JP3728725B2 - River bed structure and river bed protection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a riverbed and riverbed protection technique, and more particularly to a multi-natural riverbed structure and a riverbed protection method.
[0002]
[Prior art]
There are known floor protection works, floor stop works, and drop works for laying and protecting hard structures such as concrete floor blocks and water hitting on riverbeds and heads.
[0003]
[Problems to be solved by the invention]
The river bed structure described above has several problems as follows.
<I> The laying location of hard structures that have been subjected to floor protection work, drop work, etc. has a faster flow rate, and not only the upstream and downstream parts of the hard structure are easily scoured locally, but also the scouring of the river bed It spreads over a wide area.
Therefore, scouring destruction of the surrounding revetment structures and foundations, sliding of the revetment structures, and overturning destruction are induced, and in the worst case, the levee body collapses and may cause heavy flood damage.
<B> With local scouring of the upstream and downstream portions of the hard structure, the hard structure itself may be destroyed.
<C> The laying location of the hard structure has a high flow rate, and in the case of a head work, it inhibits the movement of underwater habitats.
Therefore, it is necessary to install various fishway structures separately, but these fishway structures do not fully consider the fish ecosystem and the swimming ability of juvenile fish, and also harmonize with the surrounding landscape. There is no particular consideration.
<D> Recently, the idea of riverbed protection has been shifting from emphasis on strength and function to emphasis on the environment. Covering the entire riverbed with concrete, the riverbed protection method is not only poor in landscape but also incompatible as a habitat for aquatic organisms such as fish and waterside plants. The proposal of a technology that can restore and conserve natural ecosystems is desired.
[0004]
The present invention has been made in view of the above points, and its object is to provide a riverbed structure and a riverbed protection method that can effectively prevent local scouring of the riverbed with simple construction. There is to do.
Still another object of the present invention is to provide a riverbed structure and a riverbed protection method capable of restoring and conserving natural ecosystems by reducing flow velocity and improving landscape.
[0005]
The invention according to claim 1 is a structure for protecting a river bed having a hard girdle structure, wherein a plurality of weight bodies project from the upstream and downstream portions of the hard glove structure, respectively. in combination with flexible slow flow mat having both preventing action and the flow rate reducing action and fishway effect drilling, one kind or two kinds of the cage of stone containing packed with stone in the accommodating basket having a flexible Provides a riverbed structure characterized by installation.
The invention according to claim 2, respectively the upstream portion and the downstream portion of the rigid Mamoruyuka structure, characterized by being installed in a single combination of any one one of Yururyu mat or stone-filled baskets body A riverbed structure according to claim 1 is provided.
Invention is characterized in that each installed with the upstream portion and the downstream portion of the rigid Mamoruyuka structure as pair basket of Yururyu mat and stone containing the structure of riverbed of claim 1 according to claim 3 I will provide a.
The invention according to claim 4 is characterized in that any one of a slow flow mat and a stone-containing frame and a combination of two are installed as a pair in the upstream portion and the downstream portion of the hard protection floor structure, respectively. The riverbed structure according to claim 1 is provided.
The invention according to claim 5 is a method for protecting a river bed having a hard girder structure, wherein a plurality of weights are projected on the surface of the scouring area of the upstream and downstream parts of the hard girder structure. A method for protecting a river bed, characterized in that one or two of a slow-flow mat provided and a stone-encased body in which stones are packed in a flexible storage rod are installed to cover the river bed I will provide a.
[0006]
Furthermore, the present invention may be the riverbed structure according to claim 1, wherein a slow flow mat is installed in an upstream portion and a downstream portion of the hard protection floor structure.
Furthermore, the present invention may be the riverbed structure according to claim 1, wherein a stone-containing frame is installed in an upstream portion and a downstream portion of the hard protection floor structure.
[0007]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0008]
<A> Slow flow mat FIG. 1 shows a mode in which slow flow mats 30 and 30 are laid on the upstream and downstream riverbeds 20 of the existing hard floor structure 10.
[0009]
The hard floor structure 10 is constructed of a concrete floor board, block, water hammer, etc., and is constructed on the river bed 20 over a predetermined range along the direction of water flow.
In the present invention, the term “hard floor protection structure 10” is defined and used to include not only a general floor protection work but also a fall work.
[0010]
The slow flow mat 30 includes a flexible sheet-like base material 31 and a plurality of slow flow weight bodies 32 attached to the entire area of one side of the base material 31.
The base material 31 is, for example, a mesh-like woven fabric (plain weave, multiple woven fabric, etc.), a knitted fabric (non-knotted knitted fabric, raschel knitted fabric, etc.), non-woven fabric, geotextile such as geogrid, or a wire mesh that has been plated with zinc or resin-coated. A flexible sheet having excellent corrosion resistance and tensile strength can be used.
In short, it is only necessary to have a tensile strength that does not cause breakage due to the water flow or the weight of the group of slow flow weight bodies 32 at the time of water increase or laying work.
[0011]
The slow flow weight body 32 is a heavy object such as natural stone such as cobblestone or crushed stone, fake stone, concrete block, wood (waste material, thinned material), and is fixed to the base material 31 at a predetermined interval so as not to be separated. .
The “heavy object” in the present example means a substance having a weight that is not easily washed away by a water stream.
As a means for fixing the slow flow weight body 32, for example, a driving method in which pins are driven from the back surface side of the base material 31 toward the slow flow weight body 32, or a fixing method in which bonding is performed using resin, mortar, or the like, a pin and an adhesive It is possible to adopt a method combining the above.
In consideration of the habitat of various underwater habitats, it is desirable that the slow flow weight body 32 be formed non-uniformly using natural stones having different dimensions.
[0012]
<B> Slow flow mat laying range The upstream portion and the downstream portion of the hard floor structure 10 are likely to scour locally.
Therefore, the slow flow mats 30, 30 described above are laid on the upstream and downstream riverbeds 20 of the hard floor structure 10, respectively.
When laying the slow flow mat 30, the end of the slow flow mat 30 is brought into contact with the hard floor structure 10, or close to the last so as not to generate a large gap with the hard floor structure 10.
Due to the flexibility of the base material 31, the slow flow mat 30 follows the undulations of the river bed and covers the river bed.
[0013]
[Action]
Next, the characteristics of the river bed structure described above will be described.
[0014]
<I> Scouring prevention action The slow flow mats 30 and 30 laid on the upstream side and the downstream side of the hard floor structure 10 where local scouring is likely to occur cover the river bed 10 and function as protective members.
Therefore, local scouring on the upstream side and the downstream side of the hard floor structure 10 can be reliably and effectively prevented.
In particular, each slow flow mat 30 is given sufficient weight and the slow flow weight body 32 is firmly fixed, so that the slow flow mat 30 is not swollen by the flood, and the slow flow weight body 32 is not separated and flows. .
[0015]
<B> Flow Rate Reduction Action Since the slow flow weight bodies 32 on the surface of the slow flow mat 30 resist the flow of water, the flow velocity is reduced when passing over the slow flow mat 30.
The decrease in the water flow rate is also useful for the scouring prevention action described above.
[0016]
<C> Scenic Action Slow Flow Mat 30 covers the river bed 20. Therefore, the riverbed 20 is not directly seen only by visually observing the slow-flow weight bodies 32 due to shallow water or a drop in water level.
Further, as will be described later, sand or the like accumulates on the slow flow mat 30 and the vegetation environment is prepared.
From the above factors, the slow flow mat 30 contributes to the landscape.
[0017]
<D> Habitats In general, crushed sand, pebbles, etc. flow down by running water.
These falling objects accumulate between the slow flow weight bodies 32 of the slow flow mat 30 and gradually approach the natural riverbed form.
As the riverbed recovers to its natural state, the habitat of various aquatic organisms such as microorganisms, fish and shellfish, and the habitat of waterfront plants will gradually be in place.
In particular, the slow flow weight bodies 32 of natural stone constituting the slow flow mat 30 and the small-diameter stones and sand that are deposited become resting environments, egg-laying places, and wintering places according to various aquatic organisms.
Of course, the natural purification function of the river is restored as it approaches the tentative form of nature.
Conventionally, when a step is generated by floor stop work, drop work, and floor protection work on the riverbed, a concrete slope was provided on the side of the step part, and a fishway work was performed as in this example, for example The slow flow mat 30 can be used as a fishway material.
[0018]
Second Embodiment of the Invention
Other embodiments will be described below. In the description, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0019]
FIG. 2 shows another embodiment in which the skeletons 40 and 40 are installed on the upstream and downstream riverbeds 20 of the hard girdle structure 10.
[0020]
The housing 40 includes a flexible housing rod 41 and stones (cobbles, crushed stone, concrete blocks, etc.) 42 filled in the housing rod 41.
The container 41 is formed in a box shape or a bag shape using a net structure such as a fish net with a plurality of rope members attached thereto.
When the container 41 is box-shaped, the cover may be formed integrally with the side of the box body or may be a form in which a cover separate from the box body is retrofitted.
When the container 41 is a bag, the overall shape is, for example, a cylindrical shape, a conical shape, a purse-shaped shape, etc., and it may be configured to be able to be lifted by a separate rope after the mouth is squeezed with a rope.
[0021]
Examples of the material of the net structure and rope material described above include polyethylene, polypropylene, polymethyl methacrylate, polyvinyl chloride, polystyrene, polyacrylonitrile, polytetrafluoroethylene, polyester, nylon, aramid fiber, carbon fiber, glass fiber, and the like. As the network structure, for example, a knotless network, a Russell network or the like can be adopted.
[0022]
In addition, as the frame 40, a strip-shaped grid reinforced with aramid fibers is vertically arranged on the river bed 20 and arranged in a corrugated shape, and each corrugated portion of each grid is brought into contact with the anchor pin and attached to an anchor pin. A space of a shape in which a space having a shape is defined and stones are packed in each of these spaces and the housing 40 is assembled on-site may be used, or a known wire-mesh futon bag may be used.
The material, shape, and structure of the housing 40 are not limited to those exemplified above, and it is needless to say that various well-known materials and shapes can be applied.
[0023]
The frame 40 may be laid directly on the river bed 20, but the river bed 20 upstream and downstream of the hard floor structure 10 so that the upper surface of the frame 40 has substantially the same height as the hard floor structure 10. In some cases, a housing hole 21 having a size and depth that can accommodate the housing 40 is formed, and the housing 40 containing the stone 42 is installed in the housing hole 21.
[0024]
Even in this example, as in the first embodiment described above, the scouring 40 containing the stone material 42 located on the upstream and downstream sides of the hard floor structure 10 prevents the local scouring of the riverbed 20; It exhibits a flow velocity lowering effect due to water passing through the housing 40 and a fishway effect due to the stone 42.
[0025]
Embodiment 3 of the Invention
FIG. 3 shows another embodiment in which the aforementioned combination of the frame 40 and the slow flow mat 30 is installed on the upstream and downstream riverbeds 20 of the hard protection floor structure 10. In this example, the case 40 in which the stone body 42 containing the stone material 42 is disposed on the upstream side in the water flow direction and the slow flow mat 30 is disposed adjacent to the downstream side thereof is shown.
[0026]
Although not shown, the above combination may be reversed, and the slow flow mat 30 may be laid on the upstream side, and the housing 40 including the stone material 42 may be disposed on the downstream side.
In short, it is only necessary that different types of the slow flow mat 30 and the frame 40 containing the stone material 42 are provided in parallel in the upstream portion and the downstream portion of the hard protection floor structure 10.
[0027]
Further, as shown in FIG. 4, a long slow flow mat 30 may be laid from the upper surface of the housing 40 installed on the upstream side in the water flow direction toward the downstream side.
In the case of the figure, a part of the slow flow mat 30 covers the upper portion of the casing 40, and the flow rate lowering action of the flowing water and the fishway effect of the casing 40 are further improved.
[0028]
Embodiment 4 of the Invention
You may arrange | position any 1 type or 2 types combining the above-mentioned frame 40 and the slow flow mat 30 in the river bed 20 of the upstream part and downstream part of the hard girth structure 10.
FIG. 5 shows a case where a slow flow mat 30 is laid in the upstream portion of the hard girdle structure 10 and two types of the frame 40 and the slow flow mat 30 are combined in the downstream portion, but other combinations are shown. And the following.
(1) The upstream part is a kind of the casing 40, and the downstream part is a combination of the slow flow mat 30 and the casing 40.
(2) The upstream portion is a combination of two types of the slow flow mat 30 and the casing 40, and the downstream portion is one type of the slow flow mat 30.
(3) The upstream part is a combination of two types of the slow flow mat 30 and the casing, and the downstream part is one type of the casing 40.
[0029]
Embodiment 5 of the Invention
The above describes the case where the slow flow mat 30 and the casing 40 are arranged side by side in the water flow direction. However, the slow flow mat 30 and the casing 40 are directed in the direction intersecting the water flow direction, that is, in the transverse direction of the river bed 20. May be arranged side by side.
[0030]
Embodiment 6 of the Invention
In the first embodiment, the case where the slow flow mat 30 is opposed to running water by its own weight has been described. However, the anchor 50 may be driven and fixed as shown in FIG.
The anchor 50 penetrates the base 31 of the slow flow mat 30 and is directly placed on the river bed 20 or is placed on the hard floor structure 10 if it is a downstream portion of the hard floor structure 10.
When the anchor 50 is driven, the anchor 50 may be distributed not only on the upstream side of the slow flow mat 30 but also distributed throughout.
According to this example, not only the peeling prevention effect of the slow flow mat 30 is increased, but also the design weight of the slow flow weight body 32 can be reduced, and there is an advantage that transportation and handling properties are improved.
[0031]
Further, as another fixing means of the slow flow mat 30, the slow flow mat 30 may be bound to the housing 40. However, as shown in FIG. The portion 33 is formed, and the extra length 33 is embedded and fixed between the bottom of the frame 40 and the river bed 20 or is wound so as to wrap the extra length 33 in the frame 40 as shown in FIG. And fix it.
The extra length portion 33 may be formed not only on the upstream side of the slow flow mat 30 but also on the downstream side.
[0032]
Further, as shown in FIG. 5, the extra length portion 33 may be embedded in the river bed 20.
[0033]
If fixing means by winding the extra length portion 33 around the frame 40 and burying it in the river bed 20 is employed, there is an advantage that the slow flow mat 30 can be firmly fixed without using the anchors 50.
[0034]
Embodiment 7 of the Invention
Although the above demonstrated the case where one type or two types of the slow flow mat 30 and the housing 40 were installed in the upstream part and downstream part of the hard glove structure 10, respectively, the whole surface of the hard glove structure 10 or If the slow flow mat 30 is laid on a part of the surface along the longitudinal direction, the fishway will not be divided by the hard girder structure 10, and the river bed will have a more natural riverbed shape due to the slow flow mat 30, which is more effective. A typical fishway effect can be expected.
[0035]
Furthermore, if one or two types of slow flow mat 30 and skeleton 40 are installed over a certain section of several tens of meters, hundreds of meters, or several kilometers of river channel, the aquatic environment and vegetation environment of Further improve.
[0036]
【The invention's effect】
The present invention can obtain the following effects.
<B> The flexibility of these slow flow mats and housings by simple work of installing one or two types of slow flow mats and housings at the upstream and downstream parts of the hard floor structure. Therefore, it is possible to effectively cover the undulations of the riverbed, so that local scouring can be effectively prevented, and the flow velocity accelerated by the hard girdle structure can also be reduced.
<B> Not only can the flow rate be reduced and the landscape improved, but also a suitable close-to-natural habitat that takes into account underwater creatures such as juvenile fish and shellfish and waterside plants, and a slow-flow mat acts as a fishway. Therefore, the natural ecosystem can be restored and preserved at an early stage.
< C > It can be used in combination with the optimum floor protection member according to the situation at the site.
[Brief description of the drawings]
FIG. 1 is a perspective view of a structural example of a river bed according to Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram of a structural example of a river bed according to Embodiment 2 using a rod. FIG. 4 is an explanatory diagram of an example of a river bed structure according to a third embodiment combining a flow mat. FIG. 4 is an explanatory diagram of an example of a river bed structure according to another embodiment combining a rod and a slow flow mat. Explanatory drawing of the structural example of the riverbed which concerns on other embodiment which combined 1 type or 2 types of bodies and slow flow mats [FIG. 6] The riverbed which concerns on other embodiments which fixed the slow flow mat using the anchor Illustration of structure example
DESCRIPTION OF SYMBOLS 10 Hard girder structure 20 River bed 30 Slow flow mat 31 Base material 32 Slow flow weight body 33 Surplus length part 40 Body 41 Housing guard 42 Stone 50 Anchor

Claims (5)

It is a structure that protects a river bed having a hard floor structure,
A flexible slow flow mat having both a scouring prevention action, a flow velocity reduction action, and a fishway action, each having a plurality of weights protruding from the upstream and downstream portions of the hard floor structure, respectively.
It is characterized in that it is installed in combination with one or two types of a case containing stones packed with stones in a flexible housing case,
River bed structure.   The river bed according to claim 1, wherein any one of a slow-flow mat and a stone-encased frame is installed in a single combination at an upstream portion and a downstream portion of the hard protection floor structure, respectively. Structure.   The riverbed structure according to claim 1, wherein a slow flow mat and a stone-encased frame are installed as a pair in an upstream portion and a downstream portion of the hard floor structure.   The upstream side and the downstream side of the hard girdle structure are each installed as a pair of a slow flow mat and a stone-containing frame and a combination of the two. River bed structure. A method for protecting a riverbed having a hard glove structure,
In the scouring planned areas of the upstream and downstream parts of the hard floor structure,
A slow flow mat with a plurality of weights protruding from the surface;
It is characterized in that one or two types of stone-containing rod bodies filled with stones are packed in a flexible storage rod and the river bed is covered.
Riverbed protection method.

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