above description can also be applied to a lightweight embankment structure in which a plurality of floor slabs (intermediate concrete floor slabs) are laminated in multiple stages via an integrated embankment portion.

Although the embodiments have been described above, the above-mentioned disclosure contents are examples in all respects and are not restrictive. The technical scope of the present invention is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Lower embankment part, 1a, 3a foam block, 2 Intermediate floor slab part, 2a, 4a End resin block, 2b, 2d, 4b, 4d concrete layer, 2c, 4c Intermediate resin block, 3 Upper embankment part, 4 Upper floor slab, 5a roadbed, 5b pavement, 6 binding metal fittings, 6P flat plate, 6S lower claw, 6U upper claw, 7 ground, 8 abutment, 8a pedestal, 8b strut, 8c side wall, 9 soil 10,10a Lightweight embankment structure, 20 bridges, P1, P2 fold lines.

Claims (4)

An embankment part composed of multiple foam blocks laminated together,
A floor slab portion provided between the foam blocks adjacent to each other or on the upper surface of the embankment portion.
A side wall portion that covers the outer surface of the embankment portion and the outer surface of the floor slab portion is provided.
The floor slab is
A concrete layer placed so as to extend in a plane,
It has a resin block made of polypropylene, which is provided adjacent to the concrete layer in the plane direction.
Lightweight embankment structure. The resin block is provided between the side wall portion and the concrete layer.
The lightweight embankment structure according to claim 1. The concrete layer includes a first concrete portion and a second concrete portion arranged on the side opposite to the side wall portion with respect to the first concrete portion.
The resin block is provided between the first concrete portion and the second concrete portion.
The lightweight embankment structure according to claim 1 or 2. Further equipped with upper and lower claw type binding brackets,
The binding metal fitting is provided between the lower surface of the resin block and the lower foam block, and / or between the upper surface of the resin block and the upper foam block.
The lightweight embankment structure according to any one of claims 1 to 3.

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