JP2006118123A - Sediment transport method in water reservoir and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sediment transport method in a water reservoir and its device, capable of transporting earth and sand without motive power or with low motive power, without requiring large artificial energy for transporting the deposited sediment. <P>SOLUTION: An initial water flow is formed by a high pressure water pump 22 in an earth and sand transport pipe 21 arranged in the water reservoir 8 with a head provided. A sediment flow having density higher than surrounding water is formed by inputting earth and sand dredged from a chute 22 on the upper end 21a. This earth and sand flow is controlled and maintained by a pump control device 27, and the dredged earth and sand is inputted in the chute 22 to be transported to a discharge port of the other end part 21b, and the sediment flow is maintained, and the sediment can be transported without motive power or with low motive power. Thus, the deposited sediment is effectively made to flow out to save the artificial energy by effectively using a sand removal facility 4, and an effective water storage quantity can be secured, and the earth and sand can also be supplied to the downstream side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for transporting earth and sand in a reservoir, and allows the earth and sand dredged in a dam reservoir to be transported with no power or low power so that the sand discharge facility of the dam can be used effectively. It is a thing.

  In a reservoir formed by damming a river with a dam for flood control, water use, or power generation, the transported sediment gradually accumulates.

  This sedimentation is assumed in advance, and generally the height and amount deposited in 100 years is the planned sedimentation level and the planned sedimentation amount as shown in Fig. 4, but when sediments accumulate in the reservoir beyond these, As a result, the amount of effective water storage that can be used effectively is reduced, and the supply of sediment to the downstream is reduced, resulting in river bed degradation and coastal erosion (sand beach thinning).

  For this reason, the sedimentary sediment is sucked up with a bucket or dredging pump and then lifted to the surface of the water and transported with a truck or the like to recover the effective water storage amount or below the planned sediment level of Dam 1 Is provided with a sand removal facility 4 consisting of a sand discharge pipe 2 and a sand discharge gate 3, and when the deposition level becomes higher than the sand discharge pipe 2, the sand discharge gate 3 is opened to allow the accumulated sediment to flow out. Yes.

  However, in order to recover the effective water storage capacity, the method of transporting dredged soil by truck, etc. requires artificial energy to move the sediment and costs, and the sediment cannot be supplied downstream.

  On the other hand, the method of flowing sediment using the sand removal facility 4 is superior to the dredged sediment transport method in that it does not require artificial energy and in the supply of sediment in the downstream, but it is shown in FIG. As shown, only the earth and sand near the mouth of the sand removal pipe 2 can be flowed.

  Therefore, although it is earth and sand transportation in the case of reclamation with dredged soil instead of dredging at the dam, Patent Document 1 discloses that the earth and sand dredged by the dredging pump is made into a slurry and is disposed at a distant disposal site using a transport pipe. In the case of transportation, it is disclosed that a plug flow is generated by sending compressed air when sedimentation of sediment occurs and it becomes difficult to flow, and the sediment slurry is transported without using a relay pump.

  Further, as a method for transporting earth and sand to the vicinity of the mouth of the sand pipe in order to effectively use the sand discharge facility of the dam, as shown in FIG. Is collected by a compressor 5 driven by a water turbine, and high-pressure air is produced, and this is supplied to the inlet end of the reservoir 8 of the sediment transport pipe 7 by an air pipe 6 to generate an action of an air lift pump. It is disclosed to transport with a sediment transport pipe.

Furthermore, in Patent Document 3, as shown in FIG. 6, the upper surface of sedimentary sediment in the reservoir 8 is covered with a water-impervious sheet 9 except for a water supply opening, and flows with water that has entered between the sedimentary sediment and the impervious sheet 9. It is disclosed that the earth and sand are formed to flow out.
JP 2004-60330 A Japanese Patent Laid-Open No. 11-93147 JP 2003-261924 A

  However, as in Patent Document 1, although sedimentation of sediment can be eliminated with a plug flow by injecting compressed air, the energy (power) of the dredging pump will be used for transporting the sediment, There is a problem that requires a large amount of artificial energy for transporting earth and sand.

  In addition, as in Patent Document 2, in the case of transporting earth and sand by collecting the energy of discharged water and supplying high-pressure air to generate the action of an air lift pump, the compressor is always used while transporting earth and sand is required. There is a problem that it must be operated and artificial energy is always required.

  Furthermore, as in Patent Document 3, when transporting earth and sand by covering the surface of sedimentary sediment in the reservoir with a water-impervious sheet, a huge impermeable sheet is required, although artificial energy is not required. Therefore, there is a problem that costs are increased.

  The present invention has been made in view of the problems of the prior art, and does not require large artificial energy to transport the accumulated sediment, and can be transported with no power or low power. It is intended to provide a transportation method and apparatus.

  As a result of intensive studies to solve the problems of the above-mentioned conventional technology, the sand discharge pipe of the sand removal equipment to transport the sediment is located deep in the lower part of the dam, while the place where the sediment is dredged is The present invention has been completed by finding shallow places on the upstream side away from the sea, where there are large heads at these places, and transporting dredged soil using the energy of the heads.

  That is, for example, as shown in FIG. 3, when the entire straw filled with juice is sunk in a standing or slanted state in a container containing water, the juice flows out from the lower end of the straw However, as with this phenomenon, if a sediment transport pipe is installed in a state where there is a drop, and if a sediment flow that is denser than the surrounding water (storage water) is maintained and formed, the sediment will be powered Or it can be transported with low power.

  Based on such a point of view, the method for transporting sediment in the reservoir according to claim 1 of the present invention provides the sediment transport by providing a drop at the bottom of the reservoir when transporting sediment deposited in the reservoir on the upstream side of the dam. After placing the pipe and generating an initial water flow in the sediment transport pipe, the earth and sand is poured from the inlet provided at the upper end of the sediment transport pipe to form a sediment flow having a density higher than water in the pipe. It is characterized in that the earth and sand flow is continued while the earth and sand are being introduced from the inlet, and the earth and sand are transported to the discharge outlet at the lower end of the earth and sand transport pipe.

  According to this method of transporting sediment in the reservoir, an initial water flow is formed in the sediment transport pipe installed with a drop in the reservoir, and dredged sediment is introduced from the inlet at the upper end, which is higher in density than the surrounding water. A debris flow is formed and transported by throwing in the debris drowned to sustain this debris flow, and the debris flow can be transported with no power or low power in a sustained debris flow.

  Moreover, in the sediment transport method in the reservoir of the present invention, in addition to the above configuration, when the drop between the input port and the discharge port of the sediment transport pipe is insufficient for sustaining the sediment flow, the sediment transport The sediment flow may be maintained while supplying the auxiliary water flow to the pipe, and the initial water flow is formed by connecting the discharge side of the dredging pump to the inlet of the sediment transport pipe. Alternatively, the discharge side of the dredge pump may be connected to form the initial water flow, and after the sediment flow has been maintained, the dredge pump may be bypassed to connect the suction side to the sediment transport pipe.

Furthermore, the sediment transport device in the reservoir according to claim 5 of the present invention is a device for transporting the sediment deposited in the reservoir on the upstream side of the dam, and is arranged with a drop at the bottom of the reservoir and is arranged at the upper end. An earth and sand transport pipe with an inlet at the lower end and an outlet at the lower end;
The water flow generating means for generating an initial water flow in the earth and sand transport pipe, and the water flow generating means generates an initial water flow in the earth and sand transport pipe, and then the sand and sand is introduced from the inlet to have a higher density than the water in the pipe. And a control means for controlling the water flow generating means for continuously forming the water flow.

  According to the sediment transport device in the reservoir, an initial water flow is formed by the water flow generating means in the sediment transport pipe installed with a drop in the reservoir, and the dredged sediment is introduced from the inlet at the upper end, and the surrounding water is A more dense debris flow is formed, and this debris flow is maintained by the control means that controls the water flow generation means, and the dredged sediment is transported to the discharge port by being poured into the discharge port. The flow is maintained so that sediment can be transported with no power or low power.

  Further, the sediment transport apparatus in the reservoir of the present invention, in addition to the above configuration, the water flow generating means, in addition to the generation of the initial water flow, the difference between the inlet and the discharge port of the sediment transport pipe is the sediment It is possible to supply an auxiliary water flow for the formation of the earth and sand flow when it is insufficient for the sustainability of the flow, or a certain amount of the earth and sand to be added to the downstream side of the inlet at the upper end of the earth and sand transport pipe An earth and sand feeder that can be supplied is provided, or the water flow generating means is configured by connecting the discharge side of the dredging pump to the inlet of the earth and sand transport pipe, or the suction pipe of the dredge pump and the earth and sand transport A bypass pipe may be provided between the pipe and the earth and sand flow after the dredging pump is bypassed to supply earth and sand from the suction pipe.

  According to the method for transporting sediment in the reservoir according to claim 1 of the present invention, an initial water flow is formed in the sediment transport pipe provided with a drop in the reservoir, and the sediment deposited from the inlet at the upper end is introduced. It is possible to form a sediment flow that is denser than the surrounding water. By introducing the sediment that has been drowned to sustain this sediment flow, the dredged sediment can be transported with no or low power. can do.

  Further, according to the sediment transport method in the reservoir according to claim 2 of the present invention, even when the drop between the inlet and the discharge port of the sediment transport pipe is insufficient for sustaining the sediment flow, By maintaining the sediment flow while supplying the auxiliary water flow to the sediment transport pipe, it is possible to transport the dredged sediment with low power, and according to the invention of claim 3, the initial water flow is It can be formed by connecting the discharge side of the dredging pump to the inlet of the earth and sand transport pipe, and can be simplified by omitting a device for forming an initial water flow. By connecting the discharge side of the pump to form the initial water flow, after the sediment flow has been sustained, the dredging pump is bypassed and the suction side is connected to the sediment transport pipe, so that energy for dredging is also required Without dredging, transporting dredging and sediment It can be carried out layer efficiently.

Further, according to claim 5 of the present invention, there is provided a sediment transport apparatus in a reservoir, wherein an initial water flow is formed by a water flow generating means on a sediment transport pipe provided with a drop in the reservoir, and dredged from an inlet at an upper end. To form a sediment flow that is denser than the surrounding water, and this sediment flow is maintained by the control means that controls the water flow generation means. By doing so, dredged soil can be transported to the discharge port.
Thereby, earth and sand can be transported with no power or low power.

  Moreover, according to the sediment transport apparatus in the reservoir according to claim 6 of the present invention, the water flow is generated even when a drop between the input port and the discharge port of the sediment transport pipe is insufficient for sustaining the sediment flow. By making it possible to supply auxiliary water flow in addition to generation of the initial water flow by means, it is possible to transport dredged sediment with low power, and according to the invention of claim 7, the upper end of the sediment transport pipe By providing an earth and sand feeder capable of supplying a certain amount of the earth and sand to be introduced on the downstream side of the inlet, it is possible to maintain the earth and sand flow more easily, and according to the invention of claim 8, 10. The apparatus for forming an initial water flow can be simplified by configuring the water flow generating means by connecting a discharge side of a dredge pump to the input port of the earth and sand transport pipe. In the present invention, the suction pipe of the soot pump Energy for dredging is also required by providing a bypass line that bypasses the dredging pump and feeds sediment from the suction pipe after the mud flow is sustained between the sediment transport pipe Instead, dredging and sediment transport can be performed more efficiently.

  By realizing this method, in the reservoir where only the sand near the drainage pipe throat was previously discharged, the sediment was transported from the upstream etc. to the dent after the sand removal to a position higher than the planned sedimentation surface. It becomes possible to discharge afterwards, and maintenance or recovery of the effective water storage capacity of the reservoir can be realized at low cost.

  The operation method for this purpose is to drain the sediment stored near the drainage pipe mouth through the drainage gate when the river is flooded due to rain, etc., and open the next drainage gate such as when there is no water increase. During this period, the upstream sediment can be transported to the dent after the sand removal by this method.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram according to an embodiment of an earth and sand transport device in a reservoir according to the present invention.

  In the reservoir 8 dammed up by the dam 1 where the sediment transport device 20 in the reservoir is installed, the sand discharge pipe 2 and the sand discharge are provided as a sand discharge facility 4 for discharging the accumulated sediment S to the downstream side of the dam 1. A gate 3 is provided, and by opening the sand removal gate 3, at least sedimentary sediment S in the vicinity of the stagnation mouth can be discharged through the sand removal pipe 2.

  The earth and sand transporting device 20 provided in such a reservoir has an earth and sand transport pipe 21 on one side 21a and the other end 21b such that the earth and sand transport pipe 21 is substantially perpendicular to the dam 1 on the sediment earth and sand S deposited on the bottom of the reservoir 8. It is installed so that a drop is formed in between, one end 21a is in the vicinity of the relatively shallow dredging area upstream, and the other end 21b is stagnated in the sand discharging pipe 2 of the sand discharging facility 4 to which dredged sand is transported. Arranged near the mouth.

  In the earth and sand transport pipe 21, one end 21a on the upstream side is used as an inlet for introducing earth and sand dredged by, for example, the bucket dredger B, and a funnel-shaped chute 22 is provided to facilitate the introduction.

  In such a sediment transport pipe 21, at least one end portion 21a and the other end portion 21b are fixed to the bottom of the reservoir 8 by some fixing means such as an anchor, but the intermediate portion is not particularly required to be fixed, There may be up and down, and it may be connected by a flexible joint so as to correspond to the unevenness of the bottom of the reservoir 8.

  Thus, even if the middle portion is not fixed, the flow velocity at the bottom of the reservoir 8 is small even at the time of flooding, and there is almost no risk of the sediment transport pipe 21 flowing, and no sediment is deposited on the sediment transport pipe 21. there is no problem.

  This earth and sand transport pipe 21 is provided with a high pressure pump 23 and a jet nozzle 25 connected by a hose 24 as water flow generating means for generating an initial water stream. For example, the jet nozzle 25 is the other end 21 b of the earth and sand transport pipe 21. A high-pressure pump 23 is installed on the water surface or on the lakeside so that high-pressure water can be jetted toward the other end in a nearby pipe.

  The jet nozzle 25 of this water flow generating means is not limited as long as it can generate a water flow in the sediment transport pipe 21 with high-pressure water, and its attachment position is not limited to the vicinity of the other end 21b, but an intermediate portion or one upstream end. It may be near the portion 21a.

  Further, the chute 22 at one end portion of the earth and sand transport pipe 21 does not need to be underwater as in the illustrated example, and may be on the water surface, but it is necessary to form a water flow or a sand and sand flow in the earth and sand transport pipe 21. Therefore, it is necessary to be able to supply sufficient water into the sediment transport pipe 21 such as in the vicinity of the downstream side of the chute 22.

  Furthermore, in the sediment transport apparatus 20 in the reservoir, pressure detectors 26 are provided in the vicinity of the one end 21a and the other end 21b of the sediment transport pipe 21 in order to detect the occurrence of the initial water flow and the sediment flow, A detection signal is input to a pump control device 27 which is a control means of the high-pressure pump 23 constituting the water flow generation means, and the operation / stop of the high-pressure pump 23 can be controlled based on the detection result.

  It should be noted that a lid may be provided at one end 21 a of the earth and sand transport pipe 21 so that earth and sand do not accumulate inside the earth or sand, and a lid may be provided on the chute 22 while the earth and sand are not transported by dredging.

The earth and sand transport method will be described together with the operation of the earth and sand transport device 20 in the reservoir configured as described above.
If the sediment transport pipe 21 is merely filled with sediment, the sediment does not move unless the sediment transport pipe 21 is inclined at an angle of repose of the sediment (usually 30 degrees or more). Then, since the bottom is not so inclined, the earth and sand do not move in a natural state.

  Therefore, in the earth and sand transport device 20, the high pressure water pump 23 constituting the water flow generating means is operated to generate a water stream in the earth and sand transport pipe 21 through the jet nozzle 25.

  In a state where this water flow is generated in the earth and sand transport pipe 21, an appropriate amount of earth and sand dredged by the bucket dredger B is started from the chute 22 of the one end 21a.

  Then, the introduced earth and sand flows so as to be sucked into the water stream, and an earth and sand stream is formed in the earth and sand transport pipe 21.

  Since the sediment flow in the sediment transport pipe 21 acts as a fluid having a higher density than water as a whole, a drop is formed in advance between the one end 21a and the other end 21b of the sediment transport pipe 21. It tries to flow downwards and creates a sediment flow in the pipe.

  Therefore, when the sediment flow flows out in the entire sediment transport pipe 21, the sediment flow can be maintained by the drop of the sediment transport pipe 21 if an appropriate amount of sediment is supplied from the chute 22 without jetting high-pressure water. Become.

  Although not shown in the figure, a sediment feeder may be installed between the chute 22 and one end 21a of the sediment transport pipe 21 so that dredged soil can be supplied from the chute 22 at a fixed amount. For example, a screw feeder may be used. Install.

  Therefore, it is possible to know whether or not a sediment flow has been formed by detecting the pressure difference between the two end portions 21a and 21b of the sediment transport pipe 21 with the pressure detector 26, and thereby the high pressure water pump 23 with the pump controller 27. Control to stop.

  As a result of a trial calculation of such a sediment transport method, for example, the pipe diameter of the sediment transport pipe is assumed to be 0.5 m, the pipe length is 1000 m, the drop is 50 m, and the sediment concentration is 10% (density is 1.15 kg / m 3). In this case, it was found that a sediment flow with an in-pipe flow rate of 1.6 m / s was generated in the sediment transport pipe, which was larger than the flow rate of 1.0 m / s required for sediment transport, and a sufficient flow rate could be secured.

  The dredged sand can be transported in such a manner as to maintain the sediment flow in the sediment transport pipe 21 that has been given a drop as described above, and only the high-pressure water pump 23 is operated to form an initial water flow. Dredged sand can be transported without the need for energy.

  In addition, when the drop of the earth and sand transport pipe 21 is small or when the piping distance is long, the loss of the flow becomes large, and a sufficient flow velocity sufficient to form a sediment flow in the earth and sand transport pipe 21 is ensured only by the head. There are cases where it is not possible.

  In such a case, in order to secure a flow rate necessary for transporting dredged soil, high pressure water injection may be continued by the high pressure water pump 23 which is a water flow generating means. Can be low-pressure water as compared with the case where the initial water flow is generated, and it is sufficient that the sediment flow can be sustained in cooperation with the drop of the sediment transport pipe 21.

  Even when the head of the sediment transport pipe 21 is small or the flow loss is large, the transport energy of dredged soil can be saved by the amount of the head energy compared to the case where the head energy is not used at all.

  Further, in this sediment transport method, the sediment concentration in the sediment transport pipe 21 is important for maintaining a stable sediment flow. If the sediment concentration becomes too small, the pressure difference due to the drop disappears, the flow velocity in the tube decreases and the sediment flows. However, if the sediment concentration becomes too high, the flow loss will increase and the sediment will not flow, and the sediment may clog the pipe. It is effective to provide an earth and sand feeder between one end 21a of the transport pipe 21.

  In order to operate this earth and sand feeder, artificial energy such as electric power is required, but even in this case, if all the energy required for dredged earth and sand transport is compared, it is possible to save by the use of the head.

  Next, another embodiment of the earth and sand transport device in the reservoir of the present invention will be described with reference to FIG.

  The earth and sand transport device 20A in the reservoir is applied to the case of dredging by the pump dredger P instead of dredging by the bucket dredger B. The same symbols are given to the parts common to the already explained apparatus, and the explanation is omitted. To do.

  Also in the earth and sand transport apparatus 20A provided in such a reservoir, the earth and sand transport pipe 21 is arranged on the sediment earth and sand S deposited on the ground at the bottom of the reservoir 8 in a direction substantially perpendicular to the dam 1 and the like. Sand is installed so that a drop is formed between the portion 21a and the other end 21b, the one end 21a is in the vicinity of the relatively shallow dredging area on the upstream side, and the other end 21b is the transport destination of dredged sand. They are arranged in the vicinity of the mouth of the sand discharge pipe 2 of the facility 4.

  The earth and sand transport pipe 21 is connected to the discharge pipe 31 of the pump dredger P in order to put the earth and sand collected at the upstream end portion 21a, and the earth and sand sucked by the dredge pump 33 from the suction pipe 32 is directly transported to the earth and sand. It can be put into the tube 21.

  As described above, at least one end 21a and the other end 21b of such a sediment transport pipe 21 are fixed to the bottom of the reservoir 8 by some fixing means such as an anchor. In addition, there may be some upper and lower sides, and it may be connected by a flexible joint so as to correspond to the unevenness of the bottom of the reservoir 8.

  In the sediment transport device 20A in the reservoir, the dredging pump 33 of the pump dredger P is also used as a water flow generating means for generating an initial water flow in the sediment transport pipe 21, and a special high pressure water pump or jet nozzle is used. Is not provided.

  The dredged pump 33 does not suck the sediment, but only the water is sucked to generate an initial water flow in the sediment transport pipe 21.

  Furthermore, also in the sediment transport apparatus 20A in this reservoir, pressure detectors 26 are provided in the vicinity of the one end 21a and the other end 21b of the sediment transport pipe 21 in order to detect the occurrence of the initial water flow and the generation of the sediment flow, A detection signal is input to the dredge pump controller 34 which is a control means of the dredge pump 33 constituting the water flow generating means, and the operation / stop of the dredge pump 33 can be controlled based on the detection result.

  Moreover, in the sediment transport apparatus 20A in this reservoir, after the initial water flow is generated, the dredged soil sucked by the dredging pump 33 is introduced into the sediment transport pipe 21 to form a sediment flow, but the sediment flow is maintained. After that, the sedimentary sediment is directly sucked by the pressure difference caused by the sediment flow, and a bypass pipe 35 is provided so that the dredged sand can be introduced directly into the sediment transport pipe 21 from the suction pipe 32, and the operation of the dredge pump 33 is stopped. The suction pipe 32 and the discharge pipe 31 are made to communicate with each other, and the dredging and dredged sand are transported using the head energy as suction energy. In this case, operation control of the soot pump 33 and switching control to the bypass pipe 35 are performed by the soot pump control device 34.

The earth and sand transport method will be described together with the operation of the earth and sand transport apparatus 20A in the reservoir configured as described above.
In this earth and sand transport apparatus 20A, the dredging pump 33 of the pump dredger P that constitutes the water flow generating means is operated to feed only water and generate a water stream in the earth and sand transport pipe 21.

  In a state where this water flow is generated in the earth and sand transport pipe 21, dredging is started by the dredge pump 33 of the pump dredger P, and an appropriate amount of dredged earth and sand is started to be introduced from one end 21a of the earth and sand transport pipe 21 through the discharge pipe 31. .

  Then, the introduced earth and sand flows so as to be sucked into the water stream, and an earth and sand stream is formed in the earth and sand transport pipe 21.

  The sediment flow in the sediment transport pipe 21 acts as a fluid having a higher density than water as a whole, and a drop is formed in advance between the one end 21a and the other end 21b of the sediment transport pipe 21. An attempt is made to flow downward, creating a stream of sediment in the tube, like juice in a straw submerged in a container.

  Therefore, when the sediment flow flows out in the entire sediment transport pipe 21, the sediment flow can be maintained by the drop of the sediment transport pipe 21 and the sediment can be transported by supplying an appropriate amount of sediment from the dredging pump 33.

  Therefore, the pressure detector 26 detects the pressure difference between the two end portions 21a and 21b of the sediment transport pipe 21 to know whether or not a sediment flow has been formed, and thereby the dredge pump controller 34 stops the dredge pump 33. In addition, the dredging pump 33 is bypassed and the dredged soil is switched to the bypass pipe 35 so that the dredged soil can be directly supplied to the sediment transport pipe 21.

  The dredged sand can be transported in such a manner as to maintain the sediment flow in the sediment transport pipe 21 that has been given a drop in this way, and only by operating the dredging pump 33 of the pump dredger P in order to form the initial water flow, It is also possible to use the head energy as suction energy, and transport dredging and dredged sand with no power or low power without the need for artificial energy.

  In addition, when the drop of the earth and sand transport pipe 21 is small or when the piping distance is long, the loss of the flow becomes large, and a sufficient flow velocity sufficient to form a sediment flow in the earth and sand transport pipe 21 is ensured only by the head. If this is not possible, as already described, in order to secure the flow rate necessary for transporting dredged sand, the dredging pump 33 of the pump dredger P, which is the water flow generating means, is operated so that water is supplied together with the sediment. Just do it.

  The water supply by the dredging pump 33 in this case only needs to be able to maintain the sediment flow in cooperation with the drop of the sediment transport pipe 21, and even if the sediment transport pipe 21 has a small drop or a large flow loss, the drop energy is reduced. Compared to the case where it is not used at all, the transport energy of dredged soil can be saved by the amount of head energy.

  According to the method and apparatus for transporting sediment in the reservoir, the sand removal facility 4 provided in the dam is effectively used to open the sand discharge gate 3 and the sediment sediment near the spillway is discharged from the sand discharge pipe 2. In combination with the transport of soil that has been drowned in this area, it is possible to efficiently drain sedimentary sediments efficiently by saving artificial energy and secure effective water storage, and also to supply sediments downstream. It becomes possible.

  In the above embodiment, the case where only one earth and sand transport pipe is provided has been described as an example. However, the present invention is not limited to this, and a plurality of earth and sand transport pipes may be installed. It is not limited to the case, and any direction may be used as long as a head can be secured.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram concerning one Embodiment of the earth-and-sand transport apparatus in the reservoir of this invention. It is a schematic block diagram concerning other one Embodiment of the earth and sand transport apparatus in the reservoir of this invention. It is explanatory drawing of the basic principle of the sediment flow generation of the sediment transport method in the reservoir of this invention. It is explanatory drawing of the reservoir of a dam, sand discharge equipment, and the sand discharge schematic diagram of the sand discharge pipe vicinity. It is a schematic block diagram of the earth and sand transport apparatus in the conventional reservoir. It is a schematic block diagram of the earth and sand transport apparatus in the other conventional reservoir.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dam 2 Sand discharge pipe 3 Sand discharge gate 4 Sand discharge facility 8 Reservoir 20, 20A Sediment transport device 21 in the reservoir 21 Sediment transport pipe 21a One end 21b Other end 22 Chute 23 High pressure water pump (water flow generating means)
24 hose 25 jet nozzle 26 pressure detector 27 pump control device (control means)
31 Discharge pipe 32 Suction pipe 33 Dredge pump 34 Dredge pump control device 35 Bypass pipe S Accumulated sediment B Bucket dredger P Pump dredger

Claims (9)

When transporting sediment deposited in the reservoir on the upstream side of the dam,
A sediment transport pipe is provided with a drop at the bottom of the reservoir, and an initial water flow is generated in the sediment transport pipe, and then sand is introduced into the pipe through an inlet provided at the upper end of the sediment transport pipe. A sediment flow having a density higher than that of water is formed in the water, and the sediment flow is continued while the sediment is being introduced from the inlet, and the sediment is transported to the discharge port at the lower end of the sediment transport pipe. How to transport sediment in the reservoir.   When the drop between the inlet and the outlet of the earth and sand transport pipe is insufficient for sustaining the earth and sand flow, the earth and sand flow is maintained while supplying an auxiliary water flow to the earth and sand transport pipe. The method for transporting earth and sand in a reservoir according to claim 1.   3. The sediment transport method in a reservoir according to claim 1 or 2, wherein the initial water flow is formed by connecting a discharge side of a dredging pump to the inlet of the sediment transport pipe.   The discharge side of the dredge pump is connected to form the initial water flow, and after the sediment flow is sustained, the dredge pump is bypassed and the suction side is connected to the sediment transport pipe. The method for transporting earth and sand in the reservoir according to claim 3. A device for transporting sediment deposited in a reservoir on the upstream side of a dam,
A sediment transport pipe provided with a drop at the bottom of the reservoir and provided with an inlet at the upper end and an outlet at the lower end,
Water flow generating means for generating an initial water flow in the sediment transport pipe;
A control means for controlling the water flow generating means for generating an initial water flow in the earth and sand transport pipe by the water flow generating means and then supplying the earth and sand from the inlet to continuously form a sand flow having a density higher than water in the pipe; A sediment transport device in a reservoir characterized by comprising:   In addition to the generation of the initial water flow, the water flow generating means can supply an auxiliary water flow for the earth and sand flow when a drop between the inlet and the outlet of the earth and sand transport pipe is insufficient for sustaining the earth and sand flow The earth and sand transport apparatus in the reservoir according to claim 5, wherein the apparatus is configured as follows.   The sediment transport apparatus in a reservoir according to claim 5 or 6, wherein a sediment feeder capable of supplying a certain amount of sediment to be introduced is provided downstream of the inlet at the upper end of the sediment transport pipe. .  The sediment transport apparatus in a reservoir according to any one of claims 5 to 7, wherein the water flow generating means is configured by connecting a discharge side of a dredging pump to the inlet of the sediment transport pipe. A bypass pipe is provided between the suction pipe of the dredging pump and the sediment transport pipe to bypass the dredging pump after the sediment flow has been maintained and supply the sand from the suction pipe. The earth and sand transport apparatus in the reservoir according to claim 8.

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