JP2014237968A - Construction method of lightweight banking structure and lightweight banking structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discourage a retaining wall fixed to a post from being damaged by a pressure of the water accumulating in the space between the posts, relating to a lightweight banking structure in which foam body blocks are stacked.SOLUTION: In a lightweight banking structure, a retaining wall 21 made from a concrete panel or the like is fitted to a front surface side of a post 14 including an H-steel provided upright by a plurality of numbers on a foundation 11, and foam body blocks 35 made from styrene foam are stacked on the foundation on a rear surface side of the post 14. A resin foam material 41 such as hard polyurethane foam material is injected and foamed between the posts 14 between the retaining wall 21 and the foam body block 35, so that a foam body made from hard polyurethane foam body material, semi-hard urethane foam material, or the like, is packed between the posts 14 between a retaining wall 21 and the foam body block 35.

Description

  The present invention relates to a method for constructing a lightweight embankment structure in which a retaining wall is attached to the front surface side of a plurality of pillars erected on a base, and a foam block is laminated on the base on the back side of the pillar, and a lightweight embankment structure using the same.

  As shown in FIG. 5, for example, in a lightweight embankment structure adopted in the formation of road widening on a sloping land, formation of a bank on a flat land, etc., the front surface of a plurality of columns 53 erected at a predetermined interval on a base 51 of a construction site for lightweight embankment There is a structure in which a retaining wall 71 is attached to the side, and a foam block 75 made of foamed polystyrene or the like is laminated on the base 51 on the back side of the support column 53 (commonly known as EPS method). Reference numeral 76 is a blindfold plate, and 78 is a concrete floor board.

  FIG. 6 is a cross-sectional view showing a part on the retaining wall 71 side in the lightweight embankment structure of FIG. H steel is used for the column 53, and a plurality of retaining walls 71 are arranged in the lateral direction on the front surface of the front side flange 54, and a plurality of the retaining walls 71 are stacked upward and attached by attachment parts 57. The retaining wall 71 is made of a concrete panel or the like. The foam block 75 is laminated on the base 51 behind the rear flange 55 of the support column 53. Reference numeral 59 denotes a sealing material.

  Further, in the conventional lightweight embankment structure in which the foam blocks are laminated, the support columns 53 are present at a predetermined interval between the retaining wall 71 and the foam block 75, and a space 81 is formed between the adjacent support columns 53. The space 81 between the columns 53 is closed at the upper end by the blindfold plate 76, and a drainage facility is usually provided.

  However, in the conventional lightweight embankment structure in which the foam blocks are laminated, 53 between the support columns 71 and the foam block 75 between the retaining wall 71 and the foam block 75 due to some factors such as deterioration over time and clogging of a water pipe or the like. When water enters the space 81 and cannot be drained, as shown in FIG. 7, some retaining walls 71A may be damaged by water pressure. In this case, the damaged retaining wall 71A is removed. A new retaining wall had to be attached, and there was a problem that it took time to work and the repair cost increased. Moreover, the retaining wall may be damaged by water pressure even after replacement of the retaining wall.

JP-A-8-27819 JP-A-11-1000084

  This invention is made | formed in view of the said point, Comprising: In the lightweight banking structure which laminated | stacked the foam block, it aims at making it a lightweight banking structure where a retaining wall becomes difficult to break with water pressure.

  The invention of claim 1 is characterized in that a retaining wall is attached to the front side of a plurality of upright columns, a foam block is laminated on a base laid on a column embedding surface on the back side of the columns, The present invention relates to a construction method for a light-weight embankment structure, in which a two-component resin foam raw material is injected into a space corresponding to the thickness of the support column and foamed between the back side.

The invention of claim 2 is characterized in that, in claim 1, the two-component resin foam raw material forms a foam having a free foam density of 10 to 20 kg / m ^{3 made} of polyurethane resin.
The invention of claim 3 is characterized in that, in claim 1 or 2, the foam is an open cell structure.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, in order to inject and foam the two-component resin foam raw material, the thickness of the foam per layer is set to 70 cm or less a plurality of times. In addition, the layers are stacked up to the upper end of the gap by sequentially foaming, and then the entire upper end is covered with a blind plate from the front side to the back side of the support column.

  Invention of Claim 5 concerns on the lightweight banking structure constructed | assembled using the construction method of the lightweight banking structure as described in any one of the said Claims 1 to 4.

  According to the invention of claim 1, since the space between the support wall and the foam block is filled with foam formed between the support columns, water can accumulate between the support columns. It is possible to prevent the retaining wall from being damaged by the accumulated water pressure. In addition, even for light-weight embankment structures that have already been constructed, foaming is performed between the retaining wall and the foam block by injecting the foamed resin material between the retaining wall and the foam block. Since the body can be filled and the light weight embankment structure of the present invention can be obtained, the present invention can also be applied to repair of a light weight embankment structure that has been constructed.

Furthermore, according to the invention of claim 2, since the two-component resin foam raw material forming a foam having a free foam density of 10 to 20 kg / m ^{3 made} of polyurethane resin is injected and foamed, heat generated during foaming The amount can be reduced. The amount of the foam resin material that can be injected at a time can be made larger than when other foam resin materials are used, so that the foam layer that can be formed at a time can be made thicker. As a result, the required number of injections can be reduced, so that the construction efficiency increases and the number of man-hours can be shortened. The free foam density refers to the density when the polyurethane reaction mixture is freely foamed at room temperature and atmospheric pressure. In addition, the measurement of a density is based on JISK7222: 2005.

According to the invention of claim 3, since the foam is an open-cell structure, the amount of heat accumulated in the foam can be released during foaming, and the retaining wall and the foam block are damaged by heat. There is no.
Similarly, according to the invention of claim 4, by performing the process in multiple times with the thickness of the foam per layer being 70 cm or less, it is possible to release the amount of heat accumulated in the foam during foaming. Walls and foam blocks are not damaged by heat. Incidentally, the thickness of 70 cm or less is a thickness after curing related to one injection foaming, and thereafter, injection filling is repeated repeatedly. This value is determined according to the reaction time and injection amount of the polyurethane resin raw material at the construction site. Then, after the foam is laminated to the upper end of the gap, the upper end is covered with a blindfold plate from the front side to the back side of the support column, so that the water does not submerge, and the water pool caused by deterioration over time The retaining wall is not damaged by water pressure.

  According to the fifth aspect of the present invention, it is possible to obtain a light weight embankment structure in which water does not accumulate between the columns, and the retaining wall can be prevented from being damaged by the pressure of the accumulated water.

It is a longitudinal cross-sectional view which shows the time of injection | pouring of the foaming resin raw material in one Embodiment of this invention. It is a cross-sectional view of a part of the retaining wall side of FIG. It is a longitudinal cross-sectional view which shows after foam filling in one Embodiment of this invention. FIG. 4 is a partial cross-sectional view of the retaining wall side of FIG. 3. It is a longitudinal cross-sectional view which shows the conventional lightweight banking structure. It is a cross-sectional view of a part of the retaining wall side of FIG. It is a longitudinal cross-sectional view which shows the breakage of a retaining wall.

An embodiment of a lightweight embankment structure according to the present invention will be described by taking a paved road on a steep slope as an example.
The light weight embankment structure of the present invention has a retaining wall 21 attached to the front side of a plurality of columns 14 erected on the construction surface, as shown in the longitudinal sectional view shown in FIG. 1 and the transverse sectional view shown in FIG. A foam block 35 is laminated on the base 11 laid on the back-side support column embedding surface, and between the front side and the back side of the support column 14, the two-part liquid is formed in the gap 27 corresponding to the thickness of the support column 14. By injecting and foaming the resin foam raw material 41, construction is performed using a construction method of a lightweight embankment structure in which the foam 45 is filled as shown in the longitudinal sectional view shown in FIG. 3 and the transverse sectional view shown in FIG. It has been done.

  As shown in FIG. 1, a plurality of the pillars 14 are driven into the base 11 at the embankment construction site at a predetermined distance from the slope (slope) 12 at equal intervals. As shown in FIG. 2, H steel is used for the support 14, the flange on one side of the H steel faces the slope side, and the flange on the other side faces the valley side opposite to the slope. It is made to become the front side flange 17 which faces.

  The retaining wall 21 is attached to the front side of the support column 14, that is, the outer surface of the front side flange 17 of H steel. The retaining wall 21 is made of a concrete panel or the like, and the required number is arranged in the horizontal direction according to the size of the construction site, and is stacked up to near the upper end of the column 14. For attaching the retaining wall 21 to the support column 14, a known attachment component 31 used for attaching the panel can be used. The illustrated mounting part 31 is composed of a metal fitting, a bolt, and a nut. One end of the metal fitting is fixed to the back surface of the retaining wall 21 with a bolt and a nut, and the front side flange 17 of the column 14 is connected to the rear surface of the retaining wall 21 and the metal fitting. It consists of the structure pinched by one end side. The space between the front flange 17 of the support column 16 and the retaining wall 14 is sealed with a sealing material 23 made of rubber sponge or the like.

  The foam block 35 is made of a foamed material such as polystyrene foam in a rectangular parallelepiped shape, and is laminated to the base 11 between the rear flange 16 and the slope 12 of the support column 14 to the vicinity of the upper end of the support column 14. By stacking the foam blocks 35, a gap 27 is formed between the support walls 21 and the struts 14 between the foam blocks 35. A space between the foam block 35 and the slope 12 is filled with an embedding material 37 made of crushed stone or the like. A concrete floor board 49 is disposed on the uppermost layer of the foam block 35.

  The two-component resin foam raw material 41 is preferably a known hard polyurethane foam raw material or semi-rigid urethane foam raw material that forms a rigid polyurethane foam or a semi-rigid urethane foam by a reaction between a polyol and an isocyanate. The two-component resin foam raw material 41 is injected into the gap 27 between the columns 14 between the retaining wall 21 and the foam block 35 from the upper end side of the gap 27 by an injection device N such as a spray gun. The two-component resin foam raw material 41 injected into the gap 27 foams from the lower side in the gap 27, becomes a foam 45, and fills up to the upper end of the gap 27.

  When the amount of one-time injection increases and the size of the foam formed by one-time foaming increases, the two-component resin foam raw material 41 increases the amount of heat generated at the time of foaming. The foam block 35 in contact with the foam raw material 41 and in contact with the foam 45 formed from the two-component resin foam raw material 41 is damaged by the heat of the two-component resin foam raw material 41 and the foam 45. There is a fear. Further, when the gap 27 is narrow, the retaining wall 14 may be affected by the foaming pressure of the two-component resin foam raw material 41. In order to prevent the occurrence of these problems, the injection and foaming of the two-component resin foam raw material 41 into the gap 27 are performed in a plurality of times, and the foam 45 having a predetermined thickness is sequentially formed and foamed. It is preferable to laminate up to the upper end of.

In particular, in order to suppress an excessive increase in heat generation and foaming pressure of the two-component resin foam raw material 41, the thickness per layer of the foam 45 to be foamed is preferably 70 cm or less. Further, the two-component resin foam raw material 41 is preferably a rigid polyurethane foam raw material or a semi-rigid urethane foam raw material having a free foam density of 10 to 20 kg / m ^{3 in} order to suppress the calorific value. It becomes possible to increase the thickness of the foam layer that can be formed at one time by increasing the two-component resin foam raw material that can be injected at one time by using the above density range, compared to the case of using other foamed resin raw materials. As a result, construction efficiency increases and man-hours can be shortened. The upper surface of the uppermost foam 45 filled in the gap 27, that is, the upper end of the gap 27 is covered with a blindfold plate 48 from the front side to the back side of the column 14.

As an example of the rigid polyurethane foam raw material or the semi-rigid urethane foam raw material, BIP (BASF INOAC Polyurethane Co., Ltd.) foam light (registered trademark) HM-9007-2, free foam density: 10 kg / m ³ , closed cell ratio: 3.0%, water absorption: include 2.9g / 100cm ^2. The foam obtained from this raw material is a low-density open-cell foam using only water as a foaming agent.

  Thus, in the light weight embankment structure constructed by the light weight embankment method of the embodiment, the foam 45 formed by foaming between the struts 14 between the retaining wall 21 and the foam block 35. Therefore, water does not accumulate between the support columns 14 between the retaining wall 21 and the foam block 35, and the retaining wall 21 can be prevented from being damaged by the pressure of the accumulated water.

  In addition, the light weight embankment method of the present invention and the light weight embankment structure constructed using the light weight embankment method are not limited to the case of newly forming a light weight embankment, and an existing light weight embankment structure already formed using a foam block. It is a useful thing that can also be applied to repairs.

11 Base 12 Slope 14 Post 21 Retaining Wall 35 Foam Block 41 Foam Resin Raw Material 45 Foam

Claims (5)

  A retaining wall is attached to the front side of a plurality of upright columns, a foam block is stacked on a base laid on a column-buried surface on the back side of the column, and between the front side and the back side of the column, A construction method for a lightweight embankment structure in which a two-component resin foam raw material is injected into a space corresponding to the thickness of the support column and foamed. The construction method for a lightweight embankment structure according to claim 1, wherein the two-component resin foam raw material forms a foam having a free foam density of 10 to 20 kg / m ^{3 made} of polyurethane resin.   The construction method for a lightweight embankment structure according to claim 1 or 2, wherein the foam is an open-cell structure.   Injecting and foaming the two-component resin foam raw material, the thickness of the foam per layer was set to 70 cm or less and divided into a plurality of times, and the foam was sequentially formed and laminated to the upper end of the gap. The construction method for a lightweight embankment structure according to any one of claims 1 to 3, wherein the upper end is entirely covered with a blindfold plate from the front side to the back side of the support column.   The lightweight embankment structure constructed | assembled using the construction method of the lightweight embankment structure as described in any one of Claim 1 to 4.

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