JP2024009736A - River improvement method and river structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a river structure capable of effectively using water in a river.

SOLUTION: A structure provided in a river R and between banks B comprises: a base structure 102 having a floor 102b at a predetermined limit liquid level; a facility structure 110 having an internal hollow space 110h provided at a distance above the base structure 102; a storage tank 105 configured to store water of the river R and provided on a bottom floor LB of a low-water channel LR of the river R upstream of the base structure 102; a supply unit 130 for supplying water in the storage tank 105 to the hollow space 110h of the facility structure 110; a drop channel 140 provided downstream of the facility structure 110 and dropping water in the hollow space 110h of the facility structure 110 to the river R; and a generator 145 provided in the drop channel 140. The storage tank 105 has an inner bottom 105b located below the bottom floor LB of the low-water channel LR of the river R.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a river improvement method and a river structure.

In recent years, river embankments in various places have burst due to huge typhoons and torrential rains, causing extensive damage. Most river embankments have been constructed using various earthen materials since ancient times, and there have been many reported cases of levees breaking due to overflow during floods, seepage within the earthen levees, or erosion.

As a levee reinforcement structure for reinforcing such an existing levee body, a technique described in Patent Document 1 has been developed. The technique of Patent Document 1 is to cover the surface of the embankment body with improved soil made by mixing local earth and sand, cement material, short fiber material, impermeable material, and water that constitute the embankment body or the surrounding ground of the embankment body. It is something that is created.

In addition, Patent Document 2 describes a technology for creating ground around a river by installing sheet piles at a certain distance from the shore, and mixing and solidifying sludge and cement from the river bottom between the sheet piles and the bank. is disclosed.

Further, Patent Document 3 discloses a technique of forming a seawall by stacking and arranging seawall blocks having openings at the top on the surface of an embankment body.

JP2022-062469A Japanese Unexamined Patent Publication No. 48-95043 Utility model registration No. 3118346

However, the techniques of Patent Documents 1 and 2 are only for creating the ground on the surface of the levee body or on the low water channel side relative to the levee body, and the technique of Patent Document 3 is only for constructing the ground on the surface of the levee body or on the low water channel side of the levee body. This is a technology for reinforcing the surface of an embankment body by arranging them, and neither of these technologies is for forming a seawall separately from the existing embankment body. Furthermore, although the techniques disclosed in Patent Documents 1 to 3 can strengthen the existing embankment, they cannot sufficiently prevent flooding, and there is a need for a technique that can more effectively prevent flooding.

In addition, shortages of supplies such as drinking water and electricity occur not only in floods but also in various disasters, and it would be effective if river water could be used as a source of drinking water or electricity during disasters. However, there are insufficient facilities to effectively utilize river water during disasters.

In view of the above circumstances, an object of the present invention is to provide a river structure that can effectively utilize river water.
Another object of the present invention is to provide a river improvement method and river structure that can effectively prevent flooding.

<River structures>
The river structure of the first invention is a structure provided between a river and an embankment, and includes a base structure having a floor surface at a predetermined critical liquid level height, and a structure provided above the base structure. equipment structures provided at intervals and having hollow spaces inside; a storage tank for storing river water provided on the bottom of a low river channel upstream of the base structure; a supply unit that supplies water in the storage tank to the hollow space of the equipment structure; and a falling flow that is provided on the downstream side of the equipment structure and causes the water in the hollow space of the equipment structure to fall into the river. and a generator provided in the falling channel, and the storage tank is characterized in that it has an inner bottom located below the bottom of the low water channel of the river. .
In the river structure of a second aspect of the invention, in the first aspect, the hollow space of the equipment structure includes a water receiving tank in which water supplied from the supply section is stored, and a water tank in which water to be drained to the falling channel is stored. and a water purification facility provided between the water receiving tank and the drainage tank.
A river structure according to a third invention is characterized in that in the first or second invention, a channel space for flowing river water is provided between the base structure and the equipment structure. .
In the river structure of a fourth invention, in the first or second invention, the equipment structure is provided with a ceiling member that covers a hollow space, and the ceiling member is provided with a solar power generation panel. It is characterized by the presence of
In the river structure of the fifth invention, in the first or second invention, on the upstream side of the base structure, the boundary is excavated at the boundary between the low water channel and the high water bed in the river in the direction in which the river flows. It is equipped with a pair of revetment structures consisting of a plurality of revetment boxes installed side by side along the direction of river flow on a flat installation bottom formed along the It is characterized by being filled with dredged earth and sand from the bottom of low-lying channels and sandbars.
<Bank protection structure>
The river structure of the sixth invention is provided with a flat installation bottom formed along the direction of river flow by excavating the boundary between a low water channel and a high water bed in a river. It is equipped with a pair of revetment structures formed by multiple revetment boxes installed side by side, and each revetment box is a hollow box-shaped body filled with dredged earth and sand from the bottom floor of a low channel and sandbars. It is characterized by being something.
A river structure according to a seventh aspect of the present invention, in the sixth aspect, includes a weir structure installed to connect the pair of bank protection structures, and the weir structure connects the plurality of bank protection boxes. It is characterized by being formed by
The river structure according to an eighth aspect of the present invention is characterized in that, in the seventh aspect, the weir structure has a waterway that passes water from upstream to downstream, and a hydroelectric power generation device is installed in the waterway. do.
<River repair method>
The river improvement method according to the ninth invention includes excavating the boundary between a low water channel and a high water bed in a river to form a flat installation bottom along the flowing direction of the river, and opening the formed installation bottom at the upper end. A plurality of hollow revetment boxes with When a predetermined amount of earth and sand is contained in the box, the openings of the plurality of seawall boxes are sealed to form a pair of seawall structures.
In the river improvement method of the tenth invention, in the ninth invention, the floating body on which the dredging equipment is installed is floated on the water of the river, and while the floating body is moved along the flowing direction of the river, the bottom floor of the low water channel and/or The method is characterized by dredging sand from sandbars and putting the dredged sand into multiple seawall boxes.
In the river improvement method according to an eleventh invention, in the tenth invention, the dredging equipment includes a hollow box-shaped dredging container that is raised and lowered through an opening provided in the floating body, and a lifting device that raises and lowers the dredging container. , a suction device for sucking earth and sand in the dredging container, the dredging container is a hollow box-like body whose upper end is closed by a ceiling wall and an opening is formed at the lower end, and the elevating device is , the dredging container has a function of pressing the lower end of the dredging container against the bottom floor of a low waterway and/or sand in a sandbar so that the earth and sand enters the dredging container, and the suction device sucks up the earth and sand from inside the dredging container. It is characterized by supplying earth and sand to a plurality of seawall boxes.
The river improvement method of the twelfth invention is the ninth invention, in which a plurality of hollow revetment boxes are installed side by side so as to cross between the pair of revetment structures, and the bottom floor of the low water channel and/or the earth and sand of the sandbank are removed. The dredged earth and sand are poured into a plurality of revetment boxes, and when a predetermined amount of earth and sand is accommodated in the plurality of revetment boxes, the openings of the plurality of revetment boxes are sealed to form a weir structure. do.

<River structures>
According to the first invention, it becomes easier to effectively utilize river water.
According to the second invention, if river water is purified by the water purification equipment, the river water can be used as drinking water or domestic water. Then, river water can be used effectively in the event of a disaster.
According to the third aspect of the invention, even if the river rises in water, it is possible to generate electricity while preventing damage to equipment structures and the like.
According to the fourth invention, the area where the equipment structure is provided can be effectively used for power generation.
According to the fifth invention, since a pair of bank protection structures formed by arranging a plurality of bank protection boxes are provided at the boundary between a low water channel and a high water bed in a river, the strength of the bank can be increased. Moreover, since the dredged soil of the bottom floor of the low channel and/or the sandbar is stored in the seawall box, the flow of water in the low channel can be improved and the dredged soil can be easily disposed of.
<River structures>
According to the sixth invention, a pair of bank protection structures formed by arranging a plurality of bank protection boxes are provided at the boundary between a low water channel and a high water bed in a river, so that the strength of the bank can be increased. Moreover, since the dredged soil of the bottom floor of the low channel and/or the sandbar is stored in the seawall box, the flow of water in the low channel can be improved and the dredged soil can be easily disposed of.
According to the seventh and eighth inventions, since the weir structure is installed, the use of river water can be promoted.
<River repair method>
According to the ninth invention, a plurality of revetment boxes are arranged at the boundary between a low water channel and a high water bed in a river to form a pair of revetment structures, so the strength of the embankment can be increased. Moreover, since the dredged soil of the bottom floor of the low channel and/or the sandbar is stored in the seawall box, the flow of water in the low channel can be improved and the dredged soil can be easily disposed of.
According to the tenth invention, it is possible to effectively dredge the bottom floor of a low water channel and/or the earth and sand of a sandbank, and it is also possible to efficiently install a plurality of revetment boxes.
According to the eleventh invention, it is possible to effectively dredge the bottom floor of a low water channel and/or the earth and sand of a sandbar.
According to the twelfth invention, since a weir is installed, the use of river water can be promoted.

(A) is a schematic sectional view of the river R provided with the bank protection structure 1 of this embodiment, and (B) is a schematic plan view of the river R provided with the bank protection structure 1 of this embodiment. It is a schematic work diagram of the river improvement method of this embodiment. (A) is a schematic front view of the dredging device 30, and (B) is a schematic plan view of the dredging device 30. (A) is a schematic cross-sectional view of a river R provided with a revetment structure 1 of this embodiment having a weir structure 3, and (B) is a schematic cross-sectional view of a river R provided with a revetment structure 1 of this embodiment having a weir structure 3. It is a schematic plan view of river R. (C) is a schematic cross-sectional view of the weir structure 3. (A) is a schematic front view of the dredging device 30 having a container 41 inside the dredging container 33, and (B) is a sectional view taken along the line BB of the dredging device 30 having the container 41 inside the dredging container 33. It is a schematic front view of the dredging device 30 in a state in which a crushing device 43g is provided in a container 41 and a pipe 36 is fixed. It is a schematic plan view of a river R provided with a river structure 100 of this embodiment. It is a schematic plan view of the river R provided with the river structure 100 of this embodiment, Comprising: It is a schematic explanatory drawing of the state with the ceiling member 110c removed. It is a schematic vertical cross-sectional view of a river R provided with a river structure 100 of this embodiment. It is a schematic plan view of the river R provided with the river structure 100 of other embodiments, and is a schematic explanatory view with the ceiling member 110c removed. It is a schematic longitudinal cross-sectional view of the river R in which the river structure 100 of other embodiments was provided.

The river repair method of this embodiment can prevent river flooding and make effective use of sand and the like in the river.

<River structure>
First, before explaining the river improvement method of this embodiment, the structure of the river to which the river improvement method of this embodiment is applied will be explained.

As shown in FIG. 2(A), a river R to which the river improvement method of the present embodiment is applied has a low water channel LR, a high water bed HR, and an embankment B.
The low channel LR is a channel where water always flows, and the high water bed HR is a channel that is one step higher than the low channel LR. This is the region where W flows.
Embankment B is designed to allow water W to flow safely when the water level is below the planned high water level. In the river improvement method of this embodiment described below, there is a possibility that the width of the low waterway LR will be narrowed, but even if the amount of water that reaches the planned high water level in the river R before the improvement flows into the river R after the improvement, the planned high water level will be reduced. The water level is designed to remain almost constant.

<River repair method of this embodiment>
The river repair method of this embodiment is a method of repairing a river R having a structure as shown in FIG. 2(A). In other words, this is a modification method for modifying a river R having a structure as shown in FIG. 2(A) into a river R having a bank protection structure 1 as shown in FIG.

<Bank protection structure 1>
As shown in FIG. 1, the revetment structure 1 includes a pair of revetment walls 2 formed by arranging a plurality of revetment boxes 10 at the boundary between the low water channel LR and the high water bed HR. That is, a pair of revetment walls 2, 2 are provided so as to sandwich the low waterway LR from a direction intersecting the direction in which water W flows (hereinafter sometimes referred to as flow path direction D).

Each of the revetment boxes 10 constituting the revetment wall 2 stores soil dredged from the bottom bed LB of the low water channel LR and/or the sand of the Nakasu SD in the repair method described below. It is installed on an installation bottom SB (hereinafter sometimes simply referred to as installation bottom SB) formed on the bottom floor LB of the low water channel LR in the boundary portion.

The seawall box 10 is a rectangular parallelepiped with a hollow space inside, and is formed by, for example, connecting iron plates made of metal such as stainless steel by welding or the like. For example, the seawall box 10 is made by connecting stainless steel plates with a thickness of 2 to 3 mm, and has a height of 3 to 8 m (preferably 5 to 6 m), a depth of 2 to 5 m (preferably 3 to 5 m), and a width of 3 to 8 m (preferably 5 to 6 m). The length is 2 to 6 m (preferably 5 to 6 m).

The seawall box 10 is formed by closing an opening 11a of a bottomed rectangular cylindrical main body 11 with a lid member 12 having an opening at the upper end. Specifically, the seawall box 10 is formed by pouring earth and sand into a hollow space 11h through an opening 11a, and then attaching the lid member 12 to the opening 11a of the main body 11 by a method such as welding. (See Figure 1(A)). That is, the seawall box 10 is completed after being installed on the installation bottom SB formed on the bottom floor LB of the low waterway LR.

The pair of revetment walls 2, 2 is formed by connecting a plurality of revetment boxes 10. Specifically, after a plurality of revetment boxes 10 are arranged so as to line up on the installation bottom SB along the flow path direction D, a pair of revetment walls 2, 2 are formed by connecting adjacent revetment boxes 10. has been done.

<About river improvement methods>
A method of forming the seawall structure 1 having the pair of seawall walls 2, 2 as described above will be described below.

First, at the boundary between the low water channel LR and the high water bed HR where the revetment box 10 is installed, excavation is carried out so that the bottom floor LB of the low water channel LR is brought close to horizontal, thereby forming the installation bottom SB (Fig. 2 (B) reference). The installation bottom SB is formed along the flow path direction D by a predetermined length (for example, 1 km, etc.).

Once the installation bottom SB is formed, the main body parts 11 of the seawall box 10 are installed side by side in the entire area where the installation bottom SB is provided along the length direction of the installation bottom SB (that is, the flow path direction D). At this time, the main bodies 11 of the seawall boxes 10 are installed side by side so that the openings 11a thereof face upward (see FIG. 2(C)).

When the main bodies 11 of the revetment boxes 10 are installed on the installation bottom SB, the main bodies 11 of the adjacent revetment boxes 10 are connected to each other by welding, bolting, or the like to form a row of revetment boxes. When the seawall box row is formed, the dredging device 30 equipped with the dredging device 32 on the floating body 31 is floated on the water W of the river R to dredge the earth and sand of the bottom bed LB of the low channel LR and/or the sandbank SD ( (See Figure 2(C)). Then, the dredged earth and sand is thrown into the spaces 11h of the main bodies 11 of the plurality of seawall boxes 10 by the dredging equipment 32 of the dredging device 30.

By carrying out the above-mentioned work while moving the dredging device 30 along the flowing direction of the river R, the dredged earth and sand is removed by the dredging device 32 into the space 11h of the main body portion 1111 of the plurality of revetment boxes 10 in the revetment box row. throw into. Note that "carrying out the above work while moving the dredging device 30 along the flowing direction of the river R" refers to the dredging work or the work of injecting earth and sand into the space 11h of the main body 11 while moving the dredging device 30. This includes both cases in which the dredging device 30 is stopped during dredging work and work to introduce earth and sand into the space 11h of the main body portion 11.

When the earth and sand are put into the spaces 11h of the main body parts 11 of all the seawall boxes 10 forming the seawall box row, the lid member 12 is placed in the opening 11a of the main body part 11 to connect the lid member 12 and the main body part 11. , the space 11h of the main body portion 11 is sealed by the lid member 12. The lid member 12 and the main body portion 11 are connected by welding. For example, a welding machine that moves along the embankment B of the river R is provided, and this welding machine connects the lid members 12 and main bodies 11 of all the revetment boxes 10 to seal all the revetment boxes 10 in the row of revetment boxes. Then, the seawall 2 will be completed. If the revetment walls 2 are formed on both banks, the revetment structure 1 can be formed over a predetermined length along the channel direction D (see FIG. 2(D)).

If the revetment structure 1 is formed using the method described above, the bottom bed LB of the low water channel LR and the earth and sand of the sandbank SD can be removed from the low water channel LR, so the water flow of the river R can be maintained in a stable state. This will make it easier to suppress flooding of River R.

In addition, since the earth and sand removed from the bottom floor LB of the low channel LR and the sandbank SD can be stored in the seawall box 10 that constitutes the seawall 2, it becomes easy to dispose of the earth and sand, and the removed earth and sand can be stored. It can be effectively used for seawalls.

Furthermore, if the bank protection box 10 that accommodates the earth and sand is made of metal with high corrosion resistance, the boundary between the low water channel LR and the high water bed HR can be strengthened over a long period of time, so the strength of the river R can be increased over a long period of time. Note that as long as the part is constantly submerged in water, it does not need to be made of highly corrosion-resistant metal, and may be formed of a general steel plate.

In addition, in the river R where the revetment structure 1 was formed, a pair of revetment walls 2, 2 are installed and the bottom floor LB of the low water channel LR is dredged, so that the part where water normally flows, that is, the low water channel LR, is dredged. The width of the corresponding portion becomes narrower than the width of the original low water channel LR, and the depth of the low water channel LR becomes deeper than the depth of the original low water channel LR. For example, in the river R that formed the seawall structure 1, the width of the part corresponding to the low water channel LR can be set to about 1/2 of the width of the original low water channel LR, and the depth of the part corresponding to the low water channel LR The depth can be approximately 3 to 6 times the depth of the original low water channel LR. In addition, in the river R in which the bank protection structure 1 was formed, the width and depth of the portion corresponding to the low water channel LR are not limited to the above ranges, and may be appropriately adjusted depending on the state of the river R and the like.

<About fixing the seawall box 10>
Among the plurality of seawall boxes 10, adjacent seawall boxes 10 are connected to each other by welding, bolting, or the like, but the method for connecting the adjacent seawall boxes 10 is not particularly limited.

In addition, each revetment box 10 stores earth and sand, and one revetment box 10 contains several tons or more, so if multiple revetment boxes 10 are connected, it is not necessary to store the revetment box 10 at the bottom of the low water channel LR. It is not necessary to fix it to the floor LB with stakes or the like. However, in order to increase the stability of the pair of revetment walls 2, 2, it is necessary to fix all or some of the revetment boxes 10 to the bottom floor LB of the low channel LR with stakes or the like. It is desirable to keep it.

<About the shape of the seawall box 10>
The size of the seawall box 10 is not limited to the size described above. The size of the revetment box 10 is determined to be an appropriate size according to the size and shape of the river R that forms the pair of revetment walls 2, 2 by the revetment box 10 (for example, the size of the step between the low channel LR and the high water bed HR). Just form it.

Moreover, the shape of the seawall box 10 is not limited to the shape mentioned above. For example, the seawall box 10 may have a polygonal cross section such as a triangle or a pentagon, or may have a circular cross section. Moreover, the seawall box 10 is not limited to a rectangular parallelepiped, but may be a cube. The revetment box 10 may be formed into an appropriate size and shape according to the state of the river R forming the pair of revetment walls 2, 2. In addition, the seawall boxes 10 preferably have flat sides in order to strengthen the connection between adjacent seawall boxes 10. In other words, it is desirable that the seawall boxes 10 have flat surfaces where adjacent seawall boxes 10 come into contact with each other.

Moreover, the revetment boxes 10 forming the pair of revetment walls 2, 2 do not have to be all of the same size and shape. Depending on the size and shape of the river R (for example, the size of the step between the low water channel LR and the high water bed HR), bank protection boxes 10 of different shapes and sizes may be used as appropriate.

<Dredging device 30>
The dredging device 30 may have any structure as long as it can dredge the bottom bed LB of the low waterway LR and/or the earth and sand of the sandbank SD. A dredging machine that can move in the embankment B or high water bed HR, or a dredging machine that can move in the low water channel LR, such as a GNSS compatible mini excavator car, etc. can be used as the dredging device 30. However, as described above, if the dredging device 30 is constructed by providing the dredging device 32 on the floating body 31 so that it can be moved while floating on the water W of the river R, the dredging device 30 can be moved easily and at a low cost. The work of removing earth and sand from the bottom bed LB of the waterway LR and/or the sandbank SD can be carried out efficiently.

In this case, the structure of the floating body 31 is not particularly limited, as long as it has a structure that allows the dredging work to be carried out stably even when the dredging equipment 32 is placed thereon. For example, the floating body 31 may have a hollow plate-like structure made of stainless steel or the like, as long as it has a sufficiently large area and a volume capable of generating sufficient buoyancy (see FIG. 3). Alternatively, the floating body 31 may be formed by connecting a plurality of hollow box-like bodies that can be connected and separated.

The dredging device 32 provided on the floating body 31 may be, for example, a GNSS-compatible mini excavator, or a device as shown in FIG. 3 may be used. As shown in FIG. 3, an opening 31h penetrating vertically is provided in the center of the floating body 31, and a dredging container 33 that can be inserted through the opening 31h, a lifting device 34 that raises and lowers the dredging container 33 up and down, and a dredging container 33 that can be inserted through the opening 31h. The dredging equipment 32 includes a suction device 35 such as a pump that suctions the inside of the container 33. In this case, the dredging container 33 is a hollow box-shaped body surrounded by a ceiling wall 33b and side walls 33c and having an opening 33a at the lower end. Although not shown, the lifting device 34 is provided with a function of generating an urging force to press the dredging container 33 downward. Note that a through hole 33h is provided in the ceiling wall 33b of the dredging container 33, and a pipe 36 such as a pipe of a suction device 35 is connected to this through hole 33h. In other words, the suction device 35 is configured to be able to suction the object inside the dredging container 33 through the through hole 33h.

When using such dredging equipment 32, the earth and sand of the bottom bed LB of the low waterway LR and/or the sandbank SD can be dredged as follows.

First, the movement of the dredging device 30 is stopped with the opening 31h of the floating body 31 placed above the earth and sand to be dredged. In this state, the dredging container 33 is lowered by the lifting device 34. When the lower end of the dredging container 33 is placed on the upper surface of the earth and sand, the lifting device 34 pushes the dredging container 33 downward, and the lower end of the dredging container 33 is pushed into the earth and sand. When the suction device 35 is operated in this state, the suction device 35 sucks in the earth and sand, so that the earth and sand can be removed from the bottom floor LB of the low water channel LR and/or the sandbank SD. If the pipe 37 for discharging the earth and sand sucked in by the suction device 35 is arranged in the space 11h of the main body 11 of the seawall box 10, the earth and sand can be supplied into the space 11h of the main body 11 of the seawall box 10. (See Figure 2(C)).

Note that if the dredging container 33 is to be stably raised and lowered through the opening 31h of the floating body 31, it is desirable to provide the floating body 31 with a guide rail for guiding the movement of the dredging container 33. For example, a rail may be provided that extends vertically from the opening 31h of the floating body 31, and the dredging container 33 may be moved up and down along the rail.

<Dredging equipment 40>
Further, a dredging device 40 that scoops earth and sand in the dredging container 33 may be provided in the dredging container 33. If the dredging equipment 40 is provided with a container 41 and the container 41 is used to scoop up earth, sand, stones, etc., stones and the like that cannot be sucked into the pipe 36 can be scooped out and removed.

For example, as shown in FIG. 5, the container 41 includes a bottom plate 41b, a pair of side plates 41s, 41s provided on the side surfaces of the bottom plate 41b, and a partition plate 41d connecting the pair of side plates 41s, 41s. Provide what you have. That is, the container 41 is provided with its upper and both ends (ends in the left and right direction in FIG. 5) open. Then, the container 41 can be moved along the left-right direction (in the direction of arrow X in FIG. 5) using a wire 42 or the like. Then, by moving the container 41 in the direction of arrow X, stones and earth and sand can be scooped into the container 41 through the openings 41a provided at both ends of the container 41.

When such dredging equipment 40 is provided, a dredging container 33 having a structure without a ceiling wall 33b is used. Then, if the container 41 is made to be able to be moved up and down within the dredging container 33, when stones or the like that cannot be sucked into the piping 36 are scooped up, the container 41 can be moved to a position where its opening 41a is above the upper end of the dredging container 33. If the floating body 31 is raised until the floating body 31 is lifted, stones and the like that cannot be sucked into the piping 36 can be discharged onto the floating body 31. Then, stones and the like can be thrown into the space 11h of the main body part 11 of the seawall box 10 from above the floating body 31 or transported to another location using heavy machinery or the like. Furthermore, stones and the like can be directly removed from the top of the container 41 using heavy equipment and placed into the space 11h of the main body 11 of the floating revetment box 10, or transported to another location.

Furthermore, if the pipe 36 can be fixed to the container 41, the pipe 36 can suck up earth and sand from the bottom floor LB of the low water channel LR and Nakasu SD, from which stones and the like that cannot be sucked into the pipe 36 have been removed (Fig. (see 6). Since the pipe 36 is fixed to the container 41, the position of the tip of the pipe 36 within the dredging container 33 can be freely adjusted by moving the container 41. Then, the earth and sand in the dredging container 33 can be reliably sucked up.

Further, the container 41 may be provided with a crushing device 43g such as a pick hammer or a concrete breaker (see FIG. 6). In this case, the tip of the crushing device 43g is made to protrude from the lower surface of the bottom plate 41b of the container 41. Then, by moving the container 41 downward and operating the crushing device 43g with the tip of the crushing device 43g in contact with the bottom floor LB of the low water channel LR and the sand and rocks of the Nakasu SD, the bottom bed of the low water channel LR It can crush the earth, sand and rocks of LB and Nakasu SD. In this case, if the pipe 36 is fixed to the container 41, crushed stones and the like can be sucked up by the pipe 36. Of course, after crushing the soil and rocks on the bottom floor LB of the low channel LR and the Nakasu SD, the container 41 is raised once and the piping 36 is fixed to the container 41, and then the container 41 is moved to remove the crushed stones, etc. A piping 36 may be placed at the position and suction may be taken up by the piping 36.

Further, the container 41 may be fixed within the dredging container 33 instead of being movable. Even in this case, if the dredging device 30 itself is moved, stones and earth and sand can be scooped out using the container 41.

Furthermore, the container 41 may be provided with the above-mentioned pick hammer, concrete breaker, or the like. In this case, if the tip of a pick hammer, concrete breaker, etc. is made to protrude from the bottom surface of the bottom plate 41b of the container 41, the bottom floor LB of the low water channel LR and the sandbank SD can be crushed, and the crushed stones, earth, etc. can be removed by the container 41. You can also scoop it.

Further, a container 41 may be provided separately from the dredging container 33. Even in this case, the container 41 may be provided movably relative to the floating body 31 and the container 41 may be moved using a wire 42 or the like, or the container 41 may be fixed to the dredging device 30 but the dredging device 30 itself may be moved. , stones and dirt can be scooped out by the container 41.

Furthermore, a floating body separate from the floating body 31 provided with the dredging container 33 and the suction device 35 may be provided, and the container 40 may be provided on this floating body.

Further, it is preferable that the elevating device 34 has a frame 34F having a rail that holds the dredging container 33 and guides the lifting and lowering of the dredging container 33. With such a frame 34F, the dredging container 33 can be stably raised and lowered. Further, when the dredging container 33 has the crushing device 43g, the weight of the dredging container 33 increases, but even in that case, the dredging container 33 can be stably held.

Further, it is desirable that each device constituting the dredging device 32 be electrically operated. With this configuration, if a solar power generation device is provided on the floating body 31, the power source can be supplied from the solar power generation device, so that the river R can be repaired with energy savings.

<About the installation of weir 3>
Since the river R flows with a difference in height between upstream and downstream, if the installation bottom SB is formed horizontally for a certain distance and a pair of revetment walls 2, 2 are formed on it, the revetment box 10 is formed on the upstream and downstream sides. The relative height between the water level and the water level of the water W in the low water channel LR changes. For example, in the case of a river with a gradient of 0.1%, a height difference of 1 m occurs in 1 km, so there is a possibility that the pair of revetment walls 2, 2 may not be able to perform a sufficient revetment function on the upstream side.

Therefore, the weir structure 3 may be installed so as to connect the pair of seawalls 2, 2. Specifically, the weir structure 3 may be formed by installing a structure similar to the revetment box 10 used for the pair of revetment walls 2, 2 side by side between the pair of revetment walls 2, 2. Note that, hereinafter, the seawall box forming the weir structure 3 will be referred to as a weir box 20.

The weir box 20 has the same structure as the revetment box 10, and is a rectangular parallelepiped with a hollow space inside, and is formed by, for example, connecting iron plates made of metal such as stainless steel by welding or the like. be. The weir box 20 is, for example, made by connecting stainless steel plates with a thickness of 2 to 3 mm, and has a height of 3 to 8 m (preferably 5 to 6 m), a depth of 2 to 5 m (preferably 3 to 5 m), and a width equal to the height. The length is 2 to 6 m (preferably 5 to 6 m).

Like the bank protection box 10, this weir box 20 is also formed by closing an opening 21a of a bottomed rectangular cylindrical main body portion 21 with a lid member 22 having an opening at the upper end. Specifically, the weir box 20 is formed by putting earth and sand into the hollow space 21h through the opening 21a, and then attaching the lid member 22 to the opening 21h of the main body part 21 by a method such as welding ( (See Figure 4(C)). That is, the weir box 20 is also installed between the pair of revetment walls 2, 2, and then completed.

In addition, at the location where the weir box 20 is installed, an installation surface EB is formed so as to connect the pair of revetment walls 2, 2 (see FIG. 4(A)).

The weir box 20 forming the weir structure 3 and the revetment box 10 adjacent to the weir structure 3 on the pair of revetment walls 2, 2 are connected by a method such as welding so that there is no gap between them. Ru.

<About how to install weir structure 3>
The weir structure 3 as described above can be formed in the same manner as the pair of revetment walls 2, 2. Note that the pair of revetment walls 2, 2 can be installed even when the water W is flowing into the river R, but when forming the weir structure 3, the work should be carried out after damming the water W upstream of the installation location. be exposed.

First, an installation surface EB is formed in the area where the weir box 20 is to be installed, and once the installation surface EB is formed, the main body parts 21 of the weir box 20 are installed side by side over the entire area where the installation surface EB is provided. At this time, the main bodies 21 of the weir boxes 20 are installed side by side so that the openings 21a thereof face upward (see FIG. 4(C)). Then, all or some of the plurality of weir boxes 20 are fixed to the installation surface EB with stakes or the like.

When the weir boxes 20 are fixed to the installation surface EB, the main bodies 21 of adjacent weir boxes 20 are connected to each other by welding, bolting, or the like to form a weir box row. When the weir box row is formed, the dredging device 30 dredges the earth and sand of the bottom bed LB of the low water channel LR and/or the sand bar SD. Then, the dredged earth and sand is thrown into the spaces 21h of the main bodies 21 of the plurality of weir boxes 20 by the dredging device 30.

When earth and sand are poured into the spaces 21h of the main bodies 21 of all the weir boxes 20 forming the weir box row, the lid member 22 is placed in the opening 21a of the main body 21 to connect the lid member 22 and the main body 21. , the space 21h of the main body portion 21 is sealed by the lid member 22. Then, by sealing all the weir boxes 20 with the lid members 22, the weir structure 3 is completed.

<About fixing the weir box 20>
Among the plurality of weir boxes 20, adjacent weir boxes 20 are connected to each other by a method such as welding or bolting, but the method of connecting adjacent weir boxes 20 to each other is not particularly limited.

<About the shape of the weir box 20>
The size of the weir box 20 is not limited to the size described above. The size of the weir box 20 may be appropriately formed according to the size and shape of the river R forming the weir structure 3 by the weir box 20.

Furthermore, the shape of the weir box 20 is not limited to the above-mentioned shape. The weir box 20 may have a polygonal cross section such as a triangle or a pentagon, but it is preferable that the side surface be flat, like the seawall box 10.

Moreover, the weir boxes 20 forming the weir structure 3 do not have to be all the same size or the same shape. Weir boxes 20 of different shapes and sizes may be used as appropriate depending on the shape required for the weir structure 3 to be formed.

<About weir structure 3>
The weir structure 3 may be provided with various types of equipment.
For example, a waterway may be provided in a part of the weir structure 3 to allow water W to pass from upstream to downstream. When such a waterway is provided, a fish ladder through which fish can pass may be provided in the waterway. Furthermore, if a large head difference is provided in the waterway before and after the weir structure 3, it is possible to generate electricity by installing a hydroelectric power generation device in the waterway.

<About the location where weir structure 3 is installed>
The position where the weir structure 3 is installed is not particularly limited. However, when installing the above-mentioned hydroelectric power generation device, it is preferable to install it at a position where the difference in height of the bottom floor LB of the low water channel LR between adjacent weir structures 3 is at least 1 m. Specifically, it is desirable to install the weir structures 3 so that the riverbed gradient I between adjacent weir structures 3 is greater than I=1/100.

<About the river structure 100>
As shown in FIGS. 7 and 8, the following river structure 100 is installed in a river R where a revetment structure 1 having a pair of revetment walls 2, 2 formed by a plurality of revetment boxes 10 is installed. If established, it will be possible to supply the necessary purified water and electricity in the event of a disaster.

<Body structure 101>
As shown in FIG. 9, the river structure 100 has a main structure 101 having a base structure 102 and an equipment structure 110. This main body structure 101 is provided so as to connect the pair of embankments B and B (see FIGS. 7 and 8). Moreover, the main body structure 101 is provided so that the pair of revetment walls 2, 2 are located on the upstream side and the downstream side in the flowing direction of the river R. That is, the main body structure 101 is installed so as to be sandwiched between the pair of revetment walls 2, 2 in the flowing direction of the river R.

<Base structure 102>
As shown in FIG. 9, the base structure 102 of the main body structure 101 is provided to support the equipment structure 110. This base structure 102 is a foundation made of concrete, for example, provided in the river R, and is a structure whose upper surface, that is, the floor surface 102b, is formed substantially horizontally or substantially parallel to the slope of the river R. The floor surface 102b of the base structure 102 is formed to be approximately at the same height as the maximum liquid level at which water flows between the pair of revetment walls 2, 2 under normal conditions. In other words, when a normal amount of water is flowing between the pair of revetment walls 2, 2, the water in the waterway between the pair of revetment walls 2, 2 is dammed up by the base structure 102. A base structure 102 is provided.

Note that the base structure 102 may be made of any material as long as it can stably support the equipment structure 110, and is not limited to being made of concrete, but may be made of steel or the like.

<Equipment structure 110>
As shown in FIG. 9, an equipment structure 110 is installed above this base structure 102. Specifically, the equipment structure 110 is installed such that a flow path space 101h is formed between the lower surface 110b of the equipment structure 110 and the floor surface 102b of the base structure 102. For example, the height of the lower surface 110b of the equipment structure 110 is set to be slightly higher than the planned high water level of river R, but the height of the lower surface 110b of the equipment structure 110 is set to be slightly higher than the planned high water level. It is not particularly limited as long as it is high. The equipment structure 110 is supported by a plurality of pillars 103 erected on the base structure 102. The plurality of columns 103 are made of reinforced concrete or steel, for example. Note that, as described later, the plurality of columns 103 have the strength to stably support the equipment structure 110 even when the maximum amount of water is stored inside the equipment structure 110. The structure is not particularly limited.

As shown in FIG. 8, the equipment structure 110 is a structure having a hollow space 110h inside. Specifically, the equipment structure 110 has a structure that can store water inside. In other words, when water is stored in the hollow space 110h of the equipment structure 110, the structure is such that the water does not leak. A hollow space 110h of this equipment structure 110 is liquid-tightly divided into a water receiving tank 111, an equipment installation space 112, and a drainage tank 113 from the upstream side by separation walls 110c and 110d.

<Water tank 111>
The water tank 111 is a space for storing water supplied from a supply unit 130, which will be described later. The water receiving tank 111 is connected to the water pump 135 of the supply section 130 through a pipe 135p, and the water in the storage tank 105 is supplied by the water pump 135 of the supply section 130.

<Equipment installation space 112>
The equipment installation space 112 is a space in which a purification equipment 115 that purifies the water in the water receiving tank 111 and supplies it to the drainage tank 113 is provided. The purification equipment 115 is connected to the water receiving tank 111 through a pipe or the like, which has one end connected to the water receiving tank 111 and the other end connected to a water intake port of the purification equipment 115, and one end connected to an outlet of the purification equipment 115. The other end is connected to the drainage tank 113 through a pipe or the like connected to the drainage tank 113.

Note that the purification equipment 115 installed in the equipment installation space 112 is not particularly limited. For example, water purification equipment such as CPCM2 manufactured by Meta Water Co., Ltd. can be used as the purification equipment 115. Further, the number of purification equipment 115 to be installed is not particularly limited, and the number may be provided as required depending on the amount of water to be treated.

<Drain tank 113>
The drainage tank 113 is a space to which purified water purified by the purification equipment 115 is supplied. The upstream end of a drop channel 140 is communicated with this drain tank 113 so that the water in the drain tank 113 can be dropped downstream of the main structure 101 through the drop channel 140. It has become. A generator 145 is provided in this falling channel 140 . In other words, it has a function of generating electricity by passing the water in the drainage tank 113 through the falling channel 140. Note that the water that has passed through the generator 145 can be supplied to various facilities such as homes and factories via piping etc. that are communicated with the falling flow path 140.

Note that the generator 145 installed in the falling channel 140 is not particularly limited. For example, an underwater turbine generator manufactured by Imuru Kogyo Co., Ltd. or the like can be used as the generator 145.

<Supply section 130>
As shown in FIGS. 7 to 9, a storage tank 105 is provided on the upstream side of the equipment structure 110, which is formed by excavating the bottom bed LB of the low water channel LR. This storage tank 105 is a space formed such that its inner bottom surface 105b is lower than the bottom floor LB of the low water channel LR on the upstream side of the storage tank 105. A plurality of water pumps 135 are provided in the space within this storage tank 105. As described above, one end of the pipe 135p is connected to the drain port of the water pump 135, and the other end of the pipe 135p is connected to the water receiving tank 111. Therefore, by operating the water pump 135, the water in the storage tank 105 can be supplied to the water receiving tank 111.

Note that the water pump 135 is not particularly limited as long as it can supply the water in the storage tank 105 to the water receiving tank 111. For example, a centrifugal pump (model: FBW-500-2, etc.) manufactured by Naniwa Pump Manufacturing Co., Ltd. can be used as the water pump 135.

<Solar power generation equipment 116>
As shown in FIG. 7, the equipment structure 110 is provided with a ceiling member 110c so as to cover the above-mentioned hollow space 110h, and a solar power generation panel of a solar power generation equipment 116 is provided on the upper surface of this ceiling member 110c. 116p is provided. The solar power generation equipment 116 includes a power storage device 116b that stores the power generated by the solar power generation panel 116p, and supplies the generated power to the power storage device 116b for storage or to other equipment (purification equipment 115, water pump 135, etc.). It is equipped with a controller 116c that supplies the information (see FIG. 8).

Note that the controller 116c may have not only a function of controlling the supply of electric power generated by the solar power generation equipment 116, but also a function of controlling the supply of electric power generated by the generator 145. Of course, a controller that controls the supply of power generated by the generator 145 may be provided separately from the controller 116c, and a capacitor that stores the power generated by the generator 145 may also be provided separately from the capacitor 116b. .

If the river structure 100 as described above is provided, water in the river R can be purified and made into drinking water, so that necessary drinks can be obtained from the river R in the event of a disaster.

Furthermore, the solar power generation equipment 116 and the generator 145 can also supply power in the event of a disaster.

Furthermore, if the water volume of the river R is higher than or equal to the maximum liquid level that allows water to flow between the pair of revetment walls 2 and 2 under normal conditions and is lower than the critical liquid level, even if the water volume of the river R increases, , water can flow into the space (flow path space 101h) between the lower surface 110b of the equipment structure 110 and the floor surface 102b of the base structure 102. Then, even if the water in the river R increases and the amount of water exceeds the throughput of the plurality of water pumps 135, water purification and power generation in the river structure 100 can be maintained without damaging the river structure 100.

<About the main body structure 101>
The size of the main body structure 101 is not particularly limited, and may be formed to an appropriate size according to the size of the river R. If the river R has a width of 100 m between the embankments B, the main structure 101 has a width of 100 m in plan view (the length in the vertical direction in FIGS. 7 and 8), and the flow path of the river R. The length along the direction D can be 200 m. Further, the height of the hollow space 110h of the equipment structure 110 is not particularly limited, and may be set to a depth that can store an appropriate amount of water. The height of the hollow space 110h of the equipment structure 110 can be, for example, 5 to 6 m.

The pair of revetment walls 2, 2 do not necessarily need to be provided on the upstream and downstream sides of the main structure 101. It may be provided only on the upstream side of the main body structure 101. However, if it is provided on the downstream side of the main body structure 101, it will be easier to provide a head difference when water is discharged downstream, and it will be easier to generate electricity.

Furthermore, in the equipment structure 110, if the ceiling member 110c is provided so as to cover the hollow space 110h as described above, various devices other than the solar power generation panel 116p can be provided on the upper surface of the ceiling member 110c. can. However, if equipment such as the purification equipment 115 is not provided in the equipment installation space 112, the ceiling member 110c may not necessarily be provided.

Moreover, the water in the water receiving tank 111 does not necessarily have to be supplied to the drainage tank 113 through the purification equipment 115 or the like in the equipment installation space 112. For example, if the water in the water tank 111 is not purified, the water in the water tank 111 may be directly supplied from the water tank 111 to the drain tank 113. For example, a bypass flow path connecting the water tank 111 and the drain tank 113 may be provided to directly supply water from the water tank 111 to the drain tank 113.

When the purification equipment 115 is provided, the purified water may be directly supplied to the outside without being supplied to the drainage tank 113. In this case, it is preferable that a part of the water in the water receiving tank 111 be directly supplied from the water receiving tank 111 to the drain tank 113 by providing a bypass channel or the like.

<About the supply section 130>
The number of water pumps 135 to be provided is not particularly limited, and may be an appropriate number depending on the capacity of the water tank 111, and may be one or more. Further, when providing a plurality of water pumps 135, a storage tank 105 corresponding to each water pump 135 may be provided, or a plurality of storage tanks 105 in which a plurality of water pumps 135 are arranged may be provided. , all the water pumps 135 may be arranged in one storage tank 105. If multiple storage tanks 105 are provided,

Moreover, although the supply part 130 does not necessarily need to be provided, if the supply part 130 is provided, the water supply port of the water pump 135 can be reliably arranged underwater. In other words, even if the water level of the river R falls, the water supply port of the water pump 135 can be easily prevented from being exposed.

Further, the size of the storage tank 105 is not particularly limited either, as long as it is formed to an appropriate size according to the size of the river R. If the river R has a width of 100 m between the embankments B, the main structure 101 has, for example, a width of 50 m in plan view (length in the vertical direction in FIGS. 7 and 8) and a flow path of the river R. It can be formed to have a length of 30 m along direction D. Further, the depth of the storage tank 105 is not particularly limited, and may be set to a depth that can store an appropriate amount of water. The difference in height between the bottom floor LB of the low water channel LR and the inner bottom surface 105b of the storage tank 105 can be, for example, 4 to 8 m.

Furthermore, if the head of the supply section 130, that is, the difference in height between the bottom floor LB of the upstream low water channel LR of the storage tank 105 and the inner bottom surface 105b of the storage tank 105 is increased to a certain extent (for example, about 8 m), the storage tank It also becomes possible to utilize the water flow flowing into 105 for power generation. For example, a pipe that communicates between the bottom floor LB of the low water channel LR on the upstream side of the storage tank 105 and the inner bottom surface 105b of the storage tank 105 is provided at the upstream end of the storage tank 105, and this pipe is used to generate electricity. If a storage tank 105 is provided, the water flow flowing into the storage tank 105 can also be used for power generation. The generator used in this case is not particularly limited, and the same generator as the generator 145 described above can be used.

In particular, when a generator is provided in the storage tank 105, the storage tank 105 is provided with a wall surface 105w extending above the bottom floor LB of the low water channel LR, and a ceiling wall 105c that covers the space surrounded by the wall surface 105w. A pipe 105p penetrating the wall surface 105w may be provided in a space surrounded by the wall surface 105w and the ceiling wall 105c, and water may be supplied through the pipe 105p (FIGS. 10 and 11). In addition, in FIG. 10, the ceiling wall 105c is removed in order to make the structure easier to understand. In this case, if a generator 146 is provided in the pipe 105p, it is also possible to generate electricity using the difference in height between the bottom floor LB of the low water channel LR and the inner bottom surface 105b of the storage tank 105.

<About the falling channel 140 and the generator 145>
A plurality of falling channels 140 may be provided, or one location may be provided. An appropriate number may be provided depending on the capacity of the drainage tank 113 and the amount of power generated by the generator 145. Further, when a plurality of falling channels 140 are provided, an electromagnetic valve or the like may be provided in the falling channels 140 to adjust the falling channels 140 through which water flows. That is, water may be allowed to flow through all of the falling channels 140, or may be allowed to flow through some of the falling channels 140. It may be adjusted appropriately depending on the situation of the river R, the state of water in the drainage tank 113, etc. Further, the generators 145 may be provided in all of the falling channels 140, or may be provided in only some of the falling channels 140.

Further, as shown in FIGS. 9 and 11, an enclosure having a side wall 140b and a ceiling wall 140c may be provided to surround the falling channel 140 and the generator 145 (in addition, FIGS. 7, 8, 10, the ceiling wall 140c is excluded in order to make the structure easier to understand.) That is, the falling channel 140 and the generator 145 may be arranged in a space surrounded by the side wall 140b and the ceiling wall 140c. Note that the lower end of the side wall 140b should be provided with a sufficient gap between it and the bottom floor LB of the low water channel LR to allow water discharged from the falling channel 140 to flow downstream. Bye. For example, the lower end of the side wall 140b may be provided so as to be located slightly below the water surface when water is flowing at a normal water level in the low water channel LR.

Furthermore, when a plurality of falling channels 140 and generators 145 are provided, each falling channel 140 and generator 145 may be provided with an enclosure having a side wall 140b and a ceiling wall 140c, or all falling channels An enclosure may be provided having side walls 140b and ceiling walls 140c that house channels 140 and generators 145, and several drop channels 140 and generators 145 (e.g., two drop channels 140 and generators 145). 145) may be provided, each having a side wall 140b and a ceiling wall 140c.

The river improvement method of the present invention is suitable as a river improvement method that has a low water channel, a high water bed, and an embankment.

1 Seawall structure 2 Seawall 3 Weir structure 10 Seawall box 11 Main body 11a Opening 11h Space 12 Cover member 20 Weir box 21 Main body 21a Opening 21h Space 22 Cover member 30 Dredging device 31 Floating body 31h Opening 32 Dredging equipment 33 dredging Container 33a Opening 33b Ceiling wall 33h Through hole 33c Side wall 34 Lifting device 35 Suction device 36 Piping 37 Pipe 40 Dredging equipment 41 Container 100 River structure 101 Main structure 101h Space 102 Base structure 105 Storage tank 105b Inner bottom surface 110 Equipment structure 111 Water tank 112 Equipment installation space 113 Drain tank 115 Purification equipment 116 Solar power generation equipment 130 Supply section 135 Water pump 140 Falling channel 145 Generator R River LR Low channel LB Bottom floor LB
HR High water bed B Embankment SD Nakasu SB Installation bottom W Water

Claims (12)

A structure installed between a river and an embankment,
a base structure having a floor surface at a predetermined critical liquid level height;
an equipment structure provided at a distance above the base structure and having a hollow space inside;
a storage tank for storing river water, which is provided on the bottom of a low river channel upstream from the base structure;
a supply unit that supplies water in the storage tank to the hollow space of the equipment structure;
a falling channel provided on the downstream side of the equipment structure and causing water in the hollow space of the equipment structure to fall into a river;
A generator provided in the falling flow path,
The storage tank is
A river structure characterized by having an inner bottom located below the bottom of a low water channel of a river. The hollow space of the equipment structure is
a water tank in which water supplied from the supply section is stored;
a drainage tank in which water to be drained into the falling channel is stored;
The river structure according to claim 1, further comprising a water purification facility provided between the water receiving tank and the drainage tank. 3. The river structure according to claim 1, wherein a channel space for flowing river water is provided between the base structure and the equipment structure. The equipment structure includes:
A ceiling member is installed to cover the hollow space,
3. The river structure according to claim 1, wherein the ceiling member is provided with a solar power generation panel. On the upstream side of the base structure,
A plurality of revetment boxes are installed in parallel along the flow direction of the river on a flat installation bottom formed along the flow direction of the river by excavating the boundary between the low water channel and the high water bed in the river. It is equipped with a pair of revetment structures,
Each seawall box is
3. The river structure according to claim 1 or 2, wherein the hollow box-like body is filled with dredged earth and sand from the bottom of a low water channel and a sandbar. A plurality of revetment boxes are installed in parallel along the flow direction of the river on a flat installation bottom formed along the flow direction of the river by excavating the boundary between the low water channel and the high water bed in the river. Equipped with a pair of seawall structures formed,
Each seawall box is
A river structure characterized in that a hollow box-shaped body is filled with dredged earth and sand from the bottom of a low-lying waterway and sandbars. It is equipped with a weir structure installed to connect the pair of revetment structures,
The weir structure is
7. The river structure according to claim 6, wherein the river structure is formed by connecting a plurality of the bank protection boxes. The weir structure is
It has a waterway that passes water from upstream to downstream,
8. The river structure according to claim 7, wherein a hydroelectric power generation device is installed in the waterway.
In rivers, the boundary between low water channels and high water beds is excavated to form a flat installation bottom along the direction of river flow.
A plurality of hollow revetment boxes having an opening at the top end are installed side by side along the direction of river flow on the formed installation bottom,
Dredge the bottom floor of low water channels and/or sand from sandbars, and put the dredged sand into multiple seawall boxes.
A method for improving a river, comprising: sealing the openings of the plurality of revetment boxes when a predetermined amount of earth and sand is stored in the plurality of revetment boxes to form a pair of revetment structures. A floating body equipped with dredging equipment is floated on river water,
The method according to claim 9, characterized in that the floating body is moved along the flowing direction of the river while dredging the bottom floor of the low water channel and/or sand on the sandbar, and the dredged earth and sand is put into a plurality of bank protection boxes. How to improve rivers. The dredging equipment is
a hollow box-like dredging container that ascends and descends through an opening provided in the floating body;
a lifting device that lifts and lowers the dredging container;
A suction device that sucks up the earth and sand in the dredging container,
The dredging vessel is
It is a hollow box-shaped body whose upper end is closed by a ceiling wall and an opening is formed at the lower end.
The lifting device is
It has a function of pressing the lower end of the dredging container against the bottom floor of a low waterway and/or the earth and sand of a sandbar so that the earth and sand enter the dredging container,
11. The river improvement method according to claim 10, further comprising supplying the earth and sand sucked up from inside the dredging container by the suction device to a plurality of revetment boxes. A plurality of hollow revetment boxes are installed side by side so as to cross between the pair of revetment structures,
Dredge the bottom floor of low water channels and/or sand from sandbars, and put the dredged sand into multiple seawall boxes.
10. The river improvement method according to claim 9, further comprising the step of sealing the openings of the plurality of revetment boxes to form a weir structure when a predetermined amount of earth and sand is accommodated in the plurality of revetment boxes.

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