JP5130563B2 - Lightweight retaining wall block and lightweight retaining wall structure using the same - Google Patents

Description

  The present invention relates to a retaining wall block and a retaining wall structure using the same, and more particularly to a lightweight retaining wall block mainly composed of a foamed resin body and a retaining wall structure using the same.

Conventionally, cutting or embankment has been performed when a road is created on a sloping land or when a residential land is created. In order to obtain the stable slope of the cut slope or the fill slope, considerable cut and fill are required, and in order to secure a flat surface for use, it is necessary to secure a considerable area of the stable slope portion around it. is there.

  In some cases, embankments are carried out in depressions such as flat land and paddy fields, and self-location boards higher than the surrounding ground are built, and specific use facilities such as roads, houses or parks are built there. Also in this case, a considerable amount of embankment and a sufficient occupied area (occupied width in the case of road construction) are required so that the ground built by embankment does not collapse.

  As another point of view, there is a need to raise the ground to build buildings as a countermeasure against ground inundation due to torrential rains, resulting river flooding or sea level rise, which may be caused by global warming. It is happening.

On the other hand, the slope is steeper than the stable slope, enabling road construction and residential land development, or occupying area (occupied when building roads and residential land by building a ground higher than the surrounding ground. Retaining walls are used for effective use of land, such as keeping the width to a necessary and sufficient amount. That is, various retaining walls are used in order to give independence to natural ground when embankment or cutting is performed. General examples of the retaining wall include a weight retaining wall, an inverted T-shaped retaining wall, and an L-shaped retaining wall. In particular, inverted T-shaped retaining walls and L-shaped retaining walls use less concrete than heavy-weight retaining walls of the same scale, but the embankment weight on the heel plate is also considered as its own weight. It is widely used from the viewpoint of a rational shape that can reduce the above.

  However, all of the conventional retaining walls represented by weight-type retaining walls, inverted T-shaped retaining walls, L-shaped retaining walls, etc. have their own weights (the self-weights on the left are inverted T-shaped retaining walls and L-shaped retaining walls). In the case of the wall, the weight including the embankment located on the heel plate is considerably large), so that the handling is not easy and the cost is high.

  In addition to the above problem of handling, the retaining wall has a problem that due to its own weight, a consolidation settlement phenomenon occurs in the ground where the retaining wall is constructed. That is, normally, the retaining wall is supported by the ground reaction force below the retaining wall. However, the ground cannot support the weight of the retaining wall due to changes in the ground shape over time, the effect of the load on the structure built above the retaining wall, or the inertial force due to the earthquake, etc. As a result, the ground is compressed and consolidated, and as a result, the balance between the weight of the retaining wall and the ground reaction force is lost, resulting in settlement problems such as uneven settlement and falling of the retaining wall. According to the occurrence of the consolidation settlement phenomenon of the ground, not only is the retaining wall collapsed, it is dangerous, but it also leads to the unsettled settlement of roads and houses that are structures on the ground that are maintained by the retaining wall. (Hereinafter, these problems are also simply referred to as “consolidation settlement problems”).

  In order to solve the above problems of handling and consolidation settlement, the weight of the retaining wall has been reduced, and a technique using a foamed resin body for the retaining wall structure has been developed. For example, as an example of the above technique, there is a polystyrene foam civil engineering method (EPS method) (for example, Non-Patent Document 1 below). As another example, the following Patent Document 1 is disclosed as a method for constructing a retaining wall by combining a concrete wall and a urethane foam layer.

  The EPS construction method is a construction method in which large foamed polystyrene blocks are stacked in the ground to replace soil and a lightweight foamed resin body. For example, in order to be used for stabilization of a slope, it faces a natural ground. A wall surface such as concrete is formed on the front surface, and a retaining wall is formed by stacking polystyrene foam blocks on the inside.

  Further, the retaining wall disclosed in Patent Document 1 is a space formed between a wall body and an inclined surface such as a natural ground located behind the wall body by constructing a wall body with concrete or the like in advance at a wall body construction place. Inside, the urethane foam stock solution is filled and foamed to form a urethane layer (hereinafter also referred to as “urethane-filled retaining wall”).

  In the retaining wall structure related to either the above-mentioned Styrofoam civil engineering method or the urethane-filled retaining wall, because the soil in the ground is replaced with a lightweight foamed resin body, the force acting on the ground located below as the weight of the retaining wall structure Has been reduced, so the problem of consolidation consolidation of the ground, which has been a problem in the past, has been improved. In particular, it is lighter than conventional heavy-weight retaining walls, inverted T-shaped retaining walls, and L-shaped retaining walls, making it easier to handle, reducing transportation costs and shortening the construction period. As a result, the cost can be reduced compared with the construction cost of the retaining wall structure using the conventional retaining wall.

"EPS construction method design and construction standards (draft)", edited by Styrofoam Civil Engineering Development Organization (issued in October 2007) JP-A-6-49853

However, in the above-mentioned Styrofoam civil engineering method or the method of Patent Document 1, although the weight of its own weight is reduced, the concrete wall portion on the front side of the retaining wall structure is very heavy, and the lightweight foamed resin body. It was difficult to balance the weight of the retaining wall structure itself. Therefore, the load is mainly concentrated on the concrete wall portion on the front side, and the ground reaction force is concentrated on the ground below the retaining wall structure. For this reason, the balance between the weight of the retaining wall structure and the ground reaction force collapses due to a slight change in the ground shape, the inertial force of the earthquake, or a change in the loading load above the retaining wall. There was a problem that it tilted or fell, rotated, or slid on the opposite side of the mountain side (hereinafter sometimes referred to as “the valley side”).

  The present invention has been made in view of the above problems, and aims to provide a lightweight retaining wall block and a lightweight retaining wall structure that are lightweight and can appropriately balance the load of the retaining wall structure. To do.

The present invention
(1) Retaining wall having substantially horizontal top and bottom surfaces, a back surface that is expected to face the natural ground side, a front surface that is expected to face the natural ground side, and two or more side surfaces other than the back surface and the front surface. The block is made mainly of a foamed resin body, the foamed resin body is provided with an uneven load adjusting concrete part, and the volume ratio of the foamed resin body and the uneven load adjusting concrete part is 70:30 to 95. 5 is a horizontal plane that includes the center of gravity of the foamed resin body and is substantially horizontal to the bottom surface and the top surface, and includes a center of gravity of the foamed resin body and is perpendicular to the horizontal plane and is front of the retaining wall block When the retaining wall block is divided into four divided areas with a vertical plane that divides the side and the back side, 50% or more of the concrete part for adjusting the unbalanced load is included in the divided area including the back surface and the bottom surface. That Lightweight for constructing the retaining wall block to a butterfly,
(2) The lightweight retaining wall block according to (1), wherein the uneven load adjusting concrete part is provided at a position exposed along the bottom surface from at least one side surface of the retaining wall block. ,
(3) In the concrete part for adjusting an offset load, one or more vertical holes extending in a substantially vertical direction from a surface exposed along a bottom surface of the retaining wall block are provided. The lightweight retaining wall block according to (2),
(4) An auxiliary adjustment concrete part is further provided above the offset load adjusting concrete part, and the weight of the auxiliary adjustment concrete part is equal to or less than the weight of the offset load adjusting concrete part. The lightweight retaining wall block according to any one of (1) to (3) above,
(5) A basic concrete layer provided directly or indirectly on the ground, a lightweight retaining wall block according to any one of (1) to (4) installed on the upper surface of the basic concrete layer, and the lightweight It is provided with an upper surface protective concrete layer for protecting the upper surface of the retaining wall block, and a front protective wall for protecting the front surface of the lightweight retaining wall block that is expected to face the natural ground side. Lightweight retaining wall structure,
(6) An anchor standing up in a substantially vertical direction from an upper surface of the foundation concrete layer is provided, and the anchor is inserted into a vertical hole provided in the concrete portion for adjusting the offset load. The lightweight retaining wall structure according to (5),
(7) One end of a horizontal force suppression work such as a geogrid is laid in the upper surface protective concrete layer as a connecting member between the upper surface protective concrete layer and the ground continuous therewith, and outside the upper surface protective concrete layer The lightweight retaining wall structure according to the above (5) or (6), wherein the horizontal force suppression work that is exposed to the ground is embedded and laid in the ground,
Is a summary.

Hereinafter, some terms used in the present invention will be defined.
In the present invention, the “retaining wall block” means one unit constituting the retaining wall structure, and the “lightweight retaining wall structure” of the present invention is constructed by continuously installing the retaining wall structure on the slope.

Further, in the present invention, the “natural mountain” means a mountain part having a slope, a hilly area, or a banking part formed by embankment or cutting on a flat land or depression.
“The back side that is expected to face the natural ground side and the front side that is expected to face the natural ground side” means that the surface side where the retaining wall structure is exposed when the retaining wall structure is constructed is the front surface. This means that the surface facing the ground and facing the natural mountain is the back. In the retaining wall block, the surface that faces the natural ground but does not face the front surface means a “side surface” of the retaining wall block.

Further, in the present invention, when “the foamed resin body is provided with the concrete part for adjusting the unbalanced load”, in addition to the aspect in which the concrete part for adjusting the unbalanced load is completely included in the foamed resin body, a part of the surface of the foamed resin body A portion of the portion for adjusting the unbalanced load is exposed, or a portion of the portion for adjusting the unbalanced load is protruded to the ground side from the side surface and / or the back surface of the foamed resin body. Is also included. That is, the foamed resin body and the offset load adjusting concrete part include a horizontal plane that includes the center of gravity of the foamed resin body and is substantially horizontal to the bottom surface and the top surface, and includes a center of gravity of the foamed resin body and is perpendicular to the horizontal plane. In the case where the retaining wall block is divided into four divided areas by the vertical surface that divides the front side and the rear side of the retaining wall block, 50% or more of the concrete part for adjusting the unbalanced load is It is important that the relationship is included in the divided region including the bottom surface, and the remaining load adjusting concrete of less than 50% not included in the divided region including the back surface and the bottom surface has the back surface and the bottom surface. It may exist in divided areas other than the divided areas to be included or on the ground side.

The lightweight retaining wall block of the present invention is mainly composed of a foamed resin body, is lightened by its own weight, is easy to handle, has a conventional weight-type retaining wall, an inverted T-shaped retaining wall, Compared to the L-shaped retaining wall, the transportation cost and the construction cost due to the shortening of the retaining wall structure construction period can be kept low.

In addition to this, the lightweight retaining wall block of the present invention is self-supporting due to the shape having a substantially horizontal upper surface and bottom surface, and 50% is included in the lower position on the back side of the foamed resin body as the main component. As such, an offset load adjusting concrete part is provided.

Therefore, when the retaining wall structure is constructed using the lightweight retaining wall block of the present invention, there is no possibility that the problem of consolidation settlement of the ground occurs due to the weight reduction. In addition, the presence of the above-described concrete for adjusting the offset load makes it possible to increase the necessary amount of weight and to achieve a good load balance of the entire retaining wall structure. For this reason, the problem of tilting, overturning and sliding of the retaining wall due to horizontal earth pressure, which was a problem in the EPS construction method and urethane-filled retaining wall, and the problem of ground collapse associated therewith are dramatically improved. It was.

That is, the lightweight retaining wall structure of the present invention is provided with a front protective concrete wall that protects the front surface of the lightweight retaining wall block. It is installed at a position near the lower back of the lightweight retaining wall block. At this time, considering the load applied to the ground below the retaining wall structure due to the load on the front protective concrete wall or the load of the structure to be built above the lightweight retaining wall structure, the load on the entire retaining wall structure In order to adjust the deviation of the load, the weight of the concrete part for adjusting the offset load can be determined. Even if it is a lightweight retaining wall block of the present invention that is lighter than the conventional retaining wall, the retaining wall is inclined to the valley side due to the inertia force due to the occurrence of an earthquake and the horizontal earth pressure applied to the retaining wall, It is possible to satisfactorily prevent falling and sliding.

In general, horizontal retaining pressure is constantly applied to the retaining wall from the ground side, and depending on the properties of the ground where the retaining wall structure is provided and the buildings provided on the ground, the weight of the retaining wall is reduced. In such a case, the horizontal earth pressure cannot be withstood and the retaining wall may be pushed out in the valley side direction. On the other hand, if the retaining wall structure of the present invention of the aspect in which the anchor is provided on the upper surface of the foundation concrete layer and the anchor is inserted into a vertical hole provided in the retaining wall to construct the retaining wall structure, Even if the block for use is light, it is supported by the anchor, so that sufficient resistance can be given to the extrusion in the valley direction by horizontal earth pressure.

In order to more fully solve the problem that the retaining wall structure tilts, falls and slides toward the front side of the lightweight retaining wall block due to horizontal earth pressure, a connecting member such as a geogrid in the top protective concrete layer The retaining wall structure of the present invention connects the upper surface protective concrete layer and the ground continuous therewith by laying one end of the upper surface and embedding the connecting member exposed outside the upper surface protective concrete layer in the ground. The aspect is effective.

  In addition, the lightweight retaining wall structure of the present invention is constructed using the lightweight retaining wall block of the present invention mainly composed of a lightweight foamed resin body, but even when this lightweight retaining wall structure is submerged. The concrete part for adjusting the unbalanced load or the concrete part for adjusting the auxiliary load plays the role of a weight, and the lifting of the lightweight retaining wall structure can be prevented well. This lifting restraining effect is further increased by implementing horizontal restraining work such as anchors or geogrids in the present invention.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings. In the following description, the lightweight retaining wall block of the present invention may be simply referred to as “retaining wall block”. Similarly, the lightweight retaining wall structure of the present invention may be simply referred to as “retaining wall structure”. FIG. 1 (1A) is a perspective view of a retaining wall block 1 showing an embodiment of the retaining wall block of the present invention. The retaining wall block 1 includes a foamed resin body 2, an uneven load adjusting concrete part 3, and an auxiliary adjusting concrete part 4. The shape is a hexahedron composed of a substantially horizontal top surface 11 and bottom surface 12, a substantially horizontal front surface 16 and a back surface 15, and substantially horizontal side surfaces 13 and 14. Further, a slip prevention preventing rod insertion hole 5 is provided in each of the side surfaces of the uneven load adjusting concrete part 3 and the auxiliary adjusting concrete part 4. The front surface 16 is a surface that is planned to face the valley side when the retaining wall block 1 constructs the retaining wall structure, while the back surface 15 is scheduled to face the natural ground side. It is a surface. Further, the side surface 13 and the side surface 14 are surfaces that are expected to come into contact with other adjacent retaining wall blocks when the retaining wall structure is constructed.

  Moreover, the top view observed from the bottom face 12 side of the block 1 for retaining walls is shown in FIG. As is apparent from FIG. 2, three holes are provided in the bottom surface of the uneven load adjusting concrete portion 3 exposed along the bottom surface 12. These holes are vertical holes 6 extending in the vertical direction from the bottom surface of the offset load adjusting concrete part 3 in the offset load adjusting concrete part 3, and an anchor described later is scheduled to be inserted.

  FIG. 3 is a cross-sectional view of a retaining wall structure 31 showing an embodiment of the retaining wall structure of the present invention constructed on the slope using a plurality of retaining wall blocks 1. In the figure, GL1 indicates the ground level on the valley side, and GL2 indicates the ground level on the natural ground side. The retaining wall block and the retaining wall structure constructed using the same according to the present invention are not only used on the slope, but also a substantially horizontal land or depression such as a raised retaining wall structure or a retaining retaining wall structure. It can also be used for a retaining wall structure that is constructed to build a natural ground and to provide residential land and roads at a higher position than the surrounding ground.

  In order to construct the retaining wall structure 31, first, it is necessary to provide a horizontal ground for constructing the retaining wall structure on the slope, and to construct the basic structure of the retaining wall structure here. In the basic structure shown in FIG. 3, a civil engineering sheet 32 is laid, then crushed stone 33 is laid, and further sand is laid to form a sand layer 34. A light filter 35 is laid as a drainage facility on the upper surface of the sand layer 34. It is constructed by placing the drainage facility below the structure 31 and finally hitting concrete for forming the foundation concrete layer 36. Further, when the foundation concrete layer 36 is formed, a plurality of anchors 43 extending in a substantially vertical direction from the upper surface of the foundation concrete layer are provided. The installation position of the anchor 43 is set in accordance with the position of the vertical hole 6 of the retaining wall block 1 which is installed on the upper surface of the foundation concrete layer 36 in a later process. However, the above-mentioned foundation structure is only one embodiment of the retaining wall structure of the present invention, except that the foundation concrete layer 36 in contact with the bottom surface of the retaining wall block 1 is an essential constituent requirement. It is possible to appropriately design the base portion of the retaining wall structure 31 by taking in various elements that have been practiced in the past. FIG. 3 shows a mode in which the retaining wall blocks 1 are arranged in a horizontal row on the foundation concrete layer 36. However, the retaining wall structure of the present invention is not limited to this. Retaining wall structures may be constructed by overlapping blocks for use.

  After constructing the foundation structure, the retaining wall block 1 is continuously installed on the foundation concrete layer 36 such that the plurality of retaining wall blocks 1 are in contact with each other. At this time, after the concrete is cast to form the foundation concrete layer 36, the retaining wall block 1 is placed on the upper surface of the foundation concrete layer 36 before the concrete is completely hardened. This is preferable because the bottom surface of the block 1 and the top surface of the foundation concrete layer 36 can be closely bonded. When the retaining wall block 1 is placed on the upper surface of the foundation concrete layer 36, the anchor 43 provided on the foundation concrete layer 36 is provided on the concrete part 3 for adjusting the unbalanced load of the retaining wall block 1. It is inserted into the vertical hole 6. In order to further enhance the effect of preventing misalignment, as shown in FIG. 3, a further anchor 43 ′ separate from the anchor 43 is provided on the surface of the foundation concrete layer 36 in contact with the bottom surface of the foamed resin body 2. When installing the wall block 1 on the foundation concrete layer 36, the anchor 43 ′ may be inserted so as to pierce the foamed resin body 2.

  In order to prevent the installation position of each retaining wall block 1 from shifting in the completed retaining wall structure, when installing a plurality of retaining wall blocks 1 in contact with each other, The anti-slip bar 42 can be inserted into the anti-slip bar insertion hole 5 provided on the side of the wall block 1. A state in which the misalignment prevention rod 42 is inserted into the misalignment prevention rod insertion hole 5 is shown in FIG. 4 is a cross-sectional view taken along the line XX in a state in which the anti-slip bar 42 is inserted into the anti-slip bar insertion hole 5 of the retaining wall structure 31 shown in FIG.

  As is clear from FIG. 4, the plurality of retaining wall blocks 1 placed on the foundation concrete layer 36 are in contact with each other at the side surface 13 and the side surface 14. And the position of the opening part of the anti-slip | rod prevention rod insertion hole 5 each provided in the concrete part 3 and the auxiliary adjustment concrete part 4 for the offset load adjustment in the retaining wall block 1 substantially corresponds, and the anti-slip bar which faces each other A slip prevention rod 42 is inserted into a horizontally long space formed in the insertion hole 5. The installation of the misalignment prevention rod 42 is not an essential configuration in the retaining wall structure of the present invention, but the portions of the retaining wall blocks 1 constituting the retaining wall structure 31 constructed by providing the misalignment prevention rod. Is effectively prevented from slipping and falling.

  Further, in the retaining wall structure 31, a front protective wall 37 is provided so as to cover the front surface 16 side so that the front surface 16 of the retaining wall block 1 placed on the upper surface of the foundation concrete layer 36 is not exposed. Further, a drainage plate 28 is provided on the back surface 15 side of the retaining wall block 1 as a drainage facility for improving drainage of the ground. Finally, an upper surface protective concrete layer 39 is provided to cover the upper surface 11 of the retaining wall block 1, and the retaining wall structure 31 is completed. When the concrete is cast to form the upper surface protective concrete layer 39, a horizontal force suppressing work such as a geogrid 44 can be laid so as to be partially embedded in the upper surface protective concrete layer 39. The exposed portion of the geogrid 44 is embedded in the ground when embankment is performed on the mountain side of the retaining wall structure 31. By connecting the upper surface protective concrete layer 39 and the ground by the geogrid 44, the retaining wall structure can be prevented from being inclined and falling down to the valley side surface. In addition, the fence 40 is provided in the upper surface of the retaining wall structure 31 as one embodiment.

  Below, the detail is demonstrated for every component about the retaining wall block 1 of this invention, and the retaining wall structure 31 constructed | assembled using this.

(About foamed resin body 2)
The foamed resin body 2 that is the main body of the retaining wall block 1 includes an upper side that constitutes the back surface 15 in order to secure a space for providing a concrete portion 3 for adjusting an offset load and a concrete portion 4 for auxiliary adjustment, which will be described later. Each of the lower sides is cut out by a desired amount so that the cut-out cross section has an L shape with an angle of approximately 90 degrees. In the foamed resin body 2, the space for filling the concrete and providing the concrete portion 3 for adjusting the unbalanced load and the concrete portion 4 for auxiliary adjustment is formed by the method of cutting the foamed resin body 2 as described above. However, it may be formed in a desired shape in advance by, for example, in-mold foaming, or may be formed by pulling out any part of the hexahedron.

The size of the foamed resin body 2 used in the present invention can be appropriately determined according to the scale of the retaining wall block formed using the foamed resin body 2. However, when it is desired to be able to carry and install by human power, it is desirable that the vertical dimension is about 0.5 m to 2 m, the horizontal dimension is 0.5 m to 2 m, and the width dimension is about 0.5 m to 2 m.
In addition, regarding the shape of the retaining wall block 1 of the present invention comprising the foamed resin body 2 and the offset load adjusting concrete part 3 and further the auxiliary adjusting concrete part 4, the opposing surface shown in FIG. For example, a trapezoidal shape in which the front surface and the back surface have an inclination angle, a trapezoidal shape in which the side surface is inclined, or an octahedron having a hexagonal cross section may be used.

As the foamed resin material constituting the foamed resin body 2, a styrene resin material is desirable. Examples of the styrene resin material include a styrene homopolymer resin, a styrene copolymer resin produced from styrene and other monomers, and the like. The foamed resin board 2 is obtained by foaming the styrene resin by a known foaming means. The expansion ratio of the foamed resin body used can be appropriately determined in consideration of the ground for constructing the retaining wall structure and the weight of the building to be built on the retaining wall structure. It is desirable that the expansion ratio is about 40 to 80 times.

(Concrete load adjustment concrete part)
When the retaining wall structure is constructed using the retaining wall block 1, the uneven load adjusting concrete part 3 adjusts the load balance with respect to the ground located below the retaining wall structure, and increases the self-weight to some extent. It is a part provided for this purpose.

The concrete part 3 for adjusting the unbalanced load takes into account the weight of the front protective wall 37 and the weight of the structure to be built above the retaining wall structure (the fence 40 in FIG. 3) in the planned retaining wall structure. This is a part for balancing the load of the retaining wall structure. Therefore, the volume is determined in consideration of the balance of the weight. However, in order to be able to carry and install the retaining wall block manually, the weight is preferably 10 kg or more and 100 kg or less per 1 m ^{3 of the} foamed resin body, more preferably 10 kg or more and 20 kg or less. preferable. In addition, when providing the concrete part for auxiliary adjustment mentioned later, it is preferable that it is in the range of the said weight in the sum total of the weight of the concrete part for offset load adjustment, and the weight of the concrete part for auxiliary adjustment.

As shown in FIG. 1 (1B), the uneven load adjusting concrete portion 3 is divided into four parts by a horizontal plane indicated by a dotted line B including a center of gravity A of the foamed resin body 2 and a vertical plane indicated by a dotted line C. In the foamed resin body 2, 100% is contained in the divided region including the back surface 15 and the bottom surface 12. Thus, a horizontal plane that includes the center of gravity of the foamed resin body and is substantially horizontal to the bottom surface and the top surface, and a front surface side of the retaining wall block that includes the center of gravity of the foamed resin body and is perpendicular to the horizontal plane. When the retaining wall block is divided into four divided areas with the vertical plane that divides the back side, 50% or more of the concrete part for adjusting the offset load is included in the divided area including the back and bottom surfaces. By this, it is ensured that the center of gravity of the retaining wall block exists on the back side and below. As a result, the retaining wall block balances the load of the retaining wall structure, makes the retaining wall block sufficiently self-supporting, and can effectively prevent the retaining wall structure from tilting or falling over the Tanigawa surface. It can be done.

1 (1A) has a side portion constituting the bottom surface 12 of the foamed resin body 2 and one side constituting the upper surface 11 in a position parallel to the above side. Since it is provided in the notch part formed by notching so that the angle is approximately 90 degrees, a part thereof is exposed along the back surface 15, bottom surface 12, and side surfaces 13 and 14 of the foamed resin body 2. ing. However, if the condition that 50% or more is included in the divided region including the back surface and the bottom surface of the foamed resin body as described above, the partial load adjusting concrete part is completely enclosed in the foamed resin body. Also good.

That is, as in the above-described aspect, the aspect in which a part of the concrete for adjusting the unbalanced load is exposed along at least a part of the back surface, the bottom surface, or the side surface of the foamed resin body is particularly easy in the molding process of the unloading load concrete. It has the merit in that it is. That is, the foamed resin body is appropriately cut out or pulled out, and the foamed resin body is placed on a horizontal surface so that the cutout portion or the cutout portion is located above, and if necessary, a mold is provided, and the concrete is The concrete part for adjusting the offset load can be formed by a simple method of pouring. Therefore, from the viewpoint of ease of formation, the aspect provided in a position where a portion of the concrete part for adjusting the unbalanced load is exposed along the back surface of the foamed resin body, rather than being completely contained within the foamed resin body. desirable.
In addition, when providing a foamed resin body in the concrete part for uneven load adjustment, you may make the coupling | bonding of the contact surface between both stronger by using adhesives, such as a polymer cement mortar.

As described above, the bottom surface of the retaining wall block 1 shown in FIG. 1 is provided with a plurality of vertical holes 6 extending in the substantially vertical direction from the surface of the uneven load adjusting concrete portion 3. The vertical hole 6 is intended to be inserted with an anchor provided on the upper surface of the foundation concrete layer on which the retaining wall block 1 is placed or the foamed resin portion when the retaining wall structure described later is constructed. Depending on the state of the slope where the retaining wall structure is constructed and the type of building constructed above the retaining wall structure, vertical holes are omitted in the concrete part for adjusting the unbalanced load. It is possible to omit supporting the concrete part for adjusting ligation with an anchor.

(About concrete part for auxiliary adjustment)
Above the uneven load adjusting concrete portion 3 shown in FIG. 1 (1A), an auxiliary adjusting concrete portion 4 having substantially the same shape and weight as the uneven load adjusting concrete portion 3 is provided. A part of the auxiliary adjustment concrete part 4 is formed at a position where the part is exposed to the back surface 15, the top surface 11, and the side surfaces 13 and 14 of the foamed resin body 2.

The auxiliary adjusting concrete part 4 is an auxiliary part formed in the retaining wall block 1 of the present invention when the load balance is not desirably adjusted by the offset load adjusting concrete part 3 alone. Therefore, it is not an essential component in the retaining wall block of the present invention, and is omitted as appropriate when the load of the retaining wall structure is sufficiently adjusted only by the concrete part for adjusting the offset load. Moreover, the concrete part 4 for auxiliary adjustment and the foamed resin body 2 can be combined by the same method as the method of combining the concrete part for adjusting the unbalanced load and the foamed resin body.

The specific position and weight of the auxiliary adjustment concrete part 4 are determined within a range necessary for adjusting the load and the like of the retaining wall structure 31 by compensating for the balance adjustment of the uneven load adjustment concrete part 3. The However, it should be avoided that the design exceeds the weight of the concrete part 3 for adjusting the unbalanced load. This is because if the concrete part exceeding the weight of the concrete part 3 for adjusting the unbalanced load is installed above the concrete part 3 for adjusting the unbalanced load, the center of gravity of the retaining wall block 1 becomes high, This is because there is a possibility of promoting the inclination of the block 1 to the valley side or the mountain side and the fall. Further, from the viewpoint of ease of forming the retaining wall structure, it is provided at a position where a part of the concrete part for auxiliary adjustment is exposed along the back surface of the foamed resin body, rather than being completely enclosed in the foamed resin body. What is more desirable is the same as the above-described concrete part for adjusting the offset load.

(About vertical holes and anchors)
The vertical hole 6 and the anchor 43 are provided to support the foundation concrete layer 36 and the concrete part 3 for adjusting the offset load. Thus, in the retaining wall structure 31 constructed | assembled using the lightweight retaining wall block 1 mainly formed by a foamed resin body by supporting with an anchor member, this lightweight retaining wall block 1 is horizontal soil. It is possible to satisfactorily prevent the pressure from being pushed to the sloped valley side. In particular, when an inertial force is applied to the soft ground or the like when an earthquake occurs, the foundation concrete layer 36 and the retaining wall block 1 are separated from each other, and only the lightweight retaining wall block 1 is seen from the slope side. In consideration of the possibility of being pushed out toward the slope valley side, it is desirable to provide a structure for inserting the anchor 43 into the vertical hole 6. In addition, as shown in FIG. 3, an additional anchor 43 ′ different from the anchor 43 may optionally be provided on the foundation concrete layer 36 and inserted directly into the lower surface of the foamed resin body 2. In FIG. 3, the anchors 43 and 43 ′ are embedded in the foundation concrete layer 36 at the bottom and the bottom surface is at a depth located on the top surface of the crushed stone 33, but the installation of the anchor is not limited to this. The anchor extends to a ground portion located below the foundation concrete layer 36, and the lower end of the anchor may be embedded in the ground.

  The size of the vertical hole 6 is determined by the shape into which the anchor 43 can be inserted. As the vertical hole 6, a hole opened on the exposed surface of the uneven load adjusting concrete part 3 exposed along the bottom surface 12 of the retaining wall block 1 when forming the uneven load adjusting concrete part 3 is formed. May be provided. In addition, when forming the offset load adjusting concrete part 3, an anchor insertion case opened on the exposed surface of the offset load adjusting concrete part 3 exposed along the bottom surface 12 of the retaining wall block 1 is used. It may be embedded in site 3.

(About the misalignment prevention rod insertion hole and misalignment prevention rod)
The retaining wall insertion block 5 is provided with an offset preventing rod insertion hole 5 on the exposed surface of the unbalanced load adjusting concrete part 3 and / or the auxiliary adjusting concrete part 4 exposed on the side surfaces 13 and 14 of the retaining wall block 1. When the side surfaces of one of the two are brought into contact with each other, the anti-slip bar 42 can be inserted into a horizontally long hole formed by two adjacent anti-slip bar insertion holes 5.

  The misalignment prevention rod insertion hole 5 can be formed to an appropriate length and diameter in accordance with the misalignment prevention rod 42 to be inserted. FIG. 4 shows an example in which the anti-slip bar insertion holes 5 that do not communicate with each other are formed on both side surfaces of one retaining wall block 1. However, the anti-slip bar insertion holes 5 provided on both side surfaces of one retaining wall block 1 do not need to be provided as holes that open from the beginning to the side surface of the retaining wall block as described above. For example, as shown in FIG. 1, the side portion of the foamed resin body and the concrete portion for adjusting the unbalanced load exposed along the back surface and / or the side surface of the foamed resin body and the concrete portion for auxiliary adjustment exposed along the back surface and the top surface If it is an aspect of the retaining wall block of the present invention, the diameter of the misalignment prevention rod is larger than the back side or upper surface side of the uneven load adjusting concrete part and / or the auxiliary adjusting concrete part. , And a groove that extends to a position where the anti-slip bar is scheduled to be installed, and the groove that communicates between adjacent retaining wall blocks after the retaining wall block is installed on the foundation concrete A misalignment prevention rod may be installed by installing one misalignment prevention rod over the portion and then embedding the groove with mortar or the like. Therefore, in such a mode, the groove corresponds to the slip prevention preventing rod insertion hole in the present invention.

The above-described misalignment prevention rod insertion holes and misalignment prevention rods are not indispensable constituent elements in the present invention, but by using them, a plurality of them are arranged on the upper surface of the foundation concrete layer 36 by horizontal earth pressure applied to the retaining wall structure. The retaining wall structure 31 can be applied with a force that resists the positions of the retaining wall blocks 1 to be shifted from each other.

(About foundation concrete layer)
As the foundation concrete layer 36, a conventionally used concrete material can be appropriately selected and used. The thickness is not particularly limited, but it is desirable that the thickness is about 2 to 15 cm from the viewpoint of strength and cost.

(About the front protection wall)
The front protective wall 37 is for preventing the foamed resin body 2 from being exposed and protecting the retaining wall block. Generally, it is composed of a concrete wall having a thickness of about 5 to 15 cm, but is not limited to this. For example, a shotcrete wall, mortar, corrugated sheet, or the like may be used.

(About drain plate)
The drainage plate 28 is provided to improve drainage on the back side of the retaining wall structure 31 and is an example of a drainage facility provided between the retaining wall structure 31 and the ground. As the drainage plate 28, for example, a foamed foamed resin shape for drainage disclosed in JP-A-2005-30079 can be provided along the back surface of the retaining wall structure 31. The foamed resin molded article for drainage has a plurality of kerfs intersecting longitudinally and laterally on the back surface of a foamed resin plate having an appropriate thickness and rigidity, and preferably covers a water-permeable sheet. Therefore, the kerf portion is secured as a drainage channel. However, in the present invention, the drain plate 28 is not an essential component. In the ground with good drainage, it may not always be necessary to provide a drainage facility between the ground and the retaining wall structure 31. In addition to the installation of the drainage plate 28, a drainage facility such as the formation of a gravel layer between the retaining wall structure 31 and the ground can be appropriately selected as a drainage facility conventionally provided in the ground. Can be used.

(About the top protective concrete layer)
The upper surface protective concrete layer 39 is provided to protect the upper surface of the retaining wall block 1. Generally, it may be a concrete layer having a thickness of about 5 to 15 cm. After the retaining wall block 1 is installed on the upper surface of the foundation concrete layer 36, the retaining wall block 1 is provided so as to cover the upper surface of the retaining wall block 1.

(About horizontal force suppression work such as Geogrid)
Further, when forming the upper surface protective concrete layer 39, the front protective wall 37 and the ground continuous therewith are used by using a horizontal force deterrent made of a net-like special plastic member generally called a geogrid 44. You may connect. The geogrid 44 is generally used by reinforcing the ground by covering the ground surface requiring reinforcement. Examples of commercially available products of Geogrid 44 include, but are not limited to, the embankment reinforcement material Tensor (registered trademark) of Mitsubishi Petrochemical Co., Ltd., and the like. However, as shown in FIG. 3, by laying the upper surface protective concrete layer 39 and embedded in the ground continuous therewith, the concrete constituting the upper surface protective concrete layer 39 and the earth and sand in the ground are in a plastic mesh. It is possible to increase the friction force. And as a result, since the upper surface protection concrete layer 39 and the ground are strongly connected, it is possible to satisfactorily prevent the retaining wall structure 31 from being inclined or toppled by the horizontal earth pressure. In addition, examples of the horizontal force suppression work other than the geogrid 44 include a lock bolt.

(1A) is a schematic perspective view showing an embodiment of the retaining wall block of the present invention, and (1B) is divided into four regions by two planes orthogonal to the retaining wall block of the present invention shown in 1A. It is explanatory drawing which shows having performed. It is the schematic plan view which observed the block for retaining walls shown in FIG. 1 from the bottom face side. It is a schematic sectional drawing which shows one Embodiment of the retaining wall structure of this invention. It is XX sectional drawing of the retaining wall structure shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Retaining wall block 2 Foamed resin body 3 Uneven load adjustment concrete part 4 Auxiliary adjustment concrete part 5 Misalignment prevention rod insertion hole 6 Vertical hole 11 Upper surface 12 Bottom surface 13, 14 Side surface 15 Rear surface 16 Front surface
28 Drain plate 31 Retaining wall structure 35 Light filter 36 Basic concrete layer 37 Front protective wall 39 Upper surface protective concrete layer 42 Anti-slip bar 43, 43 'Anchor 44 Geogrid A Center of gravity B Horizontal line Dotted line D Vertical line

Claims (7)

A retaining wall block having substantially horizontal upper and lower surfaces, a rear surface that is expected to face the natural ground side, a front surface that is expected to face the natural ground side, and two or more side surfaces other than the rear surface and the front surface. There,
The foamed resin body is a main component, the foamed resin body is provided with an uneven load adjusting concrete part, and the volume ratio of the foamed resin body and the uneven load adjusting concrete part is 70:30 to 95: 5,
A horizontal plane that includes the center of gravity of the foamed resin body and that is substantially horizontal to the bottom surface and the top surface; and a front surface side and a rear surface side of the retaining wall block that includes the center of gravity of the foamed resin body and is perpendicular to the horizontal plane. When the retaining wall block is divided into four divided areas with a vertical plane that divides the area, 50% or more of the concrete part for adjusting the offset load is included in the divided area including the back surface and the bottom surface. A lightweight retaining wall block. 2. The lightweight retaining wall block according to claim 1, wherein the uneven load adjusting concrete part is provided at a position exposed along the bottom surface from at least one side surface of the retaining wall block. 3. 3. The one or more vertical holes extending in a substantially vertical direction from a surface exposed along the bottom surface of the retaining wall block in the concrete part for adjusting the offset load, are provided. Lightweight retaining wall block as described. An auxiliary adjustment concrete part is further provided above the uneven load adjustment concrete part, and the weight of the auxiliary adjustment concrete part is equal to or less than the weight of the uneven load adjustment concrete part. The lightweight retaining wall block according to any one of claims 1 to 3. A foundation concrete layer provided directly or indirectly on the ground; and
The lightweight retaining wall block according to any one of claims 1 to 4, which is installed on the upper surface of the foundation concrete layer,
An upper surface protective concrete layer for protecting the upper surface of the lightweight retaining wall block;
A front protective wall for protecting the front surface of the lightweight retaining wall block that is scheduled to face the natural mountain side;
A lightweight retaining wall structure characterized by comprising: 6. An anchor standing in a substantially vertical direction from the upper surface of the foundation concrete layer is provided, and the anchor is inserted into a vertical hole provided in the concrete part for adjusting the offset load. Lightweight retaining wall structure as described. As a connecting member between the upper surface protective concrete layer and the ground continuous to it,
One end of horizontal force restraining work such as geogrid is laid in the upper surface protective concrete layer, and the horizontal force restraining work exposed outside the upper surface protective concrete layer is embedded and laid in the ground The lightweight retaining wall structure according to claim 5 or 6.

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