JP4411418B2 - Transportation method and apparatus for bottom sediment - Google Patents

Description

  The present invention relates to a method and an apparatus for transporting bottom sediment, and enables sediment collected on the bottom of a dam reservoir or the like to be collected and transported from a wide range with a simple structure.

  One of the cases where sediment deposited on the bottom of the water needs to be transported is sediment that gradually accumulates when it is transported to a reservoir formed by damming a river with a dam for flood control, water use, or power generation.

  This sedimentation is assumed in advance, and generally the height and amount deposited in 100 years are the planned sedimentation level and the planned sedimentation amount as shown in Fig. 5 (a). Accumulation of sediment reduces the effective amount of water that can be used effectively, reduces the supply of sediment to the downstream, and causes river bed degradation and coastal erosion (sand beach thinning).

  For this reason, the sediment is collected by sucking it with a bucket or dredging pump and fried on the surface of the water and transported by a truck to recover the effective water storage volume. A sand removal facility 4 comprising a sand discharge pipe 2 and a sand discharge gate 3 is provided below the planned sedimentation level of the body 1, and when the deposit level is higher than the sand discharge pipe 2, the sand discharge gate 3 is opened and deposited. Sediment is drained.

  However, in order to recover the effective water storage volume, the method of transporting dredged soil by truck, etc., requires artificial energy to move the sediment and costs, so it is economical to supply sediment downstream. Often difficult.

  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 artificial energy is not required and in terms of supplying sediment downstream, but in FIG. 5 (b). As shown, only the earth and sand near the mouth of the sand removal pipe 2 can be flowed.

  Therefore, in the method of inflowing sediment underwater using the hydrostatic pressure of Patent Document 1, as shown in FIGS. 6A and 6B, a pipe 5 with an opening is embedded in the sediment S, The opening of the end 5a is positioned in the water, and the lower end 5b is disposed so as to penetrate the dam 1 so that a hydrostatic pressure difference is generated, and water entering from the opening of the upstream end 5a enters the pipe 5 A method is disclosed in which the deposit S around the opening 5c is sucked into the pipe 5 while being sucked into the tube 5 by the negative pressure generated as it flows.

In the reservoir sand removal method of Patent Document 2, as a method of sand removal without using the sand discharge gate 3 of the dam 1, as shown in FIG. The suction pipe 7 is provided at the center of the back surface of the sheet-like member 6 and water is sucked from the center using a siphon phenomenon or the like, so that the space between the sheet-like member 6 and the accumulated earth and sand S is reduced. A method is disclosed in which a water flow is generated and the earth and sand are sucked and transported by the scavenging action (the action of sweeping away by the flow), thereby forming a mortar-shaped depression.
Japanese Patent Application Laid-Open No. 2002-294677 JP 2004-270256 A

  However, in the method of Patent Document 1, it is necessary to embed the pipe 5 with the opening 5c in the sediment earth and sand S. In the new dam, although it can be laid relatively easily by laying in advance at the bottom of the dam reservoir, For the dam, there is a problem that the pipe 5 cannot be easily laid because the accumulated earth and sand S must be dug.

  In addition, it is necessary to pass the dam dam body 1 through the downstream side 5b of the pipe 5 with the opening 5c, and it is difficult to install it unless it is a new dam. There is a problem that you have to do underwater piping work.

  Furthermore, the range in which sand can be discharged is only a fixed range along the pipe 5, and there is a problem that the pipe 5 must be branched or moved when attempting to discharge sand in a wide range.

  Further, in the method of Patent Document 2, since the sheet-like member 6 is laid on the surface of the accumulated sediment and sand is discharged, sand can be discharged even in an existing dam, and sand can be discharged at any place in the reservoir. Although sand can be discharged from a wide range according to the area of the sheet, for example, it is a difficult task to expand a large sheet-like member 6 having a diameter of 100 m in water or to move its laying position. is there.

  The present invention has been made in view of the problems of the prior art, and intends to provide a method and apparatus for transporting sediment deposited on the bottom that can collect and transport sediment deposited on the bottom in a wide range with a simple structure. Is.

  As a result of intensive investigations to solve the problems of the above-mentioned conventional technology, a pipe with an open bottom surface is placed on the surface of the accumulated earth and sand, a pipe with suction force such as a pump is connected to the base end, and water is sucked Then, the water flowing in the open pipe on the lower surface can be sucked and transported into the pipe so as to sweep away the sediment exposed on the open part. Is large on the tip side opposite to the suction side, whereby the sediment on the tip side is discharged so as to be greatly depressed.

  At this time, if the tube with the lower surface opened is a rigid body, only water will be sucked from the tip of the tube located in the large depression and the sand removal will not proceed, but the tube with the lower surface opened will have flexibility. If you keep it, the tip of the pipe sinks following the depression, and the surrounding earth and sand collapses toward the pipe and allows the sand removal to progress, thereby forming a conical depression The present invention has been completed by discovering that sand removal is possible.

  In other words, if you try to suck from the surface of the sediment that has accumulated in the pipe with the lower surface open, you must move the opening according to the sucked depression, and unless you move it, you can only suck and discharge sand in a very narrow area. However, in the present invention, by using a flexible pipe having a long bottom surface with a two-dimensional shape, it is possible to discharge sand conically in a three-dimensional range.

Based on such a viewpoint, the method for transporting bottom sediments according to claim 1 of the present invention provides an opening on a side surface of the sediment sediment surface when transporting sediment deposited on the bottom of a dam reservoir or the like. A flexible scavenging pipe provided is placed so as to close the opening, and the scavenging pipe and the surface of the sedimentary sediment surrounding it are covered with a sheet-like member . A suction pipe is connected to the base end portion to form a water flow from the tip end portion to the base end portion, and the sedimentary sediment facing the opening is sucked while being swept, and is formed around the tip end portion of the sweep pipe. It is characterized in that it is transported while being sucked until a conical depression is formed along the opening of the flexible scavenging pipe on the surface of the depression of the sediment.

According to this method of transporting bottom sediment, it is placed on sediment deposited so as to block the opening of a flexible sweep pipe having an opening on the bottom, and the sweep pipe and its surroundings are placed on the sediment. after the surface of the sediment was covered with a sheet-like member, to form a water flow to the proximal end from the distal end portion by connecting the suction tube to the proximal end of the sweep tube, facing the opening the Sedimentary sediment is sucked in while sweeping, and a conical recess is formed along the surface of the sedimentary sediment recess formed around the tip of the sweeper tube along the opening of the flexible sweeper tube. By transporting while sucking until it is formed, it is made to follow the depression of the deposited earth and sand formed around the tip of this scavenging tube by its flexibility, and by sinking of the tip and collapse of surrounding earth and sand in sweep tube 2 dimensional shape, ultimately formed a predetermined depth conical three-dimensional wide range of waste sand It has been cut way.

Also, methods of delivering the water bottom sediment of the invention, the water flow to be formed in the bed load pipe, a suction pump, siphon phenomenon state, and are not characterized by the form in either drop, sweep The water flow necessary for the flow suction can be secured.

Furthermore, the apparatus for transporting sediment deposited on the bottom according to claim 3 of the present invention is an apparatus for transporting sediment deposited on the bottom of a dam reservoir or the like, and has an opening on the side surface and closes the opening. A scavenging pipe having flexibility along the surface of a depression of the sedimentary earth and sand as it is placed on the sedimentary earth surface and facing the opening and facing the opening of the sedimentary earth and sand, and A sheet-like member provided so as to cover the surface of the sedimentary earth and sand, a suction pipe connected to a base end portion of the scavenging pipe, and the suction pipe and the front end portion of the scavenging pipe from the front end portion to the base end portion. It is characterized by comprising water flow forming means for forming a water flow for sweeping suction.

According to the apparatus for transporting bottom sediment, the sediment is placed on the sediment deposited so as to close the opening of a flexible sweep pipe having an opening at the bottom, and the sweep pipe and its surroundings are placed on the sediment. A sheet-like member that covers the surface of the sediment is provided, a suction pipe is connected to the base end of this scavenging pipe, a water flow is formed from the front end to the base end by water flow forming means, and the deposit faces the opening By sucking and transporting the earth and sand, it is made to follow the depression of the accumulated earth and sand formed around the tip of this sweep pipe with its flexibility, and by the large sinking of the tip and the collapse of the surrounding earth and sand With a two-dimensional shaped scavenging tube, a conical three-dimensional wide-area sand discharge of a predetermined depth can be finally achieved.

Also, the water bottom sediment transport apparatus according to the present invention comprises the flexible scavenging tube, a bellows tube having an opening at the bottom, a tube member having an opening at the bottom, and a bellows connecting them. A water flow generating means for forming a water flow in the tube member, a tube member provided with an opening on the bottom surface portion, and a connecting member for rotatably connecting these side portions, It is characterized by comprising either a suction pump, a siphon phenomenon, or a head. With these , the scavenging tube can be made flexible, and further, the water flow necessary for the scavenging suction can be secured. It becomes like this.

According to the method for transporting water bottom sediment of claim 1, wherein the present invention, placed on a sediment deposited so as to close the opening of the sweep tube flexible having an opening on the bottom, the sweep After covering the flow tube and the surface of the surrounding sediments with a sheet-like member, a suction tube is connected to the base end of the sweep tube to form a water flow from the tip to the base end. Since the sediment sediment facing the opening is sucked and transported, it is possible to follow the conical depression of the sediment sediment formed around the tip of this sweep pipe with its flexibility. By the sinking of the tip and the collapse of the surrounding earth and sand, a two-dimensional shaped scavenging tube can finally discharge a wide range of conical three-dimensional sand.

Further, according to the second aspect of the invention, it is possible to secure a water flow necessary for the scavenging suction .

Furthermore, according to the apparatus for transporting bottom sediment sediment according to claim 3 of the present invention, it is placed on the sediment deposited so as to close the opening of the flexible scavenging pipe having the opening at the bottom, A sheet-like member is provided to cover the sweep pipe and the surface of the surrounding sediment. The suction pipe is connected to the base end of the sweep pipe, and the water flow is generated from the front end to the base end by water flow forming means. Since the deposited sediment facing the opening is swept and transported by suction, it can follow the depression of the deposited sediment formed around the tip of this sweep pipe with its flexibility. With a simple structure of a two-dimensional shaped scavenging tube, a conical three-dimensional wide-area sand discharge can finally be performed.

According to the invention of claim 4, the sweeping tube can be made flexible, and according to the invention of claim 5, a water flow necessary for the sweeping suction can be secured.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
1 to 3 relate to one embodiment of the apparatus for transporting bottom sediment according to the present invention, FIG. 1 is a schematic plan view and a schematic cross-sectional view, and FIG. 2 is a schematic front view and a side view of a sweep pipe, respectively. FIG. 3 is a schematic configuration diagram of the water flow forming means.

  As shown in FIG. 3, for example, as shown in FIG. 3, this bottom sediment transport device 20 is installed in a reservoir 8 dammed by the dam 1, and is used as a sand discharge facility for discharging sediment sediment S to the downstream side of the dam 1. It is done.

  The bottom sediment transport apparatus 20 includes a sweep pipe 21 placed on the sediment S deposited on the natural ground at the bottom of the reservoir 8, as shown in FIG. The side portion (the side portion as a pipe and the bottom portion in the transported state of the sediment) is provided with the opening 22 and is configured to be flexible in the longitudinal direction. Has been.

  As shown in FIG. 2A, for example, as shown in FIG. 2A, the scavenging tube 21 having the opening portion 22 on the side surface portion and having flexibility is formed by cutting off a part of the side surface portion of the bellows tube 23. As shown in FIG. 2 (b), a short pipe member 24 having an opening 22 in a side surface portion thereof by groove-shaped steel, a bellows pipe member 25 having no cutout, and a bellows pipe material having a part cut away. 2 are alternately connected to each other, or, as shown in FIG. 2 (c), a short pipe member 24 having an opening 22 on the side surface portion by groove steel, and a connection portion 26 is provided and connected by a pin 27. Consists of.

  In each of these scavenging pipes 21, a connecting portion and a connecting portion 26 of the grooved steel pipe member 24 and the bellows pipe member 25 are provided so as not to suck water, earth and sand from other than the opening 22 and the tip opening 21 a. A seal member (not shown) is provided at the connecting portion between the tube members 24 when they are provided and connected by the pins 27 so that the sealed state can be maintained even when the sweep tube 21 is bent.

  Note that the cross-sectional shape of the scavenging pipe 21 and the size and shape of the opening 22 are closed with the sediment 22 with the opening 22 down when placed on the surface of the sediment from a pump ship or the like on the surface of the reservoir. However, it is not limited to the illustrated example and may be determined as appropriate.

The scavenging pipe 21 is used by placing the opening 22 on the side surface thereof on the earth and sand S deposited in the reservoir 8 so that the opening 22 is closed as a bottom surface, and the earth and sand S is sucked. The surface of the sediment S that changes depending on the situation, that is, it is possible to follow along the depression, and finally, it has flexibility to follow along the conical depression.

  A water flow forming means 29 for forming a water flow from the front end opening 21a toward the base end 21b in the sweep pipe 21 (and the suction pipe 28) via the suction pipe 28 is provided at the base end 21b of the sweep pipe 21. It is connected.

  As this water flow formation means 29, for example, as shown in FIG. 3 (a), the sand discharge constructed by the pump 30a of the pump ship 30 on the water surface of the reservoir 8 and piped over the upper end of the dam dam body. Sand can be discharged to the downstream side of the dam through the pipe 31, or, as shown in FIG. 3B, it can be configured by the siphon 32 and connected to the sand discharge pipe 31 to discharge the sand to the downstream side of the dam. As shown in FIG. 3 (c), a water flow is formed by using a water level difference (fall) formed by a through sand discharge pipe 33 penetrating the dam dam body 1, and the dam is formed through the through sand discharge pipe 33. The sand should be discharged downstream.

  The penetrating sand discharge pipe 33 penetrating the dam dam body 1 may be at an altitude higher than the sedimentation surface of the sediment S and forms a water flow in the sweep pipe 21 from the tip opening 21a toward the base end portion 21b. I can do it.

  Further, in the water bottom sediment transport apparatus 20, a sheet-like member 34 is provided so as to cover the surface of the sedimentary sediment S around the surface of the sedimentary sediment S placed on the surface of the sediment sediment S. While improving the followability to the hollow surface of the sediment earth and sand S which collapses and deform | transforms by this suction | attraction, it is made not to attract only water.

Next, the operation of the water bottom sediment transport apparatus 20 configured as described above and the transport method will be described with reference to the sand removal process diagram shown in FIG.
First, the suction pipe 28 is connected to the base end part 21b of the flexible scavenging pipe 21 having the opening 22 on the side surface, and the scavenging pipe 21 is placed on the surface of the sediment S from the work ship of the reservoir 8. The opening 22 is placed below, and the opening 22 is placed so as to be covered with the sediment S.
At this time, the tip opening 21a of the scavenging tube 21 is positioned at the center of the place where sand removal is to be performed (the center of the conical depression finally formed ) (see FIG. 4A).

  Then, for example, a pump 30a of a pump ship 30 is connected to the suction pipe 28 as the water flow forming means 29 so that a water flow is formed from the distal end opening 21a of the sweep pipe 21 toward the base end portion 21b.

  Furthermore, a sheet-like member 34 is laid so as to cover the scavenging pipe 21 and the surrounding sediment S as necessary.

  After that, the pump 30a of the pump ship 30 is operated to generate a suction force in the suction pipe 28, and water in the reservoir 8 is sucked from the distal end opening 21a of the sweep pipe 21 to form a water flow toward the base end 21b.

  When the suction pipe 28 starts to suck water, the water flowing through the sweep pipe 21 sweeps the sediment S and sand exposed at the opening 22 (referred to as sweeping away by the flow) and sends it to the suction pipe 28.

  Since the scavenging force generated in the scavenging tube 21 is larger in the tip opening 21a of the scavenging tube 21, the amount of sediment sediment S in the tip opening 21a is larger, and the depression surrounds the scavenging tube 21. The sedimentary sediment S collapses, and the tip opening 21a of the flexible scavenging pipe 21 sinks along the surface of the depression first, so that the sedimentary sediment S is continuously sucked and transported (see FIG. 4 (b)).

In this way, by forming a water flow in the sweep pipe 21 through the suction pipe 28 and continuing the suction, the sedimentary sediment S is swept while forming a conical depression centering on the tip opening 21a of the sweep pipe 21. It can be poured and transported by suction, and sand is discharged until a conical depression having a predetermined depth is finally formed (see FIG. 4C).

  Furthermore, when carrying out suction transport of the sediment earth and sand S, the sweep pipe 21 is moved, the opening part 22 is again placed so as to be closed with the sediment earth and sand S, and the same process is repeated.

According to such a method and apparatus 20 for transporting bottom sediment, the sediment S is finally spread over a three-dimensional range of conical depressions using a two-dimensional apparatus using a sweep pipe 21 and a suction pipe 28. It can be transported by suction and is limited to the vicinity of the pipe where the pipe is buried in advance or the sand discharge area is fixed, as in the case of sand removal with a pipe with an opening buried in advance in the reservoir bottom of Patent Document 1. The sedimentary sediment S can be sucked and transported over a wide range simply by placing the sweep pipe 21 at an arbitrary location.

In addition, it has been confirmed by model experiments that the sediment can be sucked and transported while finally forming a conical depression by the sweep pipe and the suction pipe.

  In addition, a large sheet-like member having a diameter of 100 m or the like as in the case where a sheet-like member is laid on the surface of the accumulated earth and sand according to Patent Document 2 and discharged is moved, or the laying position is moved. In addition, according to the method and apparatus 20 for transporting sediment deposited on the bottom of the bottom, suction and transport of sediment sediment S over a wide range in which the length of the sweep pipe 21 is the length of the conical generatrix is performed by the sweep pipe 21 and the suction pipe 28. be able to.

  Furthermore, according to this method and apparatus 20 for transporting sediment deposited sediment, when using a siphon 32 as the water flow forming means 29 or when using a water level drop by the penetrating sand discharge pipe 31, it is necessary for suction sand discharge. Suction sand removal is possible without the need for energy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view and a schematic cross-sectional view according to an embodiment of a water bottom sediment transport apparatus of the present invention. It is the schematic front view and side view of each sweep pipe concerning one embodiment of the transportation device of the bottom sediment sediment of this invention. It is a schematic block diagram of each water flow formation means concerning one Embodiment of the transportation apparatus of the bottom sediment sediment of this invention. It is explanatory drawing of the sand removal process concerning one Embodiment of the transportation method of the bottom sediment sediment 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 and a partially enlarged view of a conventional underwater sediment flow facility. It is a schematic block diagram of the conventional sand removal apparatus of a reservoir.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dam dam body 8 Reservoir 20 Submarine sediment transport equipment 21 Swivel pipe 21a Tip opening 21b Base end part 22 Opening part 23 Bellows pipe (sweeping pipe)
24 short pipe member 25 bellows pipe member 26 connecting portion 27 pin 28 suction pipe 29 water flow forming means 30 pump ship 30a pump 31 sand discharge pipe 32 siphon 33 penetrating sand discharge pipe 34 sheet-like member S sediment

Claims (5)

When transporting sediment deposited on the bottom of dam reservoirs,
On the surface of the sedimentary earth and sand, a flexible sweep pipe having an opening on the side surface portion is placed so as to close the opening, and the surface of the sedimentary earth and sand around the sweep pipe is surrounded by a sheet. After covering with a member, a suction pipe is connected to the base end of the scavenging pipe to form a water flow from the tip to the base end, and sucking the sediment while facing the opening. Then, transport while sucking until the conical depression is formed along the opening of the flexible scavenging pipe along the surface of the depression of the sediment sediment formed around the tip of the sweep pipe A method for transporting bottom sediments characterized by that. 2. The method of transporting bottom sediment according to claim 1, wherein the water flow formed in the sweep pipe is formed by any one of a suction pump, a siphon phenomenon, and a drop. A device that transports sediment deposited on the bottom of a dam reservoir, etc.
Flexibility along the surface of the depression of the sedimentary sediment with the side surface having an opening and being placed on the sedimentary sediment surface so as to close the opening, along with the suction suction of the sedimentary sediment facing the opening A sweep tube having
A sheet-like member provided so as to cover the sweep pipe and the surface of the surrounding sediments;
A suction pipe coupled to the proximal end of the sweep tube,
An apparatus for transporting bottom sediments comprising the suction pipe and water flow forming means for forming a water flow for sweep suction from the distal end portion to the proximal end portion of the sweep pipe. The flexible scavenging tube includes a bellows tube having an opening on a side surface, a tube member having an opening on a side surface, a bellows tube member connecting them, and a tube member having an opening on a side surface. 4. The apparatus for transporting bottom sediment according to claim 3 , further comprising a connecting member that rotatably connects these side portions. 5. 5. The water bottom sediment transport apparatus according to claim 3, wherein the water flow generating means for forming a water flow in the sweep pipe is constituted by any one of a suction pump, a siphon phenomenon, and a drop.

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