JP3312427B2 - River sand removal method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing sand deposited on a river.

[0002]

2. Description of the Related Art In a river, sand gradually accumulates due to the erosion and transport of water, and sand bars are formed. Such sedimentary sand reduces the flow area of the river and causes flooding. There is a problem that causes a disaster.

Recently, as a method for removing such sedimentary sand, as shown in FIG. 6, an undulating bag 3 that expands and contracts by a fluid is installed inside a river 1, and sand is accumulated around the undulating bag 3. A method to make it happen is considered. In this method, when the sand is deposited, as shown in FIG.
Is laid down below the surface of the water to form a waterway 16, and the waterway 16
The sand that has accumulated is washed away by the water flowing into the river, and the sand can be removed by natural force, so that there is an advantage that efficient sand removal work can be performed.

[0004]

By the way, in the above-mentioned method, when the sand bag 3 is simply shrunk at the time of sand removal to fall down at once, the amount of water flowing into the water channel 16 and the flow velocity do not become sufficiently large. In some cases, a large flushing force cannot be obtained.

That is, the amount and flow velocity of water flowing into the water channel 16 are determined by the water volume of the river 1, the area of the water channel 16, and the like. When the area of the water channel 16 is rapidly expanded,
The flow velocity of the water flowing in the water channel 16 is significantly reduced,
In some cases, it may not be possible to obtain sufficient water power to flush out the sand. Conversely, if the amount of shrinkage of the undulation bag 3 is reduced and the area of the formed water channel 16 is reduced, the flow velocity of the water flowing through the water channel 16 increases, but on the other hand, the amount of water decreases. There is a problem that large kinetic energy cannot be obtained.

[0006] The deposited sand has a difference in specific gravity due to the difference in components, and the speed of the flushed water can also be different. However, in order to stably remove such deposited sand having a specific gravity difference. It is necessary to appropriately change the amount and flow velocity of water in the water channel according to the specific gravity difference.

In view of the above, according to the present invention, it is possible to pour water having a sufficient flow rate and flow velocity capable of efficiently and quickly discharging sand into a water channel formed by the undulation of the undulating bag, and always exert a large sand discharging power. It is intended to provide a method of removing sand that can be performed.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention installs an undulating bag that expands and contracts by a fluid in a river, and deposits sand around the undulated bag. After that, the undulating bag is laid down below the surface of the water to form a waterway, and in a method for discharging sand deposited by the water of the river flowing into the waterway,
Detection results of river water level, sedimentation sand depth and internal pressure of undulating bags
Thus, a method of controlling the amount of expansion or contraction of the undulation bag based on the above is used to make the undulation bag fall.

[0009]

In the above method, the area of the channel is changed by changing the amount of expansion and contraction of the undulation bag in accordance with the amount of water and the flow velocity in the river at the time of discharge, so that the channel is formed so that sand is quickly washed away. Control the amount of water flowing and the flow velocity.

[0010] Further, when the discharge condition changes due to the difference in the composition of the deposited sand, the area of the water channel is changed by expansion and contraction of the undulation bag in accordance with the change, so that the sufficient sand discharge force by the water is obtained. The flow rate of water and the like are controlled so that is obtained.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3, reference numeral 1 denotes a river,
At the outlet of the river 1, a plurality of undulating bags 3 are installed at predetermined intervals from the riverbank 2, respectively.

Each of the undulating bags 3 is formed in a shape that is long in one direction, and is provided so that the longitudinal direction thereof substantially follows the flow of water in the river 1 (the direction indicated by the arrow in the figure). The distance a between the undulation bags 3 and the distance b between the undulation bags 3 and the riverbank 2 are set such that sand carried along with the water while the water of the river flows gradually settles around the undulation bags 3, and The size is set so that sand is deposited.

As shown in FIG. 4, the undulating bag 3 is formed by forming a concrete ground 4 on the river bottom, and fixing a rubber-made cloth 5 formed in a cylindrical shape on the ground 4 with anchor bolts 6. Mounted.

The rubber cloth 5 forming the undulating bag 3 is formed by laminating several layers of nylon cloth on chloroprene rubber or synthetic rubber having weather resistance and wear resistance equal to or higher than that of chloroprene rubber. By introducing a fluid such as air or water into the inside, the rubberized cloth 5 expands and the bag rises. Conversely, when the fluid is removed from the inside of the rubberized cloth 5, the bag contracts and falls down. In this case, the up-and-down bag 3 stands upright, and its upper end slightly protrudes from the water surface of the river as shown in FIG.
Conversely, in the laid-down state, as shown in FIG. 9, the entire undulation bag sinks below the water surface, and is brought into a state of being pressed on the ground 4 by water pressure.

As shown in FIGS. 2 to 4, a supply / discharge port 7 for a fluid such as air or water is formed at the bottom of the undulating bag 3, and the supply / discharge port 7 is provided with an operation room installed on the ground. A supply / exhaust pipe 8 is connected to the supply pipe 9. An upstream water level detection pipe 10 and an internal pressure detection pipe 11 are provided between the operation room 9 and the undulation bag 3, and a sand depth detector for detecting the depth of the deposited sand is provided between the undulation bag 3. 12 are provided.

The operation room 9 is provided with a blower 13 (or a pump) for supplying a fluid to the undulating bag 3, and a control device 14 for controlling the supply and discharge of the fluid, the supply amount and the discharge amount. I have. As shown in FIG. 5, detection signals from the upstream water level detection pipe 10, the internal pressure detection pipe 11, and the sand depth detector 12 are input to the control device 14, while the blower 13 is supplied from the control device 14. A control signal is output to the drive circuit 15 of the first embodiment. The control device 1
The operation of 4 is manually performed by an operator based on the detection results of various detection tubes, or automatically performed based on a preset program. The setting is such that the switching of the supply and discharge of the fluid, the supply amount and the discharge amount change, and the expansion amount and contraction amount of each undulation bag 3 are controlled.

This embodiment has the above-mentioned structure, and its operation will be described below. When depositing sand, as shown in FIGS. 2 and 3, a fluid is introduced into each undulation bag 3 to expand it, and each undulation bag 3 is kept upright inside the river 1. As a result, as shown in FIG. 6, the sand carried along with the water of the river 1 flows between the undulation bags 3 and between the undulation bags 3 and the riverbanks 2.
It gradually accumulates in between to form sand bars.

[0018] sand around each undulation bag 3 is deposited, release the fluid to contract the bag from the inside of the undulations bag 3, it is laid down on the water surface downward as shown in FIG. As a result, a water channel 16 is formed in the portion of the undulating sack, and the water of the river 1 flows into the water channel 16 in a concentrated manner, so that the flowing water pushes the sedimentary sand around the water channel 16 toward the sea.

At the time of discharging the sand, if the amount of water in the river is relatively small, the fluid is gradually discharged from the undulating bag 3 and the contraction amount of the undulating bag 3 is changed stepwise as shown in FIGS. Let it. As a result, the area of the water channel 16 gradually increases, so that high-speed water can always flow through the water channel 16,
Sand can be washed away at a high speed. In addition, waterway 16
When the flow rate of the water decreases due to excessive opening, the fluid is supplied to the up / down bag 3 to expand the bag again, and the area of the water channel 16 is reduced to increase the flow speed.

On the other hand, when the specific gravity of the deposited sand is large and it is desired to obtain a larger sand discharging force, the fluid is rapidly discharged from the undulating bag 3 to reduce the area of the water channel 16 to the state shown in FIG. Expand rapidly. This allows a large amount of water to flow
6 at a time, and even heavy sand can be efficiently discharged.

Further, when there is a variation in the amount of sand discharged due to a difference in the type of the constituents of the deposited sand and specific gravity, etc.,
The expansion and contraction states of the undulation bag 3 are alternately changed according to the sand discharge state, and the area of the water channel 16 is controlled so as to obtain an optimal water amount and flow velocity according to the type of sand and the like.

When the sand is discharged in this way, the fluid is again introduced into each of the up-and-down bags 3 to be erected, and the above-described operation from the accumulation of the sand to the discharge thereof is repeated.

The number of the undulation bags 3 installed inside the river is not particularly limited, and can be appropriately set according to the size of the river. Further, if a small river or a small amount of sand is deposited, at least one undulating bag may be provided in the river.

[0024]

As described above, according to the sand discharging method of the present invention, when the undulating bag is laid down, the expansion or contraction state of the undulating bag is changed to control the flow rate and flow velocity of the water flowing into the water channel. Depending on the amount of water in the river and the type of sand components that have been deposited, the optimal flow rate and amount of water for quickly flushing the sand can be set, which has the effect of stably and efficiently discharging sand. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an entire sand discharging device according to an embodiment.

FIG. 2 is a longitudinal sectional view of the undulating bag according to the first embodiment, taken along a longitudinal direction.

FIG. 3 is a cross-sectional view of the undulating bag.

FIG. 4 is a cutaway perspective view showing the internal structure of the undulating bag.

FIG. 5 is a block diagram showing a control structure of the above.

FIG. 6 is a plan view showing the accumulation state of the above sand.

FIG. 7 is a plan view showing a sand discharging state of the above.

FIG. 8 is a cross-sectional view showing a sand discharging state of the above.

FIG. 9 is a cross-sectional view showing a sand discharging state of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 River 3 Undulating bag 8 Supply / exhaust pipe 13 Blower 14 Control device 16 Waterway

────────────────────────────────────────────────── (5) References JP-A-7-18640 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02B 3/02 E02B 7/20 106

Claims (1)

(57) [Claims] 1. An undulating bag that expands and contracts with a fluid is installed inside a river, and sand is deposited around the erected sack, and the undulating bag is laid down below the water surface to form a water channel. and, in sediment method rivers sweep away the sand deposited by the water of a river flowing into the water channel, at the discharge of the sand, river
For detecting the water level of river, the depth of sedimentation sand and the internal pressure of undulating bags
A method for discharging sand from a river, comprising controlling the amount of expansion or contraction of the undulating bag based on the undulating bag.