JPS63176512A - Block-stacked retaining wall for revetment of river and its construction - Google Patents

Abstract

PURPOSE:To permit the use of river-bed water under the ground by using water- permeable concrete blocks for the portion lower than the riverbed of a concrete block-stacked retaining wall. CONSTITUTION:Usual water-impermeable concrete blocks 3 are used for the lowest stage blocks in contact with the upside of a foundation concrete 7. Water-permeable porous concrete blocks 2 are also used for a part or all of blocks lower than the riverbed and its neighbor, and usual concrete blocks 3 are used for the portion high than the riverbed to construct a retaining wall 1. Since river-bed water under the ground from river passes through the blocks 2, the river-bed water can be used as a resource for agricultural and city waters.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a block retaining wall for revetment of rivers, etc., and a method of constructing the same.

[Conventional technology]

It is well known that river banks are constructed with block retaining walls.

In other words, conventionally known standard structures of block retaining walls for bank protection include those that do not use backing concrete and those that use backing concrete, but concrete block retaining walls for bank protection for river construction are As a general rule, concrete backfilling is not allowed except in special cases, and a typical concrete block retaining wall for a river bank is constructed as shown in FIG. 5, for example.

In other words, in FIG.
26 is the top concrete, 27 is the foundation concrete, and the block retaining wall 21 has its lower part 21a deeply rooted below the river bed surface 10. , behind which a backfilling material 28 such as crushed stone or chestnut stone is backfilled.

In this way, although impermeable backfill concrete is not used for the backfilling material 28 of the block retaining wall 1 for ordinary river revetment, the block retaining wall 21 itself is made of impermeable material. Since it is composed of a concrete block 23 and an impermeable concrete body 25,
As a whole, the entire surface had no water permeability at all, except for the drain hole (not shown) drilled in the wall surface exposed above the water surface.

[Problem that the invention seeks to solve]

By the way, such a concrete block retaining wall 21
In order to ensure bank protection against lowering of the river bed and scouring due to gravel extraction, the depth of the roots has been gradually increasing in recent years, and in recent years, the depth has been increased by more than 1 meter from the deepest riverbed level. ing.

In this way, the need to increase the penetration depth means that the roughness coefficient of the river decreases due to river improvement, and as the flow velocity increases, the scouring force during floods will inevitably increase. Although it is unavoidable, until now no consideration has been given to deepening the penetration depth of this impermeable concrete block retaining wall 21 by more than 1 meter from the deepest part of the riverbed. Although this was not the case, the following problems arise.

In other words, the lateral movement of underground water from the river is restricted or blocked by the part where the retaining wall 21 is embedded, which inevitably causes a drop in the underground water level in the area surrounding the river. As a result, similar problems have arisen in that it is no longer possible to obtain groundwater, which was abundant in the case of the old dry stone embankment.

[Means for solving problems]

This invention aims to provide the following concrete block retaining wall and its construction method in order to solve the above-mentioned problems brought about by recent concrete block retaining walls. It is something.

That is, the gist of the first invention is a concrete block retaining wall formed by fixing the retaining portions of accumulated concrete blocks with body-filling concrete, the retaining wall comprising: A part or all of the concrete blocks constituting the section are composed of water-permeable concrete blocks, and from the vicinity of the river bed of the concrete block retaining wall, the following parts are connected from the river bed to the back of the retaining wall. A block retaining wall for revetment of a river etc. is characterized by being imparted with water permeability, and the gist of the second invention is that when constructing a block retaining wall for revetment of a river etc., In the area below near the river bed where permeable concrete blocks are used as concrete blocks, when FJ3 water permeable concrete blocks are sequentially accumulated, the end of the retaining part of the permeable concrete blocks is placed behind the stacked permeable concrete blocks. Place a paper form in which a notch into which the end of the retaining part can be fitted is formed in advance at the position where the two abut each other, and insert the notch of the paper form into the end of the retaining part of each water-permeable concrete block. The method is characterized in that, in a state where the paper formwork is fitted and each retaining part end is exposed behind the paper formwork, an inhospitable water-permeable concrete is placed between the paper formwork and each water permeable concrete block. A method of constructing a block retaining wall for revetment of rivers, etc.

[Effect]

In the concrete block retaining wall for bank protection according to the first invention, some or all of the concrete blocks constituting the following parts near the river bed of the concrete block retaining wall are made of water-permeable concrete blocks. Therefore, the concrete block constituting the area below the riverbed area of this concrete block retaining wall should be constructed with water-permeable concrete block, or the concrete block If the concrete that constitutes the following parts of the retaining wall near the river bed is impermeable concrete, the concrete that forms the area below the riverbed area of the retaining wall is at least the end face of the retaining part of the permeable concrete block. If concrete is placed between each permeable concrete block to prevent blockage, the entire back surface of the part where this concrete block retaining wall is embedded below near the river bed. Or, at least in the portion where the butting end of the water-permeable concrete block is exposed from the body-filling concrete, water permeability is imparted to the river bed to the water-permeable backfill material behind the retaining wall.

In addition, the permeability coefficient of the backfill soil in front and back of the part where this concrete block retaining wall is embedded is generally quite small on the order of 10-', whereas the permeability coefficient of the permeable concrete block is quite small. Since the coefficient is usually on the order of 10-1, which is very large compared to the hydraulic conductivity of the backfill soil, the concrete block retaining wall according to the present invention is embedded below near the river bed. If the water-permeable concrete block has the water permeability described above, the underground water of the river protected by the concrete block retaining wall can be absorbed by the water-permeable concrete block. Through the section, it can be moved laterally, as in the case of old dry stone revetments.

As mentioned above, in the block retaining wall for revetment according to the first invention, all or part of the concrete blocks constituting the vicinity of the riverbed and below are made of water permeable concrete blocks, and at least the water permeable concrete blocks are made of water permeable concrete blocks. Even if a permeable concrete block is fixed with impermeable concrete, it must be constructed so that the impermeable concrete does not adhere even to the end face of the permeable concrete block. However, according to the second invention, such construction can be performed extremely easily and reliably.

That is, in this second invention, when the water-permeable concrete blocks are sequentially accumulated, a paper form is placed behind the water-permeable blocks stacked sequentially from the bottom, and the paper form is formed in advance. A certain notch is fitted into the end of each permeable block, the end of each part is slightly protruded behind the paper form, and concrete is placed between the paper form and each permeable block. Since this is a method of encasing the paper form, it is necessary to prevent impermeable concrete from adhering to at least the edge of the permeable concrete block exposed or protruding behind the paper formwork, that is, at least to the end face thereof. Filling concrete can be poured in front of the paper formwork between each permeable concrete block.

[Example-1] 1. To explain the example with reference to Fig. 1, (1) is concrete blocks 2.2...
A concrete block retaining wall constructed by fixing the retaining parts of 3 and 3 with concrete blocks 4 and 5, 6 is concrete at the top, 7 is concrete at the base, and 8 is crushed stone. or a backfilling material such as millet, and 9 is an earthen embankment, but the concrete block retaining wall 1 according to the present invention has a part where it is embedded below the riverbed level 10, especially the following: It is structured as follows.

That is, in this embodiment, the lowest level concrete block in contact with the top of the foundation concrete 7 is an ordinary impermeable concrete block 3, and the other concrete blocks below the vicinity of the riverbed are: A retaining wall 1 is constructed by using porous water-permeable concrete blocks 2 for all or part of the wall, and using water-impermeable ordinary concrete blocks 3 for the concrete blocks above it. In the area where the water-permeable concrete block 2 is used, the water-permeable concrete block 2 is fixed using porous water-permeable concrete 4 to the body-filling concrete, and the impermeable concrete block 2 is fixed to the body-filling concrete. In areas where ordinary concrete blocks 3 are used, as in the case of conventional concrete block retaining walls, impermeable ordinary concrete 5 is used as the body concrete, and the impermeable concrete blocks are 3 is fixed.

In addition, the porous water-permeable concrete block 2 and the water-permeable body-filling concrete 4 are made of mixed materials with the same specific gravity as the water-permeable ordinary concrete block 3 and the water-impermeable ordinary body-filling concrete 5. By slightly lowering the weight per volume compared to ordinary concrete (for example, 9-hole concrete is 2.3t/n (while porous concrete is 2.0t/+T?), it has a large number of fine particles. Since pores are formed in the retaining wall, the portion 1a of the retaining wall made of the porous water-permeable concrete blocks 2 and the water-permeable concrete 4 is used to compensate for the resistance moment reduced due to the weight reduction of the retaining wall. Then, the length L is determined by the impermeable ordinary concrete block 3 and the ordinary concrete block 5.
It is slightly longer than when constructed using .

(Example 2) Another example will be explained with reference to Figures 2 to 4. This example deals with the case where most of the concrete blocks below the river bed area are permeable concrete blocks. This case relates to a case where a porous water-permeable concrete plate 2 forming a part 1a below the vicinity of the riverbed of the retaining wall 1 is fixed with an ordinary water-impermeable concrete body 5.

In this embodiment, the length 1 of the retaining part 2a of the water permeable concrete block 2 is set to the length 1 of the retaining part 2a of the water permeable concrete block 2.
This part 1a is constructed according to the second invention in order to make the length of the retaining part 3a slightly longer than that of the retaining part 3a, and to prevent the impervious concrete 5 from adhering to the end face 2b of the retaining part 2a. , each water permeable concrete block 2
Water-impermeable concrete 5 is placed in between.

In other words, in the area 1a below the river bed area where permeable concrete blocks 2 are used as concrete blocks, when the permeable concrete blocks 2 are sequentially accumulated, for example, as shown in the third area, they are accumulated. Using a paper form 12, which has a notch 11 large enough to fit the end of the retaining portion 2a of the water-permeable block 2 in advance at the position where the end surface 2b of the retaining portion 2a contacts, is applied to the back of the stacked water permeable blocks 2, and the above-mentioned notch 11 of the paper form 12 is attached to each retaining part 2a of the stacked water permeable blocks 2.
When fitting the end faces 2b of each retaining portion 2a to the back of the paper form 12, place an impermeable body concrete 5 inside the paper form 12. Even when poured, the concrete 5 does not adhere to the end surface 2b of the retaining portion 2a of the permeable concrete block 2.
It is packed between each water permeable block 2.

Therefore, according to the second invention, the concrete block retaining wall 1 of this invention (first invention) constructed in this way is composed of the permeable concrete blocks 2 and the impermeable concrete 5. part 1
Required water permeability is imparted to this retaining wall 1 at least at a portion where the end face 2b of the retaining portion 2a of the water permeable concrete block 2 is in contact with the water permeable backfill material 8.

Note that the paper formwork 12 used to carry out the second invention
Other embodiments are shown in FIGS. 4-1 and 4-2. Moreover, in the embodiment shown in FIG. 4-2, the notch 11 formed in the paper form 12 is formed in the shape of a thank-you note.

[Effects of the Invention] The block retaining wall for revetment according to the first invention particularly protects all or part of the area below the river bed where the concrete block retaining wall constituting it is embedded. Since it is constructed of water-permeable concrete blocks, at least the backfill soil in the part where this concrete block retaining wall is embedded, and at least the water permeability of this concrete block retaining wall with water-permeable concrete blocks. If the backfilling material that is in contact with the back side of the part that has been given water permeability is provided, that is, without using water-impermeable concrete for the backfilling material, (
If concrete is used as the backfill material, if water permeability is imparted (by using porous concrete for the backfill concrete), this block area retaining wall will be made of particularly water permeable concrete blocks. This gives the area where this block retaining wall is rooted a moderate amount of water permeability, and as in the case of the old blank masonry retaining wall, it prevents underground water from flowing from rivers. It may be moved laterally across the retaining wall.

In addition, most of the part of this block retaining wall made of porous concrete blocks is embedded under the river bed, so the part of the block retaining wall is made of porous concrete blocks. Underground water from the permeating river side is filtered by the river bed backfill soil that forms the river bed surface, and then passes through this permeable concrete block section, so the underground water in this direction is , this water-permeable porous concrete block does not become clogged to the extent that it loses the above-mentioned functions.

If the water-permeable concrete block is slightly clogged due to underground water flowing in this direction, such clogging can be repeatedly eliminated by the following backwashing action.

This is because when the water level of the river is higher than the groundwater level behind the retaining wall, underground water flows from the river side toward the back of the retaining wall, but as in the case after rain, underground water flows behind the retaining wall. If the groundwater level is higher than the water level on the river side, underground water will flow in the opposite direction to the above, so at this time,
This is because the clogging caused as described above will be backwashed by this backflow water.

Therefore, according to the block retaining wall for revetment of the first invention, the drawbacks of the conventional concrete block retaining wall for revetment, as mentioned at the beginning, can be solved, and the area behind the retaining wall can be It is possible to enjoy the benefits of underground underground water from rivers such as rivers, and the underground underground water can be used as agricultural water or a water supply source.

Further, according to the second invention, a water-permeable block for imparting water permeability as described above to a block retaining wall is maintained so as not to destroy its water permeability, and a water-impermeable block with excellent strength is provided. It can be easily constructed using concrete.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view of a concrete block retaining wall showing a first embodiment of the present invention, and FIG. 2 is a longitudinal side view of a concrete block retaining wall showing the construction state of the second embodiment. FIG. 3 is a rear view of the same, FIGS. 4-1 and 4-2 are front views showing examples of paper forms, respectively, and FIG. 5 is a vertical side view of a conventional concrete block retaining wall. DESCRIPTION OF SYMBOLS 1... Concrete block retaining wall, 2... Water permeable concrete block, 2a... Retaining part, 2b... End face, 3... Impermeable concrete block, 4... Water permeable body Filled concrete, 5... Impermeable body filled concrete, 11... Notch, 12... Paper formwork. Patent applicant Agent: Kaihatsu Concrete Co., Ltd. (6
370) Patent Attorney Takemi Nishimura Figure 1 Figure 2 To Figure 1'' 1-2 Figure 3 I Figure 4-1 Figure 4-2 Figure 5

Claims (1)

[Scope of Claims] 1. A concrete block retaining wall formed by fixing the retaining parts of accumulated concrete blocks with body-filling concrete, which comprises the following parts from the vicinity of the riverbed of the concrete block retaining wall: Some or all of the concrete blocks are made of water-permeable concrete blocks, and the following parts of the concrete block retaining wall near the river bed are provided with water permeability that leads from the river bed to the back of the retaining wall. A block retaining wall for river bank protection, which is characterized by: 2. The river etc. according to claim 1, wherein among the concrete bodies, the concrete constituting the portion of the block retaining wall from the vicinity of the riverbed is water-permeable concrete. block retaining wall for seawall. 3. The concrete block constituting the following parts near the river bed of the concrete block retaining wall is made of impermeable concrete, and the retaining part is fixed by the concrete block. 2. A block retaining wall for a bank of a river or the like according to claim 1, wherein the end of the retaining part of the water-permeable concrete block is exposed from the water-impermeable concrete. 4. When constructing a block retaining wall for bank protection of a river, etc., in the areas below near the riverbed where permeable concrete blocks are used as concrete blocks, when the permeable concrete blocks are sequentially accumulated, Behind the water-permeable concrete block, place a paper form with pre-formed notches into which the ends of the retaining parts of the water-permeable concrete blocks will come into contact, and The above cutout parts of the frame are fitted to the ends of the retaining parts of each water-permeable concrete block, and with the ends of each retaining part exposed behind the paper formwork, the paper formwork and each water-permeable concrete block are connected. A method for constructing a block retaining wall for revetment of rivers, etc., characterized by placing impermeable concrete in between.