JP4528176B2 - Lightweight embankment structure with buoyancy countermeasure structure - Google Patents

Description

  The present invention relates to a lightweight embankment structure, and more particularly to a lightweight embankment structure having a buoyancy countermeasure structure.

  As one embankment method on soft ground or landslide land, a lightweight embankment method using a resin foam block such as expanded polystyrene (EPS) as a light embankment is known, such as the EPS method. Resin foam blocks are stacked on a supporting ground to form a light-weight embankment layer of a predetermined height, and a concrete floor slab is placed thereon, and road structures such as roadbed and asphalt pavement are made as finishing work.

  When such a lightweight embankment structure is installed in a place where the groundwater level fluctuates, the resin foam block forms a lightweight embankment layer when the water level rises because the density of the resin foam block is smaller than the density of water. Body blocks may become unstable due to buoyancy. In order to avoid this, a lightweight embankment structure is provided with a buoyancy countermeasure structure.

  In Patent Document 1, a resin foam block having through holes in the vertical direction and the horizontal direction is arranged below the groundwater level, and a resin foam block without through holes is picked up on the resin foam block to form a lightweight embankment layer, Describes an embankment structure in which a road structure is formed. In this structure, since groundwater enters into the through hole of the resin foam block having the through hole arranged below the groundwater level, the buoyancy received by the lightweight embankment layer can be reduced. Patent Document 2 also describes a fill material made of resin foam in which a space portion is formed between protrusions, and even in a light weight fill structure using this, water is introduced into the fill body through the space portion. Since the buoyancy is small, the embankment material is described as being stable.

  Patent Document 3 and Patent Document 4 describe a structure having a space inside made of non-foamed synthetic resin or light metal, and describe that these can be used as a lightweight embankment.

Japanese Utility Model Publication No. 7-8434 Japanese Utility Model Publication No. 7-12431 Japanese Patent Laid-Open No. 11-36383 (FIG. 9) Japanese Patent Laying-Open No. 2002-339383 (FIG. 8)

  As described in Patent Documents 1 and 2, as a countermeasure for buoyancy of a lightweight embankment structure, by using a resin foam block having a space inside a part of or all of the lightweight embankment, resin foaming occurs when the water level rises. The buoyancy that the body block receives can be effectively reduced. However, since the material is a resin foam, the buoyancy reduction rate is limited to about 60%, and a sufficient buoyancy reduction effect may not be obtained depending on the installation location of the lightweight embankment structure.

  In the case of a structure having a space inside such as non-foamed synthetic resin or metal as described in Patent Documents 3 and 4, the volume of the vertical structure for supporting the load in the vertical direction Even if it is made small, the yield strength as a structure can be sufficiently secured, and as a result, the porosity can be increased to, for example, about 95%. Furthermore, since the specific gravity of the raw material is heavier than that of the resin foam, a larger buoyancy reduction rate can be expected for a lightweight embankment by using such a structure as a buoyancy countermeasure block.

  However, when many such blocks are laid on the support ground and arranged in multiple stages, the surface height of the uppermost block group tends to vary, and it is not easy to secure a horizontal plane. Covering it directly with earth and sand to create a banking structure does not cause major problems, but it is a construction site that is soft ground and requires high banking, that is, above the buoyancy countermeasure blocks. Furthermore, in construction sites where it is required to laminate resin foam blocks in multiple stages to form a lightweight embankment layer, the base side (that is, the upper surface of the topmost buoyancy countermeasure block group when arranged in multiple stages) Since the flatness cannot be ensured, there is a major inconvenience in construction that the posture and direction of the resin foam blocks stacked in multiple stages cannot be stabilized. In addition, the upper surface portion of the buoyancy countermeasure block may sink into the stacked resin foam block, which may make the posture of the resin foam block stacked further unstable.

  The present invention has been made in view of the above circumstances, and a resin is formed on a buoyancy countermeasure block group made of a material having a larger specific gravity than a resin foam, such as a non-foamed synthetic resin or a metal. It is an object of the present invention to provide a lightweight embankment structure having a buoyancy countermeasure structure in which foam blocks can be easily and stably stacked in a multistage manner to form a light embankment. It is another object of the present invention to provide a lightweight embankment structure having a buoyancy countermeasure structure that can be easily constructed even in construction sites that are soft ground and require high embankments.

  A lightweight embankment structure having a buoyancy countermeasure structure according to the present invention is a buoyancy countermeasure block group comprising a plurality of molded products having a water passage space between longitudinal structures using a material having a larger specific gravity than a resin foam. It is characterized by comprising at least a structure in which a leveling layer is formed thereon and a lightweight embankment layer formed of a resin foam block is formed thereon.

  In the present invention, the material of the molded product constituting the buoyancy countermeasure block group is optional on the condition that the specific gravity is larger than that of the resin foam and has the required strength against the longitudinal load. A metal or the like can be used. Among these, non-foamed synthetic resins are preferable from the viewpoints of moldability and strength. Examples of the resin material include polypropylene resin.

  There are no particular restrictions on the shape of the buoyancy countermeasure block molded product, and the shape and number of longitudinal structures and the shape of the water flow space provided that the upper and lower surfaces of the molded product as a whole are substantially parallel. The number, direction, etc. are arbitrary. The thing of the shape described in each above-mentioned patent document may be sufficient.

  In the buoyancy countermeasure block group, a plurality of the molded products may be arranged in one stage, or may be arranged in multiple stages. In the case where the molded product has a directional shape, it is preferable to arrange in multiple stages while changing the direction by 90 degrees from the viewpoint of securing the stability of stacking.

  In the present invention, the leveling layer is a generic term for layers that can absorb unevenness existing on the upper surface of the buoyancy countermeasure block group on the lower surface side, and can form a flat surface on the upper surface side. An example is a concrete layer or a mortar layer that is built on site on the upper surface of the buoyancy countermeasure block group. More specifically, a concrete floor slab that is constructed on site on a resin foam block laminated with a conventional lightweight embankment structure can be mentioned. The lower surface side of the concrete placed on site is integrated with the buoyancy countermeasure block group while absorbing the unevenness existing on the upper surface of the buoyancy countermeasure block group, and the upper surface side is a flat surface. In the case of a concrete layer or a mortar layer, it is preferable to form a vent in a part, so that when the water enters the water flow space of the buoyancy countermeasure block group due to the rise of the groundwater level, the air inside is surely Can be discharged.

  As another form of the leveling layer, a granular member such as crushed stone or paving sand is covered with a sheet. In this case, due to its own weight, the lower surface has a shape imitating the unevenness existing on the upper surface of the buoyancy countermeasure block group, and absorbs the unevenness, and the upper surface is mounted from a laminated resin foam block or the like. By the load, the shape follows the lower surface of the resin foam block, that is, a flat surface.

  In the light-weight embankment structure having the buoyancy countermeasure structure according to the present invention, the above-mentioned leveling layer can be arranged to obtain a flat surface as a foundation for stacking. Is also stable. Therefore, it is possible to easily perform construction even in a construction site where soft ground and high embankment are required.

  The lightweight embankment structure having a buoyancy countermeasure structure according to the present invention may be a structure in which all buoyancy countermeasure blocks are embedded in the ground, or may be a structure in which all are located above the ground surface. A structure in which only a part is buried in the ground may be used. Furthermore, it may be a double straight structure as a whole or a single straight structure. In any case, it is desirable that a water-permeable sheet such as a non-woven fabric is disposed around at least a portion embedded in the ground of the buoyancy countermeasure block group. Thereby, it is possible to prevent sediment and the like from entering the water passage space, and it is possible to avoid the reduction of the buoyancy reduction rate due to the narrow water passage space over a long period of time.

  In the lightweight embankment structure provided with the buoyancy countermeasure structure according to the present invention, the superstructure is arbitrary. A concrete floor slab and a road structure may be formed on the upper surface of the lightweight embankment layer, or simply embankment and a structure like a green space or ground may be formed thereon.

  According to the present invention, resin foam blocks can be easily and stably stacked in a multistage manner on a buoyancy countermeasure block group made of a material having a specific gravity greater than that of a resin foam to provide a lightweight embankment. . Therefore, it is possible to easily construct a light-weight embankment structure having a buoyancy countermeasure structure even in a construction site that is soft ground and requires high embankment.

  Hereinafter, the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a perspective view showing a state in which buoyancy countermeasure blocks used in a lightweight embankment structure according to the present invention are stacked in multiple stages to form a block group. FIG. 2 is a perspective view showing a concrete layer as an example of a leveling layer. 3-5 show in cross section different forms of the lightweight embankment according to the invention.

  In this example, the buoyancy countermeasure block 10 is a molded product of non-foamed synthetic resin, and has a continuous shape in which a large number of longitudinal structures 11 have a cross-sectional shape and a mountain shape. In the molded product, that is, the buoyancy countermeasure block 10, the upper surface and the lower surface as a whole are substantially parallel. The upper end edges of the adjacent longitudinal structures 11 are connected by an upper end face 12 having irregularities in the longitudinal direction, and the lower end edges have an opening into which a recessed area formed in the upper end face 12 can enter. It is continuous at the lower end surface 13. The space 14 existing between the vertical structures 11 is a lightweight embankment structure A after construction, and functions as a water passing space.

  As shown in FIG. 1, the buoyancy countermeasure blocks 10 are stacked in multiple stages (six stages in the figure) while changing the direction by 90 degrees to form one buoyancy countermeasure block group 20. In the lightweight embankment structure A according to the present invention, a large number of such buoyancy countermeasure block groups 20 are stacked in a required height over a required area. An embedding material 21 having a shape that fills the concave portion of the buoyancy countermeasure block 10 that forms the upper surface of the uppermost buoyancy countermeasure block group 20 stacked in multiple stages and that has a flat surface at the upper end is inserted. Sometimes. The buoyancy countermeasure block group 20 is the same as that described in Patent Document 3 described above.

  In constructing the lightweight embankment structure A according to the present invention, the ground surface is first excavated to a predetermined width and a predetermined depth, as shown in FIG. A water-permeable sheet 31 made of a material such as a nonwoven fabric is disposed on the excavation surface as necessary. A large number of buoyancy countermeasure blocks 10 shown in FIG. 1 are arranged in multiple stages on the support ground 32 on which the water-permeable sheet 31 is arranged to form a buoyancy countermeasure block group 20. In the example shown in FIG. 3, the buoyancy countermeasure block group 20 shown in FIG. 1 is used as one unit, and a large number are arranged in the width direction and the longitudinal direction, and are stacked in two stages in the vertical direction.

  When a large number of buoyancy countermeasure block groups 20 are arranged in the vertical and horizontal directions and in the height direction, especially when the ground surface is soft ground, the uppermost block surface is unlikely to be a uniform flat surface and becomes a non-land surface. Therefore, in the lightweight embankment structure A according to the present invention, the leveling layer 35 is formed thereon. In this example, the leveling layer 35 is a concrete layer as shown in FIG. The vent 36 can be omitted.

  In order to form the concrete layer 35, the upper surface of the stacked buoyancy countermeasure block group 20 is laid with a water-impervious sheet made of polyvinyl chloride, synthetic rubber or the like that functions as a lower mold, and if necessary, reinforcement is arranged. Moreover, after installing the mold for the vent 36 and the surrounding formwork, the concrete is poured. The placed concrete is integrated with the upper surface of the buoyancy countermeasure block group 20 on the lower surface side while acting to absorb unevenness existing on the upper surface of the buoyancy countermeasure block group 20. The upper surface side is a flat surface. After the concrete is hardened, the surrounding mold and the mold for the air vent 36 are removed, and a hole is made in the formed water-impervious sheet of the vent 36 or the part of the impermeable sheet is cut out. Thereby, as shown in FIG. 2, the concrete layer 35 in which the upper surface side became a flat surface is formed as a leveling layer.

  Thereafter, in the same manner as the conventional lightweight embankment structure is constructed, a column 38 for attaching the wall material 37 is erected on the foundation concrete 39, and a resin foam such as EPS is formed on the concrete layer (leveling layer) 35. The body blocks are stacked in multiple stages to form a lightweight embankment layer 40. The upper surface of the concrete layer (leveling layer) 35 that becomes the stacked substrate of the lightweight embankment layer 40 is a flat surface, and the resin foam blocks can be stacked easily and stably. Further, the upper surface portion of the buoyancy countermeasure block 10 does not sink into the stacked resin foam block.

  A concrete floor slab 41 is made on the light weight embankment layer 40, and a road structure made of ground-covered concrete 42, a roadbed 43, asphalt pavement 44, etc. is made thereon, and the light weight embankment structure according to the present invention. It becomes the body A.

  In the above-described lightweight embankment structure A, even if the groundwater may rise to the ground surface, the groundwater enters the water flow space of the buoyancy countermeasure block group 20, and the buoyancy countermeasure block 10 has a specific gravity higher than that of the resin foam. Therefore, the buoyancy countermeasure block group 20 hardly receives buoyancy or very little, if any, and the lightweight embankment layer 40 formed by the resin foam blocks stacked thereon is not suitable. It will never be stable. Further, the resin foam block is laminated on a concrete layer (leveling layer) 35 having a flat surface, and the laminated body is extremely stable. Also from this point, the lightweight embankment layer 40 is unstable. It will never be.

  Although not shown, the leveling layer 35 may be a mortar layer, and a sheet material such as a nonwoven fabric or a net made of resin fibers such as polypropylene fibers is placed on the upper surface of the buoyancy countermeasure block group 20, and a crushed stone is placed thereon. A leveling layer can also be formed by laying a granular member such as sand or sand to the required thickness and then covering the whole with a sheet material. By stacking the resin foam block on the leveling layer thus formed, the upper surface of the leveling layer can be easily flattened by the applied load, and thereafter the resin foam block can be stably stacked in multiple stages. Can do.

  FIG. 4 shows another embodiment of the lightweight embankment structure A according to the present invention. Here, it is a one-sided structure, but its construction structure and construction procedure are the same as those shown in FIG. It is substantially the same. Accordingly, the same members are denoted by the same reference numerals and description thereof is omitted. In this case, H steel is used as the support column 38 to counter the side pressure.

  FIG. 5 is the same as that shown in FIG. 3 in that it is a double straight structure, but differs in that the buoyancy countermeasure block group 20 is located above the ground surface. Such structures, such as road structures built close to rivers, are not usually immersed in water, but when the rivers increase, the water level rises to the riverbed, and some of the water is submerged. It is effective for road structures at places so that it is predicted to be immersed. Here, the same members as those shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

The perspective view which shows the state which piled up the buoyancy countermeasure block used with the lightweight embankment structure by this invention in multiple steps, and made it the block group. The perspective view which shows the concrete layer as an example of the leveling layer used with the lightweight embankment structure by this invention. Sectional drawing which shows the form of the lightweight banking structure by this invention. Sectional drawing which shows the other form of the lightweight banking structure by this invention. Sectional drawing which shows the further another form of the lightweight banking structure by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS A ... Lightweight embankment structure, 10 ... Buoyancy countermeasure block, 11 ... Longitudinal structure, 12 ... Upper end surface, 13 ... Lower end surface, 14 ... Space which functions as water flow space of a buoyancy countermeasure block, 20 ... Buoyancy countermeasure block group , 21 ... Embedded material, 31 ... Water-permeable sheet, 32 ... Support ground, 35 ... Leveling layer (concrete layer), 36 ... Vent, 37 ... Wall material, 38 ... Column, 39 ... Foundation concrete, 40 ... Lightweight embankment layer 41 ... Concrete floor slab, 42 ... Concrete concrete, 43 ... Subgrade, 44 ... Asphalt pavement

Claims (6)

A plurality of non-foamed synthetic resin molded article having a structure having a water passage space between the longitudinal structure using the specific gravity of the large non-foamed synthetic resin than the resin foam was placed on a support ground as buoyancy measures block group And at least a structure in which a leveling layer is formed thereon and a lightweight embankment layer is formed by a resin foam block. lightweight embankment structure with a buoyancy measures structure, characterized in that is. The lightweight embankment structure provided with the buoyancy countermeasure structure according to claim 1, wherein the leveling layer is a concrete layer or a mortar layer. The lightweight embankment structure provided with the buoyancy countermeasure structure according to claim 2 , wherein the concrete layer or the mortar layer has a ventilation hole in a part thereof. The light level embankment structure provided with the buoyancy countermeasure structure according to claim 1, wherein the leveling layer is formed by covering a granular member such as crushed stone or sand with a sheet. The buoyancy countermeasure block group is in a state of being embedded in the ground, and a water-permeable sheet is disposed around at least a portion of the buoyancy countermeasure block group embedded in the ground. lightweight embankment structure with a buoyancy measures structure according to any one of 1 to 4. The lightweight embankment structure provided with the buoyancy countermeasure structure according to any one of claims 1 to 5, wherein a concrete floor slab and a road structure are formed on an upper surface of the lightweight embankment layer.

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