JP2003119758A - Constriction method and device for removing sediment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method and a device for removing sediment on a bottom of a dam lake, which allows the sediment to be efficiently removed from the dam and can greatly reduce the cost of removal of the sediment. SOLUTION: Bifurcated piping (3) is arranged in the dam lake (2); an end (3ae) of one branch pipe (3a) is arranged in the vicinity (including the inside of a layer of the sediment 2a) of a bottom part (2c) of the dam lake (2); an end (3be) of the other branch pipe (3b) is arranged above the sediment (2a); piping (3c), into which the two branch pipes (3a and 3b) are merged, goes over the dam (1) (for example, straddles a top part 1a of the dam 1 or is arranged through a through-hole 1b provided in the dam 1), so as to be extended to a downstream side (1c); the sediment (2a) is sucked in from the end (3ae); water (2b) is sucked in from the branch pipe (3b); and a solid-liquid two-phase flow (2ab), which is composed of the sediment (2a) and the water (2b), flows through the piping (3c).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for solving the problem of dam sedimentation.

[0002]

2. Description of the Related Art As a conventional method for removing sediment deposited on the bottom of a dam lake, the reality is that a dredging boat is floated on the dam lake and the sediment is dredged. However, the amount of sediment deposited on the bottom of the dam lake is much larger than the dredging capacity of the dredger, and it is not an effective solution with the dredger.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above-mentioned prior art, and it is possible to efficiently remove the sediment of the dam, and to keep the sediment removal cost extremely low. The purpose is to provide a construction method and equipment for removing sediment from the bottom of the dam lake.

[0004]

According to the sediment removal method of the present invention, a forked pipe (3) is arranged in a dam lake (2) and an end (3ae) of one branch pipe (3a) is arranged. ) Is arranged near the dam bottom (2c) (including the layer of the sediment 2a),
The end (3be) of the other branch pipe (3b) is deposited with sand (2a)
The pipe (3c), which is arranged above the dam (1), merges the two branch pipes (3a, 3b) beyond the dam (1) (dam top 1
(including the case of straddling a and the case of being arranged in the through-hole 1b provided in the dam 1) extending to the downstream side (1c), and depositing sand from the end (3ae) of the one branch pipe (3a) (2
a) is sucked in, and water (2
b) is sucked, and a solid-liquid two-phase flow (2ab) of sediment (2a) and water (2b) is configured to flow in the combined pipe (3c) (claim 1 : Fig. 1).

In the sediment removing apparatus of the present invention, a pipe (3) branched into two branches is arranged in the dam lake (2), and one branch pipe (3a) is provided with sediment (sand, mud, etc.). Sediment (2)
The end part (3ae) is arranged in the vicinity of the dam lake bottom part (2c) (including the layer of the sediment 2a) so as to suck in a), and the other branch pipe (3b) stores the water (2b). The end portion (3be) is arranged above the sediment (2a) so as to be sucked, and the pipe (3c) where the two branch pipes (3a, 3b) join together passes over the dam (1) ( It is characterized in that it extends to the downstream side (1c) (including the case of straddling the dam top 1a and the case of being arranged in the through hole 1b provided in the dam 1) (claim 5: FIG. 1).

According to the present invention having such a structure, the sediment (2a) and the water (2) flowing in the merged pipe (3c) are used.
The solid-liquid two-phase flow (2ab) with b) crosses the dam (1) and flows to the downstream side (1c) of the dam by the siphon principle. Here, since the solid-liquid two-phase flow (2ab) of sediment (2a) and water (2b) is sucked from the dam lake bottom (2c) according to the siphon principle, it is different from the case of using the conventional dredger. Differently, as long as there is a height difference (level difference) between the dam lake surface (2d) and the downstream (1c) river, suction and removal work of the sediment (2a) is continuously performed.

Here, the other branch pipe (pipe 3b:
Diameter "Db" of the branch pipe for sucking water, and the diameter of the pipe (pipe 3c) where the other branch pipe (3b) and the one branch pipe (pipe 3a: the branch pipe for sucking sediment) merge "D
The “c” is preferably Dc> Db (FIG. 1,
(Fig. 2). According to this structure, the static pressure at the confluence (3d) of the other branch pipe (pipe 3b) and the one branch pipe (pipe 3a) decreases, and the one branch pipe (pipe 3)
This is because the amount of sediment (2a) sucked in a) increases.

Further, if the diameter dimension of the downstream side (the portion 1c where the level is lowered beyond the dam, beyond the dam) from the confluence point (3d) of the pipes 3 is "De", it is preferable that De>Dc> Db. (FIGS. 1 and 2). This is because with this configuration, the siphon effect is more effectively exhibited.

According to the method for reducing resistance to sediment transport of the present invention, an air inlet pipe (30f) flows into a solid-liquid two-phase flow (2ab) flowing in the sediment transport pipe (30) and containing sediment and water. Solid-gas three-phase flow (2ab
It is characterized in that it is made to be f) (claim 2: FIG. 3, FIG. 4).

In order to carry out such a method for reducing sediment transport resistance, the sediment transport pipe (30) of the present invention is a main pipe (30) through which a solid-liquid two-phase flow (2ab) containing sediment and water flows.
c) and the end portion (30fe) is open to the atmosphere, and the main pipe (3) is configured so that air (F) flows inside thereof.
0c), and an air inflow pipe (30f) communicating therewith (claim 6: FIG. 3, FIG. 4).

According to the method for reducing sediment transport resistance and the pipe for transporting sediment according to the present invention having the above-mentioned structure, the pipe for air inflow (30) into the solid-liquid two-phase flow (2ab) containing sediment and water.
By mixing air (F) via f)
By making the phase flow (2abf), the frictional resistance between the solid phase sand / mud and the pipe wall can be reduced, and the pressure loss can be reduced.

In the sediment transport method of the present invention, a sediment transport pipe (3) is installed in a river (R) downstream of a dam, and the sediment is transported by the dynamic pressure of the stream (TR) of the river (R). Solid-liquid two-phase flow (sediment flow T
It is characterized in that a head is added to S) (claim 3: FIG. 5 to FIG. 9).

The sediment conveying apparatus of the present invention for carrying out such a sediment conveying method is installed in a river downstream of a dam, and a solid-liquid two-phase flow (sediment flow TS) containing sediment and water flows through it. It has a sediment transport pipe (3), and the sediment transport pipe (3) is equipped with a pressure sensor valve (V) for detecting and opening and closing the dynamic pressure of the river flow (TR), The sensor valve (V) is opened when the dynamic pressure of the river flow (TR) becomes higher than a predetermined value with respect to the dynamic pressure of the solid-liquid two-phase flow (sand flow TS), and the flow of the river ( (TR) head is added to the solid-liquid two-phase flow (earth and sand flow TS) (claim 7: FIG. 5).

Alternatively, the sediment transporting apparatus of the present invention is installed in the river (R) downstream of the dam (1) to generate a solid-liquid two-phase flow (sediment flow TS, TS1, TS2) containing sediment and water. It has a sediment transport pipe (3) which flows through, and the sediment transport pipe (3) is provided with a rotating body (first water wheel 71 and second water wheel 72) therein, The body (71, 72) is
The head is added to the solid-liquid two-phase flow (sediment flow TS) containing sediment and water by rotating by the flow (TR) of the river (claim 8: FIG. 6).

Here, the rotating bodies 71 and 72 are the first rotating body (turbine 71) which is rotated by the flow (TR) of the river.
And solid-liquid two-phase flow including sediment and water (debris flow TS1)
A second rotating body (turbine 72) for adding a head to the
Rotation of the rotating body (turbine 71) of the second rotating body (turbine 7
It is preferable to have a rotation transmission mechanism (for example, the engagement between the blades w1 and w2 of the first and second water turbines) that transmits to 2).

Further, the sediment transporting apparatus of the present invention is for transporting sediment which is installed in a river (R) downstream of a dam and through which a solid-liquid two-phase flow (sediment flow TS) containing sediment and water flows through. Plumbing (3)
And a rotating body (turbine 7) that rotates by the flow of the river (TR), and the sediment transport pipe (3) is provided with screw-shaped transport means (4, 4a, 4b) therein. A rotation transmission mechanism (turbine 7) that transmits the rotation of the rotating body (turbine 7) to the screw-shaped conveying means (4, 4a, 4b).
Shaft 7s, an end gear 7g, and an end gear 5) of the screw type conveying means 4) (claim 9: FIGS. 7 to 9).

According to the sediment transporting method and the sediment transporting apparatus of the present invention having such a configuration, the solid-liquid two-phase flow (sediment flow TS) containing the sediment and water by using the flow of the river (R). Since the head is added to the head or the sediment (earth and sand) is conveyed, a separate power source is not required for the head load or conveyance. In other words, by utilizing the energy of the flow (TR) of the river (R) that is semi-permanently supplied, the bottom of the dam lake (2c)
It is possible to effectively transport the sediment that has been suctioned and removed from the soil.

In addition to this, in the method for preventing sediment retention according to the present invention, a sediment conveying pipe (3) is installed in a river downstream of the dam, and the sediment conveying pipe (P) is a part thereof. (P1) is configured to be rotatable, and the rotatable portion (P1) of the sediment transport pipe (P) due to the dynamic pressure of the river flow (TR).
Is rotated (claim 4: FIG.
0).

The sediment accumulation prevention device of the present invention for carrying out such sediment accumulation prevention construction method uses a sediment conveying pipe (P) installed in the river downstream of the dam and a river flow (TR). And a rotating rotating body (turbine 17), and a part (P1) of the sediment conveying pipe (P) is configured to be rotatable. It has a rotation transmission mechanism (shaft 17s of the water wheel 17, end gear 17g, end gear Pg of rotatable portion P1) that transmits to the rotatable portion (P1) of the sand transport pipe (P). (Claim 1
0: FIG. 10).

According to the sedimentation stagnation prevention method and apparatus of the present invention having the above-mentioned structure, one portion (P1) of the sediment transport pipe (P) is rotated by the flow of the river. As the rotatable part (P1) rotates, the sand accumulated in the part (P1) moves (relatively), and the sediment transport pipe (P)
The sediment flow is carried and carried by the sediment flow.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the first embodiment showing the sedimentation (suction) method and apparatus shown in FIG. 1, a pipe 3 branched into two branches is arranged in a dam lake 2 having a dam 1.

One branch pipe 3a of the pipe 3 has its end 3ae in the vicinity of the dam lake bottom 2c (in the layer of the sediment 2a so that the sediment (sand, mud, other sediments) 2a is sucked in. (Including also)), the other branch pipe 3b, water (water storage) 2b
The end portion 3be thereof is arranged above the sediment 2a so as to suck the sand.

The two branch pipes 3a, 3b of the pipe 3
The pipe portion 3c that joins is inserted so as to penetrate the through hole 1b provided in the dam 1, and the end portion is arranged so as to extend to the downstream side 1c of the dam 1. Incidentally, the two branch pipes 3a, 3
The pipe portion 3c where b and the two branch pipes 3a and 3b join each other is configured such that the diameters of the respective pipes are substantially the same.

According to the embodiment of the sediment removing method and apparatus having such a configuration, the sediment (sand / mud) 2a can be sucked and removed from the dam lake bottom 2c by the siphon principle. Therefore, the natural sand, that is, the potential energy of the stored water of the dam lake 2, can be used to remove the sediment 2a on the lake bottom 2c of the dam lake without administering fuel or other energy.

In FIG. 2 showing the essential part of the second embodiment of the sediment removing device, in the first embodiment of FIG. 1, the diameter Db of the other branch pipe 3b which mainly sucks water and sand and mud are removed. The diameter Da of the one branch pipe 3a to be sucked and the diameter Dc of the merging pipe portion 3c where the other branch pipe 3b and the one branch pipe 3a are merged were substantially equal, whereas the second embodiment of FIG. Then
The diameter Db of the other branch pipe 3b, the diameter Dc near the confluence point on the downstream side of the confluence point of the confluence pipe portion 3c, and the level lower than the lake surface 2d at a position beyond the dam on the downstream side of the confluence pipe portion 3c. In the diameter De at different positions, the size of each diameter is different. That is,
It is preferable that the relationship of the diameters of the respective tube portions be De>Dc> Db.

According to the embodiment of the sediment removing method and apparatus having such a configuration, the principle of siphon can be more effectively performed.

FIGS. 3 and 4 show one embodiment of the method for reducing sediment transport resistance and piping used in the present invention, in which the earth and sand sucked by the sediment removing apparatus of FIGS. It is a pipe for carrying.

In FIG. 3, the sediment conveying pipe 30 includes a solid-liquid two-phase flow-through portion 30ab and a solid-liquid two-phase flow-through portion 30a.
The solid-gas three-phase flow passage portion 30abf continuous with b. An air inflow pipe 30f provided with an air inlet 30fe is provided in the vicinity of a position of the solid-liquid 3-phase flow-through portion 30abf which is continuous with the solid-liquid 2-phase flow-through portion 30ab. It is provided so as to join the flow-through portion 30abf at a right angle.

The diameter of the solid-liquid two-phase flow-through portion 30ab is D
0, and assuming that the diameter of the solid-gas-liquid three-phase flow-through portion 30abf is D1, there is a relationship of D0 <D1.

Further, FIG. 4 shows an air inflow pipe 30 in FIG.
The only difference is that f was orthogonal to the solid-gas-liquid three-phase flow-through portion 30abf and was provided obliquely rearward.
In FIG. 4, symbols R, TR, and TS are rivers, river streams, and
The sediment flow is shown.

According to the embodiment of the method for reducing sediment-conveying resistance and the pipe having the above-mentioned structure, the control pressure at the confluence point 30d in FIG. 3 becomes lower than the air pressure (atmospheric pressure).
As a result, the solid-liquid two-phase flow 2ab is changed to the solid-gas three-phase flow 2abf. Further, the inflow of the air F can reduce the frictional resistance between the solid phase sand / mud and the pipe wall 30g, reduce the pressure loss, and enable smooth removal of the sediment.

5 to 9 show a method and apparatus for transporting sediment according to the present invention, which utilizes the flow of a river as a power source to transport the sediment sucked and removed from the bottom of the dam lake.

FIG. 5 showing the first embodiment of the sediment transporting method and apparatus of the present invention is that the dynamic pressure due to the flow TR of the river is higher than the dynamic pressure of the flow TS containing sediment by a predetermined value or more. If so, the pressure sensor valve (normally closed: the closed state is shown by the solid line and the open state is shown by the dotted line) V provided in the sediment transport pipe 32 is opened (the state shown by the broken line), and the river flow TR is reached. Head (dynamic pressure) is added to the sediment flow TS, and the head of the sediment flow TS is increased by the added head, and as a result, sediment (sediment)
Is a method of transporting.

In FIG. 5, the sediment transport pipe 3 has an outer pipe 3o through which the inlet end 3n side allows the river flow TR to flow through in a certain section.
And an inner pipe 3i that allows the sediment flow TS to flow through, and the inner pipe 3i is terminated after passing the certain section, and the outer pipe 3o has a diameter substantially equal to that of the inner pipe. The size is reduced to the same extent, and thereafter, the single pipe 3t having only the outer pipe is changed, and the river flow TR and the sediment flow TS are mixed and flow inside.

A pressure sensor valve V that detects the dynamic pressure due to the flow TR of the river at the rear end of the inner view 3i in the vicinity of the contraction portion of the outer pipe 3o and opens when the dynamic pressure exceeds a predetermined value. Is intervening.

In this embodiment, which is equipped with such a method and apparatus for transporting sediment, the energy of the flow TR of the river is utilized as the energy for transporting sediment (sand), and only minute energy consumed for opening and closing the sensor is used. Need. In other words,
Immortal natural energy can be used as a transport energy.

FIG. 6 showing a second embodiment of the method and apparatus for transporting sediment according to the present invention is shown in FIG.
Is rotated, and the rotation of the water turbine 71 is transmitted to the water turbine 72 by the engagement between the blades of the water turbine 71 and the blades of the water turbine 72.
This is a method of adding a head to the sediment flow TS by rotating 2 times.

In FIG. 6, the sediment transport pipe 3 has a water turbine storage portion 3h which is opened at a position apart from the inlet end 3n by a predetermined distance in a direction orthogonal to the axis 3ct of the pipe. The second water turbine 72 and the first water turbine 71 are installed so as to rotate in a plane including the flow TR of the river in order in the direction away from the shaft 3ct.

The first turbine 71 and the second turbine 72 have the same number of blades w1 (on the first turbine 71 side) and w2 (the second turbine 7).
2)), and the blade w2 on the side of the second turbine 72 is a position where a certain blade w2 is vertically upward at a certain point in time, and the front surface w2f of the vertically upward blade w2 at this time is Among the blades w1 on the side of the first water turbine 71, a certain blade w1 is in the vertically downward position at the same time, and the rear surface w1 of the vertically downward blade w1 at this time.
Engages with r with a predetermined lap amount (at a contact position). The front surface mentioned above indicates the downstream side in the river flow TR or the sediment flows TS1 and TS2, and the rear surface indicates the upstream side. Here, TS1 indicates the sediment flow (streamline) before the head is added (increasing the flow velocity) by the water turbine 72, and TS2 indicates the sediment flow (streamline) after the head is added by the water turbine 71. Show.

Although not shown in the drawing, it is also possible to attach a head to the sediment flow TS with only the water turbine 71.
Further, a rotational force transmission mechanism (conventional / known one) may be interposed between the water wheel 71 and the water wheel 72.

In this embodiment, which is equipped with such a sediment transfer method and apparatus, the energy of the flow TR of the river is supplied to the water wheels 71 and 72.
Is used as the transport energy of the sediment (TS) TS, in other words, immortal natural energy can be utilized as the transport energy.

7 to 9 showing the third embodiment of the sediment conveying method and apparatus of the present invention, the water turbine 7 is rotated by the flow TR of the river, and the sediment conveying is carried out via the shaft 7S of the water turbine 7. This is a method of rotating the screw type conveying means 4 provided in the pipe 3 for use.

In FIG. 7, a water turbine 7 having an axis 7s orthogonal to the sediment conveying pipe 3 and rotating in the direction of arrow M by the river flow TR is installed near the sediment conveying pipe 3. The rotation of the water turbine 7 is caused by meshing between a gear 7g provided at the end of the shaft 7s and a gear 5 at the end of the screw type transport means 4 provided in the sediment transport pipe 3 by screw gear transport means 4 ( 4a, 4b).

One example of the screw type conveying means 4 (4
a) is shown in FIG. In FIG. 8, a pipe 3 for conveying sediment
A spiral projection 4a, which is the screw type conveying means 4, is formed on the inner wall of the.

In this case, returning to FIG. 7, the shaft 7 of the water turbine 7 is described.
Desirably, the gear 7g provided at the end of s is a worm gear, and the gear 5 at the rear end of the screw type transport means 4 is a worm (pinion) gear provided on the outer periphery of the sediment transport pipe 3. With this structure, a part of the sediment transport pipe 3 rotates, and thus the rotating spiral projection 4a formed on the inner wall of the pipe 3 causes the sediment flow T to flow.
S is transported toward the tip of the sediment transport pipe 3.

Another example of the screw type conveying means 4 is shown in FIG. In FIG. 9, a screw feeder 4b is installed inside the sediment conveying pipe 3, and the screw feeder 4b is similar to that shown in FIG. 8, for example, in FIG. 7 by a torque transmission device using a worm gear. The rotation of the water wheel 7 shown is transmitted.

The present embodiment provided with such a sediment transporting method and apparatus is a screw type provided on the sediment transporting pipe 3 via the shaft 7s of the turbine 7 by rotating the turbine 7 by the flow TR of the river. Of the spiral protrusion 4a
Alternatively, the sediment flow TS can be conveyed by the rotational pushing force of the screw feeder 4b. In other words, natural energy can be used as a transportation energy.

First Method and Apparatus for Preventing Sediment Accumulation of the Present Invention
FIG. 10 showing the embodiment shows a water turbine 1 using a river flow TR.
By rotating 7 and further transmitting the rotation of the water wheel 17 to the sediment transport pipe P, one portion P1 of the sediment transport pipe P is rotated. As the part P1 of the pipe P rotates, the sand accumulated in the part P1 moves (relatively) with respect to the part P1, and as a result, the sand is carried by the sediment flow flowing in the pipe P. , Is the method of being transported.

In FIG. 10, a water turbine 17 having an axis 17s orthogonal to the sediment conveying pipe P and rotating in the direction of arrow M by the river flow TR is installed in the vicinity of the sediment conveying pipe P. The rotation of the water turbine 17 is transmitted to the portion P1 of the sediment transport pipe P by the engagement of the gear 17g provided at the end of the shaft 17s and the gear Pg provided on the sediment transport pipe P. It is configured.

In the present embodiment, which is equipped with such a method and apparatus for preventing sediment accumulation, the water turbine 7 is rotated by the flow TR of the river, and a part of the sediment conveying pipe P is passed through the shaft 7s of the water turbine 7. The stirring function by rotating P1 can prevent the accumulation of earth and sand.

The illustrated embodiment is merely an example,
It is additionally noted that the description is not intended to limit the technical content of the present invention.

[0052]

The effects of the present invention are listed below. (1) The solid-liquid two-phase flow of sediment and water is sucked from the bottom of the dam lake according to the siphon principle, and the removal work is continuously performed. (2) A solid-liquid two-phase flow containing sediment and water is mixed with air through an air inflow pipe to make a solid-gas three-phase flow. It is possible to reduce the frictional resistance during transportation. (3) Kinetic energy is applied to the solid-liquid two-phase flow containing sediment and water using the flow of the river, or the sediment is transported, so a separate power source is required for loading and transporting the kinetic energy. do not do. (4) By rotating one part of the sediment transport pipe by the flow of the river, the sand accumulated in the part moves (relatively), and the sediment flow flows through the sediment transport pipe. Since it is carried and transported, it is possible to prevent the accumulation of sediment in the sediment transport pipe.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a sediment removing device of the present invention.

FIG. 2 is a sectional view of an essential part of a second embodiment of the sediment removing device of the present invention.

FIG. 3 is a cross-sectional view showing an example of a sediment carrying resistance reducing device used in the present invention.

FIG. 4 is a cross-sectional view showing another example of the sediment conveying resistance reducing device used in the present invention.

FIG. 5 is a cross-sectional view of essential parts showing a first embodiment of a sediment transporting device of the present invention.

FIG. 6 is a schematic diagram showing a configuration of a second embodiment of a sediment conveying device of the present invention.

FIG. 7 is a three-dimensional view showing the configuration of a third embodiment of the sediment conveying device of the present invention.

8 is a partial detailed view showing an example of the partial details of FIG. 7. FIG.

9 is a partial detailed view showing another example of the partial details of FIG. 7. FIG.

FIG. 10 is a three-dimensional view showing a configuration of an embodiment of a sediment retention device according to the present invention.

[Simple explanation of symbols]

1 ... dam 2 ... Dam Lake 3 ... Piping 2a ... sedimentation 2b ... water 2c ... Dam lake bottom 3a ... One branch pipe 3b ... the other branch pipe 3c: Combined piping 2ab: solid-liquid two-phase flow

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Yoshida             Chemika, 1-6-4 Moto-Akasaka, Minato-ku, Tokyo             Inside Le Grout Co., Ltd. (72) Inventor Masahiro Ichi             Chemika, 1-6-4 Moto-Akasaka, Minato-ku, Tokyo             Inside Le Grout Co., Ltd.

Claims (10)

[Claims] 1. A bifurcated pipe is arranged in a dam lake, one branch pipe end is arranged near the dam lake bottom, and the other branch pipe end is arranged above the sediment. Then, the pipe where the two branch pipes join together is extended to the downstream side beyond the dam, and the sediment is sucked from the end of the one branch pipe, and the water is sucked from the other branch pipe. A method for removing sediments, characterized in that a solid-liquid two-phase flow of water and water is configured to flow in the combined pipe. 2. A solid-liquid three-phase flow is obtained by mixing air into the solid-liquid two-phase flow that flows in the sediment transport pipe and contains sediment and water through the air inflow pipe. A method for reducing the resistance to sediment transport. 3. A sediment conveying pipe is installed in a river downstream of the dam, and a head is provided for a solid-liquid two-phase flow containing sediment and water in the sediment conveying pipe due to the dynamic pressure of the river flow. A method for transporting sediment that is characterized by being added. 4. A sediment conveying pipe is installed in a river downstream of the dam, and the sediment conveying pipe is configured so that a part of the pipe can be rotated. The sediment conveying pipe is constituted by a dynamic pressure of the river flow. A method for preventing sediment retention, which is characterized by rotating the rotatable part of the piping for use. 5. A bifurcated pipe is arranged in the dam lake, one branch pipe has its end arranged near the bottom of the dam lake so as to suck sediment, and the other branch pipe holds water. A sediment removing device characterized in that its end is arranged above the sediment so as to be sucked in, and a pipe in which two branch pipes merge is extended to the downstream side beyond the dam. 6. The sediment conveying pipe used in the sediment conveying resistance reducing method according to claim 2, wherein a main pipe through which a solid-liquid two-phase flow containing sediment and water flows and an end thereof is open to the atmosphere. And a pipe for air inflow that is configured to allow air to flow therein and communicates with the subject subjectively, and a pipe for transporting sediment. 7. The sediment conveying device for carrying out the sediment conveying construction method according to claim 3, wherein the sediment conveying apparatus is installed in a river downstream of the dam and through which a solid-liquid two-phase flow containing sediment and water flows through. And a pressure sensor valve that opens and closes by detecting the dynamic pressure of the river flow. The pressure sensor valve has a two-phase solid-liquid dynamic pressure of the river flow. A sediment transporting device, which is configured to be opened when a pressure higher than a predetermined value with respect to the dynamic pressure of the stream is opened and the head of the stream of the river is added to the solid-liquid two-phase flow. 8. The sediment conveying device for implementing the sediment conveying method according to claim 3, wherein the sediment conveying device is installed in a river downstream of the dam and through which a solid-liquid two-phase flow containing sediment and water flows through. The pipe for transporting sediment is provided with a rotating body inside, and the rotating body is rotated by the flow of a river to head into a solid-liquid two-phase flow containing sediment and water. A sediment transporting device characterized in that it is configured to add. 9. A sediment conveying device for carrying out the sediment conveying method according to claim 3, wherein the sediment conveying is installed in a river downstream of the dam and through which a solid-liquid two-phase flow containing sediment and water flows through. And a rotary body that rotates according to the flow of the river. The sediment transport pipe includes a screw-shaped transport means therein, and transmits the rotation of the rotary body to the screw-shaped transport means. A sediment conveying device having a rotation transmission mechanism. 10. The sediment retention device for implementing the sediment accumulation prevention method according to claim 4, wherein the sediment transport pipe installed in the river downstream of the dam and the rotating body rotating by the flow of the river. And a part of the sediment transport pipe is configured to be rotatable, and has a rotation transmission mechanism that transmits the rotation of the rotating body to a rotatable portion of the sediment transport pipe. A sediment retention device that is characterized by