JP2006241790A - System and method for transporting dredged sediment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently discharge a large amount of sediment, accumulated on the bottom of water in a large-capacity reservoir such as a dam, to the sea or a river near the sea, with relatively little energy at a relatively low cost, in consideration for preventing an influence on the natural environment to the utmost. <P>SOLUTION: This system comprises: a siphon pipe S for sucking out dredged sediment 1 in the large-capacity reservoir D such as the dam along with water by utilizing a siphon action; and a gravity flow path P which communicates with the downstream end of the siphon pipe S, and which makes the dredged sediment 1, sucked out by the siphon pipe S, and a fluid, including the water, gravitationally flow down to the sea O or the river R near the sea O by utilizing gravitation. The path P comprises a plurality of pipelines Pp which are mutually arranged in a column, and a relay pit Pm which is interposed between the pipelines Pp adjacent to each other and where the fluid flowing down from the upstream-side pipeline Pp can be temporarily stored and discharged to the downstream-side pipeline Pp. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a dredged sand transport system for transporting dredged sand from a large-capacity reservoir such as a dam where river water flows in a high place away from the sea from the reservoir to the sea or a nearby river, The present invention also relates to a method for transporting dredged sand using the transport system.

  In addition, in this specification, "soil and sand" includes earth and sand, mud, sludge, etc., or a mixture thereof generated when dripping the bottom of a large-capacity reservoir such as a dam. In the present invention, the term “large capacity reservoir” includes various dams (for example, lakes, recreational ponds, etc.) in which a decrease in effective depth due to sediment accumulation from the upstream side of the river is a problem. Regardless of whether it is an artifact or a natural object.

  As an important current issue for existing dams used for hydropower generation and irrigation, a large amount of sediment flowing from the upstream side accumulates on the bottom of the dam for many years, reducing its effective depth. As a result, the power generation capacity of the dam is reduced or the amount of stored water is reduced.

Therefore, in order to deal with such problems, for example, it has already been attempted to remove the sediment from the bottom of the dam and carry it out of the dam. A technique for sucking and transporting to a collection place around the dam has already been proposed (see Patent Document 1 below).
JP 11-46515 A

  However, it takes a lot of labor and energy (and therefore costs) to carry a large amount of dredged sand out of the vicinity of a dam that is often installed in the mountains and road conditions are not so good. In particular, this problem becomes prominent when dumping dam sedimentary sediment to the sea where it should flow (if there is no dam), and also causes traffic congestion.

  In order to transport the dam sediment to the sea while avoiding such problems, for example, it may be possible to release the dredged sediment directly to the river immediately downstream of the dam. It may cause water pollution and affect the river ecosystem.

  The present invention has been proposed in view of the above circumstances, and a large amount of earth and sand deposited on the bottom of a large-capacity reservoir such as a dam has a relatively low energy and cost and does not affect the natural environment as much as possible. It is an object of the present invention to provide a new dredged sand transport system and a transport method thereof that can efficiently discharge to the sea or a river near the sea.

  In order to achieve the above object, the invention of claim 1 transports dredged sand of a large-capacity reservoir in a high place away from the sea into which river water flows from the reservoir to the sea or a river near it. A dredged sand transport system that siphons out dredged sand from a large-capacity reservoir together with water by a siphon, and a fluid containing dredged sand and water that is connected to the downstream end of the siphon pipe and sucked out by the pipe. At least a natural flow path that naturally flows down to the sea or a nearby river using gravity, and the natural flow path is between a plurality of pipelines arranged in tandem with each other and adjacent pipelines. And a relay rod that can temporarily store the fluid flowing down from the upstream pipeline and discharge it to the downstream pipeline.

  In addition to the above feature of claim 1, the invention of claim 2 is capable of separating water from the fluid flowing down through the natural flow path and discharging it into the sea or a nearby river, and the remaining The water / sediment separation processing means capable of temporarily storing dredged soil and recovering at least a part of the dredged soil is arranged continuously to the downstream end of the most downstream pipeline of the natural flow path. .

  Further, the invention of claim 3 is characterized in that, in addition to the above feature of claim 2, the water / sediment separation means receives the fluid that has flowed down through the natural flow path and receives dredged soil in the fluid. A plurality of settling tanks are arranged so that the supernatant water in the fluid in each settling tank can be sequentially overflowed to the downstream settling tank, and the supernatant water overflowed from the most downstream settling tank It is characterized by the fact that it was released into the sea or a river near it.

  In addition to the above feature of claim 3, the invention of claim 4 is characterized in that the plurality of sedimentation tanks are open at their upper surfaces, and are sequentially connected in series from the upstream side to the downstream side of the riverbed of the estuary. It is arranged by these.

  In addition to the above features of claims 1 to 4, the invention of claim 5 is characterized in that each relay rod has an inlet portion to which an upstream pipeline is connected and an outlet portion to which a downstream pipeline is connected. And an opening / closing valve is provided at each of the inlet portion and the outlet portion.

  In addition to the above features of claims 1 to 5, the invention of claim 6 includes microbubble supply means for supplying countless fine bubbles into the siphon tube or at least a part of the pipeline. It is characterized by that.

  The invention of claim 7 is a method for transporting dredged sand using the transport system according to any one of claims 1 to 6, wherein at least part of the dredged sediment deposited and deposited in at least one relay dredger. Is collected so that it does not flow into the downstream pipeline.

  Further, the invention of claim 8 is a method for transporting dredged sand using the transport system according to any one of claims 1 to 6, wherein at least a part of the relay pad has another large capacity in the vicinity thereof. A fluid containing water sucked out from a reservoir and dredged soil is supplied.

  As described above, according to the present invention, dredged sand of a large-capacity reservoir located at a high place away from the sea is sucked out together with water by the siphon action of the siphon tube, and then is passed through the natural flow passage or near the sea. Since it was allowed to flow down naturally to the river, dredged sand in the large-capacity reservoir can be transported to the sea or nearby rivers without any difficulty using gravity, saving energy and reducing costs for the transport. In addition, there is no fear of polluting the river water area on the way with dredged soil or affecting the ecosystem, and there is no possibility of causing problems such as traffic congestion as in the case of transportation by dump truck. The natural flow path is interposed between a plurality of pipelines arranged in tandem with each other and adjacent pipelines, and temporarily stores the fluid flowing down from the upstream pipeline. Since it has a relay rod that can be discharged downstream, the internal pressure of each pipeline can be reduced and its durability can be increased, and maintenance on the pipeline can also be performed in units of pipelines separated by relay rods. Therefore, the maintenance work becomes relatively easy.

  Further, in particular, according to the invention of claim 2, the water / sediment separation processing means arranged continuously to the downstream end of the most downstream pipeline of the natural flow path is compared with the fluid flowing down through the natural flow path. Only clean water can be discharged to the sea or nearby rivers, and the remaining dredged sand can be temporarily stored in the water / sand separating means, and at least a part of it can be recovered. Compared with the case where the whole is discharged as it is to the sea or a nearby river, the water pollution of the sea or a nearby river and the influence on the ecosystem can be suppressed as much as possible.

  In particular, according to the invention of claim 3, the water / sediment separation processing means includes a plurality of settling tanks for receiving the fluid flowing down through the natural flow path and precipitating the dredged sand in the fluid. The supernatant water in the fluid in each sedimentation tank is arranged so that it can overflow into the downstream sedimentation tank in sequence, and the supernatant water overflowing from the most downstream sedimentation tank is sent to the sea or a river near it. Since it was made to discharge, the cleanliness of the discharged water can be improved, and the water pollution of the sea or the river near it and the influence on an ecosystem can be suppressed more effectively.

  In particular, according to the invention of claim 4, each of the plurality of sedimentation tanks has an open upper surface, and is disposed in series in the river bed near the mouth from the upstream side to the downstream side. By using a large space in the riverbed near the river mouth, a relatively large settling tank can be arranged in multiple stages, and the water purification function can be enhanced accordingly. In addition, when the riverbed at the estuary is submerged due to flooding, the sediment in each sedimentation tank can be easily washed away by the muddy flow of the river.

  Further, in particular, according to the invention of claim 5, each relay rod includes an inlet portion to which an upstream pipeline is connected and an outlet portion to which a downstream pipeline is connected. Since each of the outlets is provided with an on-off valve, the above-mentioned pipeline maintenance work can be performed more efficiently and accurately by appropriately opening and closing the on-off valves, and the flow rate of the fluid flowing through each pipeline can be adjusted. It is also relatively easy to stop the flow during an emergency.

  Further, particularly according to the invention of claim 6, since the microbubble supply means for supplying countless fine bubbles to the inside of the siphon tube or at least a part of the pipeline is provided, the fluid of countless fine bubbles is provided. In addition to effectively reducing frictional resistance between the fluid and the inner surface of the siphon tube or pipeline, the density of the fluid can be reduced and the fluid can smoothly flow. Is possible. Also, since the aerobic microorganisms in the fluid can be sufficiently brought into contact with oxygen in the microbubbles and the microorganisms can be activated, the odor and turbidity of the fluid reaching the sea or near the estuary And the amount of dissolved oxygen increases, which is advantageous for environmental measures.

  In particular, according to the invention of claim 7, since at least a part of the dredged sediment deposited and accumulated in at least one relay dredger is collected so as not to flow into the downstream pipeline, This is convenient when reclaiming dredged soil as construction material, agricultural material, etc., and can reduce the flow of dredged soil to the sea by that amount.

  In particular, according to the invention of claim 8, at least a part of the relay dredger is supplied with a fluid containing water sucked from other large-capacity reservoirs in the vicinity thereof and dredged soil. The dredged sand from the large-capacity reservoir can be easily merged at the relay dredger, and can be naturally flowed to the sea side using the pipeline on the downstream side.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on examples of the present invention illustrated in the accompanying drawings.

  In the accompanying drawings, FIGS. 1 to 8 show a first embodiment of the present invention. FIG. 1 is an overall schematic longitudinal sectional view showing an outline of a dredged sand transport system, and FIG. Fig. 3 is an enlarged view of the portion indicated by the arrow 3 in Fig. 1, Fig. 4 is an enlarged sectional view taken along line 4-4 of Fig. 3, Fig. 5 is an enlarged view of the portion indicated by arrow 5 in Fig. 1, and Fig. 6 is a diagram. FIG. FIG. 7 is an enlarged vertical sectional view showing the main part of a second embodiment of the present invention.

  First, the first embodiment will be described. In FIG. 1, the dredged sediment transport system includes dredged sediment 1 generated by dredging work performed in a dam D as a large-capacity reservoir in a high place away from the sea O and into which water of the river R flows. It is used to transport from D to the sea O or the river R nearby by using gravity.

  This system includes a siphon pipe S that sucks dredged sand 1 of dam D together with water by siphon action, and a fluid containing dredged sand 1 and water that is connected to the downstream end of the siphon pipe S and sucked out by the pipe S. A natural flow path P that naturally flows down to the sea O or a river R near it by using gravity, and a water R separated from the fluid that has flowed through the natural flow path P, and a river R near the sea O And water / sediment separation processing means SE capable of temporarily storing the remaining dredged soil 1 and recovering at least a part thereof.

  In the illustrated example, the siphon pipe S is provided on a dredger work ship B that can be arbitrarily moved on the reservoir water surface of the dam D, and a movable suction pipe U in which the suction port Ue can be raised and lowered in water, and the movable suction pipe U The other end is connected to the downstream end, and the other end is provided on the downstream side of the dam D and at a position lower than the dam D. The movable suction pipe U and the transport pipe A cooperate with each other to form a siphon pipe S.

  Thus, the suction port Ue of the movable suction pipe U faces the sediment 1 or the vicinity of the bottom of the dam D, and the water suction pump (not shown) on the dredger work boat B exhibits a priming function so that the siphon pipe S Start siphoning. As a result, the siphon pipe S can suck up the sediment 1 from the bottom of the dam together with the water from the suction port Ue, and can gradually and continuously flow through the pipe to the relay rod Pm0.

  Further, in the middle of the siphon tube S, an open / close valve (not shown) capable of interrupting the siphon action by interrupting the tube at any time and a siphon of the siphon tube S by mixing air into the tube. Air-mixing means (not shown) for adjusting the suction force by the action is provided. Further, the dredger work ship B is provided with drive means 2 capable of moving the suction port Ue of the movable suction pipe U up and down to an arbitrary height, and propulsion means for causing the work ship B to travel on its own (see FIG. (Not shown) is also provided.

  The relay dredging Pm0 temporarily stores the dredged soil 1 and water containing the dredged soil 1 that have flowed down naturally from the siphon pipe S and can be gradually discharged to the downstream side. This is basically the same as the relay rod Pm provided in the natural flow path P described later. That is, the main body 3 is formed in a large-capacity water tank shape and is fixed on the ground, and a siphon tube S (conveyed in the illustrated example) is provided at the inlet 3i that is opened at a relatively high position of the main body 3. The downstream end of the pipe A) is connected, and the upstream end of the pipeline Pp located at the uppermost stream in the natural flow path P is connected to the outlet portion 3o opened at a relatively low position of the main body 3 of the pipe A). In addition, on the inlet 3i and outlet 3o of the bag main body 3, on-off valves Vi and Ve are respectively provided so that each can be opened and closed individually.

  The natural flow path P is interposed between a plurality of pipelines Pp, which are arranged in tandem with each other, and the adjacent pipelines Pp, Pp, and the dredged sand that has flowed down from the upstream pipeline Pp. 1 and a relay rod Pm that temporarily stores a fluid containing water and can be gradually discharged to the downstream pipeline Pp. The relay rod Pm should ensure smooth natural flow of the fluid in each pipeline Pp based on the total length of the natural flow path P and the height difference between the upper and downstream ends of the natural flow path P. A plurality of them are installed at an appropriate distance and with an appropriate height difference, but needless to say, the downstream relay rod Pm is placed at a lower position. Each pipeline Pp is basically arranged in a downward slope or horizontally, but a part of the pipeline Pp may be an upward slope depending on the terrain on the way.

  One pipeline Pp connecting two adjacent relay rods Pm is configured by connecting a plurality of pipeline elements 4 arranged in series with each other in series, and at least a part of the pipeline Pp is connected. The pipeline element 4 is supported by a concrete support frame 5 that is erected and fixed on the ground at intervals in the length direction of the pipeline Pp.

  Each relay rod Pm has basically the same structure as the relay rod Pm0 at the downstream end of the siphon pipe S, and the downstream end of the upstream pipeline Pp is connected to the inlet portion 3i of the rod body 3. An upstream end of the downstream pipeline Pp is connected to the outlet 3e. The inlet portion 3i and the outlet portion 3e are provided with on-off valves Vi and Ve, respectively.

  At least a part (all in the illustrated example) of the relay rods Pm is provided with microbubble supply means M for supplying innumerable microbubbles (air) having a diameter of 100 μm or less inside the pipeline Pp. The The microbubble supply means M generates a mixed phase flow in which fine bubbles are sufficiently dispersed and mixed in the pump 6 that pumps water from the relay rod Pm and pressurizes it, and in the water pressurized by the pump 6. A multiphase flow generator 7 and a pipe 8 that joins the multiphase flow generated in the multiphase flow generator 7 to a downstream pipeline Pp and mixes fine bubbles with the fluid flowing in the pipeline Pp. . Incidentally, such a multi-phase flow generator for mixing a large amount of fine bubbles in water is conventionally known and has already been mass-produced industrially (for example, JP 2000-447 A, JP 7-265057 A). (See the official gazette).

  The fine bubbles are so-called “micro bubbles”, and not only the macro-sized bubbles are reduced, but also exhibit various physicochemical properties due to the size effect. For example, these fine bubbles rise very slowly as if the soot remains stationary in water, and the bubbles exhibit excellent uniformity and dispersibility in water. Furthermore, the gas absorption efficiency in water is high and oxygen is dissolved. There is a feature that the amount can be increased quickly. And, when such countless fine bubbles are mixed and dispersed in the fluid containing dredged sand and water in the pipeline Pp, the frictional resistance between the fluid and the inner surface of the pipeline Pp is effectively increased. In addition, the durability of the pipeline Pp can be improved, and the density of the fluid can be reduced, and the fluid can flow smoothly even with a relatively small height difference. In addition, since the aerobic microorganisms in the fluid can be sufficiently brought into contact with oxygen in the fine bubbles and the microorganisms can be activated, the odor of the fluid when reaching near the sea O Since the turbidity is improved and the amount of dissolved oxygen is increased, the quality of water discharged into the sea O is improved, which is advantageous for environmental measures.

  The micro-bubble supplying means M may be provided on the dredger work ship B or on the relay dredger Pm0 provided at the downstream end of the siphon pipe S, so that the inside of the siphon pipe S or the most upstream pipeline Pp The fine bubbles can also be dispersed and mixed in the fluid containing the dredged sand 1 and water flowing inside.

  Next, the structure of the water / sediment separation means SE will be described with reference to FIGS. This water / sediment separation processing means SE is arranged continuously to the downstream end of the most downstream pipeline Pp of the natural flow path P, and in the illustrated example, is arranged at the riverbed 10 at the estuary Re.

  The water / sediment separation treatment means SE receives the dredged sand 1 flowing down via the natural flow path P and a fluid containing water and precipitates dredged sand 1 in the fluid. A3 is arranged so that the supernatant water in the fluid in each of the settling tanks A1 to A3 can be sequentially overflowed to the downstream settling tank, and the supernatant water overflowed from the most downstream settling tank A3 The ocean O is discharged directly.

  The plurality of settling tanks A1 to A3 are configured in a relatively shallow water tank shape with their upper surfaces opened, and are arranged in series in the river bed 10 near the estuary Re from the upstream side to the downstream side sequentially. Is done. The weirs 11 to 13 provided on the sea sides of the settling tanks A1 to A3 are formed so as to be lower on the downstream side. Sediment begins to settle.

  Next, the operation of this embodiment will be described. When hitting the bottom of the dam D, the dredger B is assembled around the dam D and floated on the surface of the dam D. Next, the tip of the movable suction pipe U is lowered from the dredger work ship B, and the suction port Ue at the tip of the movable suction pipe U faces the sediment layer on the bottom of the water. In this state, the siphon action of the siphon pipe S is started by a priming action by a water pump (not shown) connected to the siphon pipe S.

  Once the siphon action is started, the siphon action continues even if the water absorption pump is stopped. By the siphon action, the sediment 1 on the bottom of the dam D is sucked up together with the water, and the relay dredging just downstream of the dam D is obtained. Discharge gradually and continuously into Pm0. As the dredging work progresses, the position of the dredging vessel B is moved little by little, and thus the sediment 1 on the bottom of the dam D can be efficiently spread over almost the entire bottom of the bottom of the dam D with less energy and cost. It becomes possible.

  The fluid containing dredged sand 1 and water that has flowed into the first relay dredger Pm0 through the siphon pipe S is a part of dredged sediment 1 deposited and deposited in the relay dredger Pm0, and the remaining dredged sand 1 and The fluid containing water is discharged from the outlet portion 3e to the natural flow path P (uppermost pipeline Pp) of the present invention, and naturally flows down the natural flow path P gradually and continuously by gravity.

  While the fluid containing dredged soil 1 and water naturally flows down the natural flow path P, the fluid that has flowed down the upstream pipeline Pp and reached the next relay rod Pm A part of dredged sand 1 precipitates and accumulates in Pm0, and the remaining fluid containing dredged sand 1 and water is discharged into the pipeline Pp on the downstream side from the outlet 3e, and gravity flows in the pipeline Pp. It flows down naturally. In this case, it is possible to adjust the amount of fluid flowing into the relay rods Pm0 and Pm by adjusting the opening of the on-off valve Vi on the inlet side of each relay rod Pm0 and Pm. By adjusting the opening degree of the opening / closing valve Ve on the outlet side of Pm, it is possible to adjust the flow amount of the fluid to the downstream pipeline Pp.

  Thus, the fluid containing dredged soil 1 and water gradually moves downstream by repeating the above process in each relay dredger Pm, and finally the water / sediment separating means SE in the riverbed 10 near the estuary Re. To reach. In this water / sediment separation means SE, the fluid is sequentially received by the plurality of settling tanks A1 to A3 arranged in series along the river flow direction on the river bed 10, and the dredged soil 1 in the fluid is received. The supernatant water in the fluid in each of the sedimentation tanks A1 to A3 sequentially overflows to the downstream sedimentation tank, and finally the supernatant water overflowed from the most downstream sedimentation tank A3 is discharged directly into the sea O. Is done. In this case, since the sediments with finer particle sizes are deposited and deposited in the sedimentation tanks A1 to A3, the sediments 1 stored in the sedimentation tanks A1 to A3 are externally deposited. It can be collected without difficulty, and can be effectively used for construction materials, agricultural materials, and other uses according to the particle size. By collecting and collecting a part or all of the dredged soil 1 in the settling tanks A1 to A3 in this way, only relatively clean water with little or no dredged soil 1 can be discharged into the sea O. It is effective in preventing water pollution.

  By the way, it is possible to collect the dredged sand 1 in the middle of at least some of the relay dredgers Pm0, Pm... Upstream from the water / sediment separating means SE.

  That is, the sediment 1 deposited and accumulated in each of the relay rods Pm0, Pm can be easily collected and collected from each of the relay rods Pm0, Pm with the upper surface open, and it can be collected for construction materials and agriculture. Since it can be reused for materials and other purposes, the pipeline Pp downstream of each relay dredging Pm0, Pm is released with a relatively clean fluid containing dredged sand and water with a reduced content of dredged sand 1. Therefore, in combination with the separation and recovery effect of dredged soil 1 by the water / sediment separation means SE at the most downstream, the water discharged to the sea O can be sufficiently purified, More effective in preventing pollution.

  As described above, according to the present embodiment, the dredged sand 1 of the dam D located at a high place away from the sea O is sucked together with water by the siphon action of the siphon pipe S, and then to the sea O via the natural flow path P. Since it is allowed to flow down naturally, the dredged soil of dam D can be transported to the sea O without any difficulty using gravity, and energy saving and cost reduction for the transportation can be achieved. There is no worry of polluting the water area with dredged soil or affecting the ecosystem, and there is no risk of inconveniences such as traffic congestion, air pollution, and vibration noise as in the case of transportation by dump truck. Further, the natural flow path P is configured by connecting adjacent ones of a plurality of pipelines Pp arranged in tandem with a relay rod Pm, so that the pipeline Pp is compared with the case where there is no relay rod. Since the internal pressure can be sufficiently reduced and the durability thereof is increased, and maintenance of the pipeline Pp can be performed in units of the pipeline Pp divided by the relay rod Pm, the maintenance work becomes relatively easy.

  In addition, the water / sediment separation processing means SE connected to the downstream end of the natural flow path P is located upstream of the river bed 10 near the estuary Re in a state where the plurality of sedimentation tanks A1 to A3 constituting each of the natural flow path P are open. Since it is arranged in series in order from the downstream side to the downstream side, relatively large sedimentation tanks A1 to A3 can be arranged in many stages using the wide space of the riverbed 10 and the water purification function is increased accordingly. be able to. In addition, when the riverbed 10 at the estuary Re is submerged due to flooding, the sediment in the sedimentation tanks A1 to A3 is washed away into the sea O by the muddy flow of the river. Don't worry.

  FIG. 7 shows a main part of the second embodiment of the present invention. In this embodiment, a fluid containing water and dredged soil that has been sucked out by a siphon pipe S ′ from a dam D ′ as another large-capacity reservoir in the vicinity thereof is supplied into at least some of the relay dredging Pm. . For this purpose, the second main entrance 3i 'for allowing the dredged sand 1' of the dam D 'to flow in via the siphon pipe S' is added to the main body 3 of the relay dredger Pm near the downstream of the dam D '. In addition, the second inlet 3i ′ is also provided with an on-off valve Vi ′. The other structure of the second embodiment is basically the same as that of the first embodiment.

  Thus, in the second embodiment, the same effect as that of the first embodiment can be achieved and the fluid containing dredged sand 1 and water from the other dam D 'is received in the relay rod Pm. Can do. And the dredged sands 1 and 1 'from both dams D and D' can be easily merged at the relay dredger Pm, and both can naturally flow down to the sea O side using the downstream pipeline Pp. . In the second embodiment, the structure of the siphon tube S ′ is shown in a simplified manner for simplification of illustration. However, the other dams D ′ in the second embodiment also have the same structure as that of the dam D. A large dredging work similar to the dredging in the dam D may be performed using the dredging work boat B used in the above. In the second embodiment, when dredging the other dam D ', the pumped water and dredged soil 1' are supplied into the relay dredger Pm without using the siphon pipe S '. Good.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various design change can be performed.

  For example, in the above-described embodiment, the water / sediment separation processing means SE has shown that the supernatant water overflowed from the most downstream settling tank A3 is directly discharged into the sea O. In the present invention, the supernatant water is used. You may make it discharge | release to the river R near the sea O, for example, the river mouth Re.

  In the above embodiment, the water / sediment separation means SE is provided in the riverbed 10 near the river mouth Re. However, in the present invention, it is not always necessary to provide it in the riverbed, and at least the sea O or the river R near it. Any place where it can be discharged directly into the sea.

  Moreover, in the said Example, although what was made to flow all the water in each relay rod Pm and Pm0 downstream was shown, in this invention, the hydroelectric power generation facility using the fall water flow from the dams D and D 'is shown. A pumping pump driven by the electric power generated by the pump is provided, and at least a part of the water in the relay rods Pm, Pm0 near the dams D, D ′ is appropriately transferred to the dams D, D ′ side by the pumping action of the pumps. You may make it return. In this case, the pump 6 of the microbubble supply means M may be driven by the electric power.

Whole schematic longitudinal cross-sectional view which shows the outline | summary of the dredged sand transport system which shows 1st Example of this invention Enlarged view of the part indicated by arrow 2 in FIG. Fig. 3 is an enlarged view of the portion indicated by the arrow 3 in Fig. 1. 4-4 enlarged sectional view of FIG. Enlarged view of the part indicated by arrow 5 in FIG. Plan view from arrow 6 in FIG. Main part enlarged longitudinal sectional view showing a second embodiment of the present invention

Explanation of symbols

A1 ~ A3 ・ ・ Settling tank D ・ ・ ・ Dam (large capacity reservoir)
D '... Dam (other large-capacity reservoir)
M ··· Microbubble supply means O · · · Sea P · · · Natural flow path Pp · · · Pipeline Pm · · · Relay R · · · River Re ...・ Siphon tube SE: Water / sediment separation processing means Vi, Ve ... Opening / closing valve 1 ... Sediment sand 1 '... Sediment sand 3i ... Inlet part 3e ... Outlet part 10 ... Riverbed

Claims (8)

The high-capacity reservoir (D) dredged sand (1) at a high altitude away from the sea (O) flows from the reservoir (D) to the sea (O) or nearby river. (R) a dredged sand transport system,
A siphon tube (S) that siphons dredged sand (1) of the large capacity reservoir (D) with water,
Gravity is applied to fluids containing dredged soil (1) and water sucked out from the siphon tube (S) to the ocean (O) or nearby river (R). And at least a natural flow path (P) for natural flow,
The natural flow path (P) is interposed between a plurality of pipelines (Pp) arranged in tandem with each other and adjacent pipelines (Pp) from the upstream pipeline (Pp). A system for transporting dredged soil, comprising a relay dredger (Pm) that temporarily stores the fluid flowing down and can be discharged into a pipeline (Pp) on the downstream side.   Water can be separated from the fluid flowing down through the natural flow path (P) and discharged into the sea (O) or the river (R) nearby, and the remaining dredged sand (1) is temporarily removed. Water / sediment separation processing means (SE) that can store and recover at least a part of the water / sediment separation processing means (SE) is disposed continuously to the downstream end of the most downstream pipeline (Pp) of the natural flow path (P). The dredged sand transport system according to claim 1, characterized in that The water / sediment separation means (SE) receives a fluid that has flowed down through the natural flow path (P), and precipitates dredged sand (1) in the fluid (A1 to A1). A3) is arranged and configured so that the supernatant water in the fluid in each of the settling tanks (A1 to A3) can be sequentially overflowed to the downstream settling tank,
The dredged sand transport system according to claim 2, wherein the supernatant water overflowed from the most downstream sedimentation tank (A3) is discharged into the sea (O) or a river (R) nearby. .   Each of the plurality of sedimentation tanks (A1 to A3) has an open upper surface, and is arranged in series from the upstream side to the downstream side in the river bed (10) near the estuary (Re). The transport system for dredged sand according to claim 3.   Each relay rod (Pm) includes an inlet portion (3i) to which an upstream pipeline (Pp) is connected and an outlet portion (3e) to which a downstream pipeline (Pp) is connected. The system for transporting dredged sand according to any one of claims 1 to 4, wherein the inlet part (3i) and the outlet part (3e) are provided with on-off valves (Vi, Ve), respectively.   The microsiphon supply means (M) for supplying innumerable fine bubbles to the inside of the siphon tube (S) or at least a part of the pipeline (Pp) is provided. The dredged soil transport system according to any one of 5 above. A method for transporting dredged sand using the transport system according to claim 1,
The dredged material sand characterized in that at least a part of the dredged material sediment (1) precipitated and deposited in at least one relay dredger (Pm) is collected so as not to flow into the downstream pipeline (Pp). Transportation method. A method for transporting dredged sand using the transport system according to claim 1,
At least a part of the relay dredger (Pm) is supplied with a fluid containing water sucked from another large-capacity reservoir (D ′) in the vicinity thereof and dredged soil (1 ′). Transportation method of earth and sand.

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