JP3777321B2 - Lightweight embankment construction - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a light-weight embankment method, for example, a structure using a light-weight embankment material such as an EPS method, and particularly to the structure of the outer earth retaining wall.
[0002]
[Prior art]
As one of the embankment methods on soft ground or landslide land, a lightweight embankment method using a light embankment material such as an EPS method or a urethane method is known (see Japanese Patent Application Laid-Open No. 11-172680, etc.). This construction method is widely used in various civil engineering works because it exhibits excellent effects in terms of cost reduction for ground improvement, shortening the construction period, and improving earthquake resistance. FIG. 8 is a cross-sectional view of a road as an example of a structure constructed by the EPS method, and a foam block (EPS block) 10 is used as a lightweight embankment material, and a retaining wall 20 (usually an H-section steel 21 erected on a foundation as a support column) The intermediate concrete floor slab 30a is formed as necessary between the sloped ground 1 and the concrete floor, and the concrete floor is formed thereon. A plate 30 is formed. An outer earth retaining wall 40 is formed integrally with the concrete floor slab 30 at the side edge of the retaining wall side of the concrete floor slab 30, and the finishing material 2 such as crushed stone is embedded so as not to exceed the height, Asphalt and concrete are laid from above to form the road 3. In the case of the urethane method, a lightweight embankment material by urethane foam is formed between the retaining wall 20 and the inclined land 1 instead of stacking the resin foam blocks.
[0003]
By the way, hard foams such as EPS and urethane are viscoelastic materials. Therefore, it is known that when the road 3 is formed on the concrete floor slab 30, it is elastically deformed by its weight and then creep deformed. For this purpose, in a structure based on a normal lightweight embankment method, an appropriate means (not shown) is interposed between the H-shaped steel 21 as a support and the lightweight embankment material 10 so that the light embankment material is not restrained. 10 is allowed to sink downward so that unnecessary stress concentration does not occur in the structure.
[0004]
The same consideration is given to the concrete floor slab 30 and the outer earth retaining wall 40, and the concrete floor slab 30 has a structure independent of the H-section steel 21 on the lightweight embankment material 10, as shown in FIG. An outer earth retaining wall 40 is formed on the concrete floor slab 30 as a structure independent of the H-shaped steel 21. Therefore, even if the concrete slab 30, the outer earth retaining wall 40, and the road 3 created thereon are slightly subsided as a whole due to the sinking of the lightweight embankment material 10 that occurs during and after the construction, There is no particular inconvenience. For example, the construction error of the road structure is allowed to be about ± 3 cm. However, in the case of a normal EPS method, the amount of elastic settlement is about 0.4% of the pile height and the embankment height is 6. If it is about 0 m or less, it is a subsidence of about 2.4 cm at most, and can be within the construction error.
[0005]
[Problems to be solved by the invention]
In recent years, the cost advantage of the construction by the lightweight embankment method described above has been further recognized, and high evaluation has been obtained for the stability as a construction. Expectations are increasing for lightweight embankment construction with higher embankment heights. Actually, construction of road structures having a height of embankment exceeding 10 m is also being carried out.
[0006]
In such a case, according to the same construction method as before, for example, when the height of the embankment is 10 m, the light weight embankment will cause subsidence of 4.0 cm or more, and the elastic settlement due to the light weight embankment material. The creep deformation is a value that cannot be ignored. Therefore, during construction, it is necessary to adjust the error by moving up and down, for example, by adding concrete to the upper surface of the outer earth retaining wall 40, replenishing the earth and sand, and repairing to the planned height. Become.
[0007]
In JP-A-2000-282470, when a concrete floor slab and an outer retaining wall are integrated on a stacked foamed plastic block, the vicinity of the outer retaining wall is provided as a retaining wall. It is described that the stability of the whole structure is improved by supporting the steel structure from the back side with an H-shaped steel, which is a support column, and disposing a low-density foam plastic block in part.
[0008]
In this structure, the portion of the outer retaining wall is supported from the back by the H-shaped steel as a support, and the height does not deviate from the planned height during and after the construction. Therefore, it is not necessary to perform repairs to the planned height by adding concrete to the upper surface of the outer earth retaining wall after construction. However, even if a low-density foam plastic block is placed in part, elastic settlement and creep deformation occur due to the lightweight plastic foam foam block, and it is located above the stacked foam plastic block. It cannot be avoided that the concrete slab part that sinks sinks. Due to the sedimentation, concentrated stress is generated between the concrete slab portion and the portion of the outer earth retaining wall that is immovably supported by the H-shaped steel from the back surface, and there is a possibility that cracks and fractures may occur there.
[0009]
The present invention has been made in view of the circumstances as described above, and in a construction by a lightweight embankment method, an outer retaining wall is easily constructed at a planned height level, and the height is maintained over a long period of time. Another object of the present invention is to provide a structure that can completely eliminate the occurrence of cracks and breakage in a concrete slab due to stress concentration caused by the sinking of a lightweight embankment material.
[0010]
[Means for Solving the Problems]
The present invention relates to a construction by a lightweight embankment method comprising at least a concrete floor slab on an upper surface of a lightweight embankment material, wherein a strut is built on a side surface of the light embankment material, and an outer earth retaining wall is used as the base material and the outer earth retaining wall is the concrete floor. It is constructed as a structure independent of the plate.
[0011]
In the construction by the lightweight embankment method according to the present invention, the outer retaining wall is constructed with the pillars erected on the side surface of the lightweight embankment material as the base material, so it is easy to construct the outer retaining wall at the planned height level. As long as the structure is in a normal shared state, its height can be kept constant over a long period of time. In addition, the outer retaining wall is a structure that is separated from the concrete floor slab, and even if the concrete floor slab sinks due to the sinking of the light weight embankment material, the subsidence is not affected by the outer retaining wall. It does not affect the walls. Therefore, the structure is stable, and even if the lightweight embankment material is elastically deformed or creep-deformed as designed or exceeds the designed value, replenishment of earth and sand is performed regardless of the amount of deformation. By paving, it can be easily restored to the planned height.
[0012]
In the present invention, there is no limit to the lightweight embankment method. For example, an expanded polystyrene block (EPS block) is used as a lightweight embankment material, and the urethane foam is generated between the retaining wall and the slope by stacking the blocks in multiple stages. In addition, a urethane construction method using the urethane foam as a lightweight embedding material, etc., a pillar such as an H-shaped steel was built on one or both sides, and a lightweight embankment material was embedded vertically along the pillar. Any lightweight embankment method can be applied. Moreover, the support | pillar may be built only for the purpose as a base material of an outer earth retaining wall, and what was built in order to build what is called a retaining wall may be utilized. The column is generally H-shaped steel, but is not limited to this provided that it has the required strength.
[0013]
In the lightweight embankment method, after constructing the outer retaining wall and the concrete slab, finishing materials such as crushed stone and earth and sand are loaded on the concrete floor slab to the height of the outer retaining wall, and the asphalt is placed on it. A road is formed by paving. If the pile height of the embankment material is high and the amount of subsidence (elastic deformation, etc.) increases, the concrete floor sunk and the lower end of the outer retaining wall that maintains the specified height There may be a case where a gap is formed between and a finishing material such as crushed stone loaded from the gap flows out.
[0014]
Therefore, in a preferred embodiment of the lightweight embankment construction method according to the present invention, a finishing material such as crushed stone loaded on the concrete floor slab is formed between the outer retaining wall and the concrete floor slab. A blocking member is arranged to prevent passage through a gap that can be made. The blocking member may be a mesh-like flexible member, and has at least a surface in contact with the side surface of the outer retaining wall, and is held in a self-position so that it sinks as the concrete slab settles. It may be a member having a property. In the former case, it is possible to prevent outflow from the gap by using a mesh-like member having a stitch size that does not allow the finishing material to pass. In the latter case, the blocking member and the outer earth retaining wall Since the gap is not generated even if the concrete slab settles, the outflow of the finishing material can be effectively prevented.
[0015]
In the case of using a self-position-holding blocking member having at least a surface in contact with the side surface of the outer earth retaining wall, the blocking member may have any cross-sectional shape as long as it can sink together with the concrete floor slab. There are no restrictions. Alternatively, it may be formed separately from the concrete floor slab and integrated with the concrete floor slab afterwards by an appropriate means. However, it is a preferable aspect that the blocking member is constructed as an integral structure with the concrete floor slab because of the ease of construction on site. In addition, in order not to inadvertently form a gap between the side surface of the outer earth retaining wall and the abutting surface of the blocking member, and to prevent inadvertent stress concentration and damage due to friction between the two, It is a preferable aspect of the structure that an elastic material is sandwiched between the blocking member and the side surface of the outer earth retaining wall as a joint material. As the joint material, any one of bituminous board, bituminous fiber board, rubber foam, resin foam, or a combination thereof is effective.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, referring to the drawings, a construction by a lightweight embankment method according to the present invention will be described based on some embodiments of a road structure as an example. FIG. 1 is a cross-sectional view showing a main part of the first embodiment, and FIG. 2 is a cross-sectional view showing a state in which a concrete floor slab that may occur in the structure shown in FIG. FIG. 3 is a cross-sectional view showing a main part of the second embodiment, and FIG. 4 is a cross-sectional view showing a state in which a concrete floor slab that may occur in the structure shown in FIG. Further, FIG. 5 is a cross-sectional view showing a main part of the third embodiment, and FIG. 6 is a cross-sectional view showing a state in which a concrete floor slab that may occur in the structure shown in FIG. FIG. 7 is a cross-sectional view showing the main part of the fourth embodiment.
[0017]
In the illustrated embodiment, except for the construction structure of the outer earth retaining wall and the structural relationship between the outer earth retaining wall and the concrete floor slab, the other structures are based on the lightweight embankment method illustrated in FIG. It may be the same as the construct. Accordingly, in the following description, only the above-described differences will be mainly described, and in other configurations, members having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.
[0018]
In FIG. 1, an H-shaped steel 21 as a support is built in a foundation ground, and a wall surface material 22 is attached to the side surface of the retaining wall 20. In the example shown in the figure, for example, as described in JP-A-2000-73367, a rectangular wall surface material 22 such as an extruded cement plate is used to form H-shaped steel in multiple stages by using appropriate fastening metal fittings 23. Although the retaining wall 20 is constructed by being fixed to the wall 21, the wall surface material 22 may be anything, and in some cases, if the H-section steel 21 is built as a support, the wall surface material 22. It does not have to be itself.
[0019]
A resin foam block (for example, EPS block) 10 as a lightweight embankment material is stacked in multiple stages on the side opposite to the wall surface material 22 of the H-shaped steel 21, and a concrete floor slab 30 is formed thereon by a conventional method. Is formed. As explained in the road structure shown in FIG. 8, the concrete floor slab 30 is formed on the lightweight embankment material 10 as a structure independent of the H-section steel 21. When subsidence (elastic deformation / creep deformation) occurs, the concrete slab 30 slightly settles regardless of the H-shaped steel 21 according to the amount. In the illustrated example, the mounting bracket 32 is screwed to the tip of an anchor member 31 such as a steel bar embedded in the concrete floor slab 30 so as to be slidably engaged with the flange 24 of the H-section steel 21 in the vertical direction. By engaging, the concrete floor slab 30 can be submerged. In addition, the mounting structure of such a concrete floor slab can divert what is described in Unexamined-Japanese-Patent No. 8-27819, Unexamined-Japanese-Patent No. 11-209999, etc., for example.
[0020]
In the road structure according to the present invention, the outer earth retaining wall 40 is constructed as a structure independent of the concrete slab 30 as shown in the figure, with the H-shaped steel 21 as a base material on the tip side of the H-shaped steel 21. Is done. In construction, a U-shaped frame (not shown) is built over the required section between the adjacent H-section steels 21 and 21, and the necessary reinforcements (not shown) are placed therein. Just cast the cast-in-place concrete to the height, wait for the concrete to harden, and remove the formwork. Thereafter, a finishing material 2 such as crushed stone, gravel, earth and sand, etc. is embedded on the concrete floor slab 30 at a predetermined height, and the road 3 is completed by paving with asphalt or concrete.
[0021]
In the above structure, the outer earth retaining wall 40 and the concrete floor slab 30 are independent edge-cut structures. Therefore, as shown in FIG. 2, the concrete floor slab together with the resin foam block 10 which is a lightweight embankment material. Even if 30 sinks, the sinking does not affect the outer earth retaining wall 40. This makes the construct stable. Even when the resin foam block 10 is elastically deformed or creep deformed as designed, depending on the amount of deformation, replenishment 2a such as earth and sand and pavement can be used to easily create roads of the planned height. Obtainable.
[0022]
In the above structure, when the stacked height of the resin foam block 10 is high and the sinking amount (elastic deformation amount, etc.) becomes large, the predetermined height is maintained with the subsidized concrete floor slab 30. The gap H (FIG. 2) generated between the outer earth retaining wall 40 and the lower end of the outer earth retaining wall 40 may increase, and the finishing material 2 such as crushed stone loaded from the gap H may flow out. The second form shown in FIG. 3 addresses such a situation. In this aspect, the entire length of the route is between the inner side wall surface 41 of the outer earth retaining wall 40 and the upper surface of the concrete floor slab 30. A net-like member 50 made of a material such as a nonwoven fabric or net made of resin fibers such as polypropylene fiber, polyethylene fiber, and polyester fiber is attached as an outflow prevention member. Other configurations are the same as those shown in FIG.
[0023]
In this aspect, as shown in FIG. 4 in which the concrete floor slab 30 has settled, the wide gap formed by sedimentation is covered by the net-like member 50, so that the finishing material 2 does not pass through. By using the net-like member 50 having a knitted stitch of a size, it is possible to effectively prevent crushed stone and earth and sand from flowing out from the gap.
[0024]
FIG. 5 shows a third aspect. In this aspect, a ridge 51 having a rectangular cross section that functions as an outflow prevention member on the upper surface side of the concrete slab 30 so as to be in contact with the inner wall surface 41 of the outer earth retaining wall 40 formed on the H-section steel 21. However, it is formed integrally with the concrete floor slab 30 over the entire length of the route. And the material which has elasticity which is a bituminous board, a bituminous fiber board, a rubber foam, a resin foam, etc. in the surface where the outer side surface 52 of this protruding item | line 51 collides with the inner wall surface 41 of the outer earth retaining wall 40 Is inserted and clamped as a joint material 60.
[0025]
In this aspect, even if the concrete floor slab 30 sinks, the outer surface 52 of the ridge 51 and the inner wall surface 41 of the outer earth retaining wall 40 can always be kept in contact with each other, as shown in FIG. Moreover, even if the concrete floor slab 30 sinks, no gap is generated, so that the outflow of the finishing material 2 can be effectively prevented. In addition, since the joint material 60 is interposed between the two, in addition to preventing the generation of the gap more effectively, the friction between the concrete wall surfaces when they move with each other in direct contact with each other is reduced. It is also possible to avoid inadvertent stress concentration and breakage due to.
[0026]
In addition, although not shown in figure, it replaces with the net-like member 50 and the protruding item | line 51 as a flow-out prevention member, and is provided with a certain amount of self-orientation retention property (for example, rubber material, resin material, wood material, metal material etc.). A member having an L-shaped cross section may be arranged such that two L-shaped side surfaces are in contact with the inner wall surface 41 of the outer earth retaining wall 40 and the upper surface 33 of the concrete floor slab 30. . At that time, the side surface contacting the concrete floor slab 30 may be integrally fixed to the concrete floor slab 30. The joint material 60 described above may be inserted and sandwiched between the inner wall surface 41 of the outer earth retaining wall 40 and the side surface in contact therewith. Furthermore, in the example of FIG. 5, the protrusion 51 having a rectangular cross section is only one example, and the cross sectional shape has a surface that can contact the inner wall surface 41 of the outer earth retaining wall 40 on one side surface. If it is, other shapes are arbitrary and there is no restriction | limiting.
[0027]
FIG. 7 shows a fourth aspect. In the first to third aspects, the H-shaped steel 21 is built only on one side of the road, and the resin foam block 10 is loaded on the other side using the slope of the mountain, as shown in FIG. In the aspect, the H-shaped steels 21 and 21 are built on both sides of the road, and the resin foam block 10 is stacked between them to construct the road. Even in this case, it is clear that the same effect can be obtained. In addition, in the example of illustration, although the structure using the protruding item | line 51 and the joint plate 60 which were demonstrated based on FIG. 5, FIG. 6 is shown, this is an illustration and the arbitrary shown to the 1st-3rd aspect. The following structure can be used. Different structures can be employed on the right and left sides.
[0028]
【The invention's effect】
As described above, in the structure by the lightweight embankment method according to the present invention, the outer earth retaining wall can be easily constructed at the planned height level, and the height can be maintained over a long period of time. As in the case of, the work of repairing to the planned height by adding concrete to the upper surface of the outer earth retaining wall after construction is unnecessary, but on the other hand, due to the stress concentration caused by the sinking of the lightweight embankment material Thus, it is possible to completely eliminate the occurrence of cracks and breakage in the concrete slab, and it is possible to obtain a highly stable structure that is highly practical.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of a first embodiment of a road structure which is an example of a structure by a lightweight embankment method according to the present invention.
FIG. 2 is a cross-sectional view showing a state in which a concrete slab that may occur in the structure of FIG.
FIG. 3 is a cross-sectional view showing a main part of a second embodiment.
4 is a cross-sectional view showing a state in which a concrete floor slab that may occur in the structure of FIG. 3 has settled.
FIG. 5 is a cross-sectional view showing a main part of a third embodiment.
6 is a cross-sectional view showing a state in which a concrete floor slab that may occur in the structure of FIG. 5 has settled.
FIG. 7 is a cross-sectional view showing a main part of a third embodiment.
FIG. 8 is a cross-sectional view showing an example of a structure by a conventional lightweight embankment method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 ... Road, 10 ... Resin foam block as lightweight embankment material, 20 ... Retaining wall, 21 ... H-section steel as a support, 24 ... H-section steel flange, 22 ... Wall material, 30 ... Concrete floor slab, 31 ... An anchor member such as a steel bar, 40 ... Outer earth retaining wall, 50 ... A net-like member as a blocking member, 51 ... A ridge as a blocking member, 60 ... A joint material

Claims (7)

In a structure by a lightweight embankment method that has at least a concrete floor slab on the upper surface of the lightweight embankment material, a pillar is built on the side surface of the lightweight embankment material, and the outer earth retaining wall is independent of the concrete slab with the pillar as a base material. A structure by a lightweight embankment method characterized by being constructed as a finished structure. In order to prevent the finishing material 2 such as crushed stone loaded on the concrete floor slab from passing through the gap that can be formed between the outer retaining wall and the concrete floor slab. The structure by the lightweight embankment method of Claim 1 by which the member is arrange | positioned. The construction according to claim 2, wherein the blocking member is a net-like member. 3. The light weight according to claim 2, wherein the blocking member has at least a surface in contact with the side surface of the outer earth retaining wall, and the blocking member sinks as the concrete slab settles. A structure by the embankment method. The construction according to claim 4, wherein the blocking member is constructed as an integral structure with the concrete floor slab. 6. The lightweight embankment construction according to claim 4 or 5, wherein an elastic material is sandwiched as a joint material on a surface where the blocking member and the side surface of the outer earth retaining wall are in contact with each other. 7. The lightweight embankment construction according to claim 6, wherein the joint material is any one of a bituminous board, a bituminous fiber board, a rubber foam, a resin foam, or a combination thereof.

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