JP2013019112A - Suction conveyance device for underwater sediment and suction conveyance method for underwater sediment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suction conveyance device for underwater sediment and a suction conveyance method for underwater sediment which can suck and remove the sediment efficiently and economically by increasing the layer thickness of the sediment that can be sucked.SOLUTION: A suction conveyance device A for underwater sediment comprises an outer pipe 2 in which a plurality of suction ports 1 are penetrated in the peripheral surface at intervals in the direction of axis line O1 while a water taking-in port 6 for taking in water W inside is formed and which is erected so that the direction of axis line O1 is directed in a vertical direction, the water taking-in port 6 is arranged in the water W and that the suction ports 1 are arranged in a sediment S, an inner pipe 4 in which a plurality of introduction ports 3 are penetrated in the peripheral surface at intervals in the direction of axis line O2 and which is inserted in the outer pipe 2 with a gap H placed with the outer pipe 2, an opening/closing device 10 which opens/closes the introduction port 3 and a discharge pipe 5 which is disposed so that one end is connected to the upper end of the inner pipe 4.

Description

  The present invention relates to an underwater sediment suction transport device and an underwater sediment suction transport method for suctioning and removing sediments such as earth and sand deposited on the bottom of a dam reservoir or the like.

  In dam reservoirs where rivers have been dammed for the purpose of flood control and water use, sediment such as sediment transported from the upstream area of the river accumulates at the bottom of the water, reducing the effective water storage volume, resulting in flood damage and water use capacity. It causes a decrease, and the supply of earth and sand to the downstream area decreases, resulting in river bed degradation, coarsening, coastal erosion (sand beach thinning), and the like. For this reason, it is necessary to remove the sediment accumulated on the bottom of the water periodically or as necessary. Not only in dam reservoirs, but also in water storage facilities such as sewage treatment plants and reservoirs, and in closed water areas such as seas, rivers, lakes, ponds, and canals, sediment collected at the bottom of the water regularly or as needed There are many cases where it is necessary to remove.

  And as a method for conveying and removing this kind of deposit, a suction type sand removal method such as a hydropipe method or a multi-hole suction method (MHS method) has been proposed and put into practical use (for example, Patent Document 1, Patent Document) 2).

  In the suction-type sand removal method, a suction pipe (discharge pipe) formed by penetrating a circular or slit-shaped suction port on the peripheral surface is laid on the sediment of a dam reservoir, for example. Lay it on the bottom of the groove. Also, the suction pipe has one end on the upstream side arranged in the water above the deposit, and the other end on the downstream side is arranged at least below the water surface (preferably below the opening end on the upstream side). It is laid like that. In some cases, the suction pipe is previously laid on the bottom of the dam when the dam is newly constructed.

  Then, due to the difference in water level between the upstream end and the downstream other end, when water is sucked from the upstream end and flows through the suction pipe laid sideways, a negative pressure is generated in the suction pipe. Surrounding deposits are sequentially sucked from the suction port by this negative pressure. As a result, sediment is discharged together with water from the other end downstream of the suction pipe, using the movement of water due to the difference in water level (using the siphon principle), without requiring special energy, such as earth and sand. It is possible to remove the deposits by suction conveyance.

Japanese Patent No. 3893479 Japanese Patent No. 4663145

  On the other hand, in the conventional suction-type sand discharge method, the suction pipe laid on the deposit removes the deposit by sequentially sucking it from the suction port, and is buried in the deposit with one end arranged in water. Go. Also, the suction pipe laid at the bottom of the groove deposits deposits on it, sucks the deposits sequentially from the suction port, and is buried in the deposit with one end arranged in the water. go. And when laying down sideways in this way and removing the deposit by suction with the suction pipe embedded in the deposit, the negative pressure of the suction port causes the water in the deposit above the suction pipe to The suction force acts, and the deposits are sucked and removed while breaking the piping.

  For this reason, in the conventional suction type sand removal method, if the layer thickness of the deposit (excluding consolidated and solidified silt and clay) on the buried suction pipe is about several meters, it is removed by suction with the suction pipe. However, when the layer thickness reaches 10 m, the permeate flow length from the surface layer of the deposit to the suction port becomes too large, and the deposit around the suction tube is consolidated. As a result, it is difficult to cause the deposits to be destroyed by piping, and there is a problem in that the deposits are successively broken down and cannot be removed by suction.

  Further, in the above conventional suction type sand discharge method, the suction pipe is laid horizontally on or in the deposit, and the suction port faces in the vertical direction, so the suction port is likely to be blocked by foreign matters such as dust. Furthermore, since the suction pipe is buried in the sideways state, there is a problem that maintenance is difficult (or maintenance cannot be performed). In addition, when a suction pipe is laid by excavating and forming a groove, the greater the layer thickness for which the removal of deposits is planned, the more labor and cost are required to form the groove.

  In view of the above circumstances, the present invention provides an underwater deposit suction conveyance device and an underwater deposit that can efficiently and economically remove the deposit by increasing the layer thickness of the deposit that can be sucked. It is an object to provide a suction conveyance method.

  In order to achieve the above object, the present invention provides the following means.

  The underwater deposit suction conveyance device of the present invention is an underwater sediment suction conveyance device for removing the sediment accumulated on the bottom of the water by suction conveyance, wherein a plurality of suction ports are spaced apart in the axial direction on the peripheral surface. And is formed with a water intake port for taking water inside, with the axial direction facing up and down, the water intake port arranged in water, and the suction port A plurality of inlets are formed in the peripheral surface at intervals in the axial direction, and an outer tube is provided standing in the deposit, and a gap is formed between the outer tube and the outer tube. An inner pipe inserted and installed inside, an opening / closing device that opens and closes the introduction port, and a discharge pipe that is arranged with one end connected to the upper end of the inner pipe. And

  Further, in the underwater deposit suction conveyance device of the present invention, the deposit that protrudes from the outer surface of the inner tube toward the inner surface of the outer tube and that enters the gap from the suction port of the outer tube is received. It is desirable to provide a deposit fall prevention means for preventing the deposit from falling to the lower part of the gap.

  The underwater deposit suction and transport method according to the present invention is a suction and transport method of underwater sediment by sucking and transporting deposits accumulated on the bottom of the water, wherein a plurality of suction ports are spaced apart in the axial direction on the peripheral surface. The outer pipe formed with a water intake port for taking water inside is oriented in the vertical direction, the water intake port is arranged in water, and the suction is made A mouth is arranged in the deposit, and an inner pipe in which a plurality of inlets are formed in the peripheral surface so as to be openable and closable with an interval in the axial direction is provided with a gap between the outer pipe and the outer pipe. The inside of the outer pipe is inserted and installed, one end is connected to the upper end of the inner pipe, a discharge pipe is disposed, an arbitrary inlet is opened by an opening / closing device, and the one end is placed in the discharge pipe Water from the water intake port to the other end, and through the gap through the water intake port. A flow of water that sequentially flows from the inside of the inner pipe to the discharge pipe is formed through the introduced inlet, and the deposit is sucked into the gap from the suction port by a negative pressure generated in the gap by the flow of water. The water is discharged from the other end of the discharge pipe together with water.

  In the method for sucking and conveying underwater deposits of the present invention, the plurality of inlets are opened stepwise from the upper inlet in the axial direction to the lower inlet in the order of the inner pipe, and the deposits are surfaced. It is desirable to perform suction removal step by step from the side.

  Here, the deposit according to the present invention means a substance accumulated in the bottom of the water, and includes a precipitate, a sediment and the like.

  In the underwater deposit suction and conveyance device and the underwater deposit suction and conveyance method of the present invention, when water is circulated in the discharge pipe so as to be discharged from the other end, the outer pipe and the inner pipe are connected from the water intake port of the outer pipe. Water enters the gap between the pipes, and the water continuously flows through the gap and enters the inside of the inner pipe from the introduction port, and then flows through the inside of the discharge pipe from the inner pipe and is discharged. Further, at this time, negative pressure is generated in the gap between the outer tube and the inner tube due to the circulation of water, and deposits can be sucked into the gap from the suction port of the outer tube by this negative pressure. It becomes possible to convey and remove the sediment together with water from the inner pipe and the inner pipe through the discharge pipe. In addition, if the other end of the discharge pipe is disposed at least below the water surface, water can be automatically circulated inside the discharge pipe, the gap, and the inner pipe by the siphon principle. It is possible to remove the deposit by suction and conveyance without requiring energy.

  In addition, since the outer tube and the inner tube are erected with the axial direction facing the vertical direction, there is no need to excavate and form grooves in the deposit, for example. Furthermore, when an arbitrary inlet port of the inner pipe is opened by the opening / closing device, the deposit can be crushed into a mortar shape around the suction port of the outer pipe corresponding to the inlet port and removed by suction.

  In this way, the lower inlet is opened in stages from the upper inlet in order, and the deposits are suctioned and removed stepwise by the suction ports corresponding to the inlets of each stage, so that deposition is performed as in the past. Even when the thickness of the deposit reaches several tens of meters, the permeation flow length from the surface of the material to the suction port becomes too large, making it difficult to cause piping failure. As a result, the deposit can be removed by suction and transportation economically.

  Furthermore, since the outer pipe and the inner pipe are erected, the suction port (or inner pipe) of the outer pipe is compared with the case where the conventional suction pipe (discharge pipe) is installed on the deposit or in the deposit. Is difficult to block by foreign matter. In addition, since the outer pipe and the inner pipe are erected and are not embedded in the sediment as in the conventional case, the inner pipe can be pulled out from the outer pipe and separated and recovered, thereby improving maintenance. Is possible.

It is a figure which shows the suction conveyance apparatus of the underwater deposit which concerns on one Embodiment of this invention. It is an enlarged view which shows the suction conveyance apparatus of the underwater deposit which concerns on one Embodiment of this invention. It is a figure which shows the opening / closing apparatus of the suction conveyance apparatus of the underwater deposit which concerns on one Embodiment of this invention, and a deposit fall prevention means. It is a figure which shows the state which open | released the inlet of the 1st step (uppermost step) and sucked and removed the deposit in the suction conveyance method of the underwater deposit which concerns on one Embodiment of this invention. In the suction conveyance method of underwater sediment concerning one embodiment of the present invention, it is a figure showing the state where the 2nd (middle stage) inlet was opened and the sediment was sucked and removed. It is a figure which shows the state which open | released the 3rd stage (lowermost stage) inlet and sucked and removed the deposit in the underwater deposit suction conveyance method which concerns on one Embodiment of this invention. In the suction conveyance method of underwater sediment concerning one embodiment of the present invention, it is a figure showing the state where the inlet is opened and the sediment is sucked and removed. It is a figure which shows the modification of the suction conveyance apparatus of the underwater deposit which concerns on one Embodiment of this invention. It is a figure which shows the modification (modification of a deposit fall prevention means) of the suction conveyance apparatus of the underwater deposit which concerns on one Embodiment of this invention.

  Hereinafter, an underwater deposit suction transport apparatus and an underwater deposit suction transport method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. The present embodiment relates to an underwater deposit suction transfer device and an underwater deposit suction transfer method for sucking and removing deposits such as earth and sand accumulated on the bottom of a dam reservoir or the like.

  As shown in FIGS. 1 and 2, the underwater deposit suction conveyance device A of the present embodiment has a cylindrical outer tube 2 having a plurality of suction ports 1 formed through the peripheral surface, and a plurality of suction ports 1 on the peripheral surface. A cylindrical inner pipe 4 through which the introduction port 3 is formed is provided, and a discharge pipe 5 is provided with one end 5 a connected to the upper end 4 a of the inner pipe 4.

  The outer tube 2 is, for example, a steel tube, and a plurality of suction ports 1 are arranged at predetermined intervals in the direction of the axis O1 (center axis direction). Further, in the present embodiment, the plurality of suction ports 1 are arranged by shifting the positions of the suction ports 1 adjacent in the vertical direction in the direction of the axis O1 in the circumferential direction around the center of the axis O1. Furthermore, in the present embodiment, the upper end 2 a and the lower end 2 b of the outer tube 2 are opened, and the opening of the upper end 2 a is the water intake port 6. In the present embodiment, the suction port 1 is formed as a circular hole, an elliptical hole, or the like, but it is not necessary to limit the shape thereof. In addition, the plurality of suction ports 1 do not necessarily have to be disposed by shifting the positions of the suction ports 1 adjacent to each other in the circumferential direction, and may be disposed on the same line in the vertical direction. However, considering the strength of the outer tube 2, the installation of the opening / closing device 10 described later, and the ability to uniformly suck the deposit S from each of the plurality of suction ports 1 (uniform suction), FIG. It is preferable to arrange a plurality of suction ports 1 in a staggered manner as shown in FIG.

  The outer tube 2 configured as described above is erected with the direction of the axis O1 in the vertical direction, the water intake port 6 disposed in the water W, and the plurality of suction ports 1 disposed in the sediment S. Established. Further, the outer tube 2 of the present embodiment penetrates the lower end 2b side of the outer tube 2 further below the suction removal range R set in advance from the surface S1 of the deposit S, and secures the necessary penetration length T. It is erected in support and is permanently installed in the water area.

  Note that the outer tube 2 may be erected by supporting it with a separately provided support column, instead of erected with the necessary penetration length T secured. That is, the outer tube 2 can be erected with the axis O1 direction in the vertical direction, the water intake port 6 disposed in the water W, and the plurality of suction ports 1 disposed in the sediment S. If so, it is not necessary to limit the means and method. Further, the outer pipe 2 may not be permanently installed in the water area, but may be erected while being supported so as to be appropriately movable.

  The inner pipe 4 is a steel pipe, for example, and is formed with an outer diameter smaller than the inner diameter of the outer pipe 2. The inner tube 4 is formed so as not to determine the position of the introduction port 3 alone but to correspond to the position of the suction port 1 of the outer tube 2. In the present embodiment, a plurality of inlets 3 are arranged at predetermined intervals in the direction of the axis O2 (center axis direction) of the inner tube 4 so as to correspond to the position of the suction port 1 of the outer tube 2. In addition, the positions of the inlets 3 adjacent in the vertical direction in the direction of the axis O2 are shifted in the circumferential direction about the center of the axis O2. In the present embodiment, the introduction port 3 is formed as a circular hole, an elliptical hole, or the like. However, like the suction port 1, it is not necessary to limit the shape thereof.

  As shown in FIGS. 2 and 3, the inner tube 4 is provided with an opening / closing device 10 for opening and closing each inlet 3 individually. The opening / closing device 10 supports the opening / closing plate 11 having a circular arc shape, which is curved with a curvature substantially equal to the curvature of the peripheral surface of the inner tube 4, and the opening / closing plate 11 in a state of being overlapped with the inner tube 4. And a drive mechanism 12 for moving back and forth in the direction of the axis O2. Further, the drive mechanism 12 has, for example, one end connected to the opening / closing plate 11 and a forward / backward rod 13 provided with a central axis thereof arranged in the direction of the axis O2 of the inner tube 4, and the forward / backward rod 13 and the axis O2 And a drive unit 14 that moves forward and backward in the direction. As shown in FIG. 3A, when the drive unit 14 is driven, the advance / retreat rod 13 is retracted in one direction along the axis O2 and the open / close plate 11 is retracted in one direction, whereby the inlet 3 of the inner tube 4 is restored. Is released. Further, as shown in FIG. 3B, when the advance / retreat rod 13 is advanced in the other direction of the axis O2 and the opening / closing plate 11 is advanced in the other direction, the opening / closing plate 11 overlaps with the introduction port 3 of the inner tube 4. As a result, the inlet 3 is closed.

  As shown in FIGS. 1 and 2, the inner tube 4 is inserted and installed in the outer tube 2 with a gap H between the outer surface 4 c and the inner surface 2 c of the outer tube 2. At this time, for example, the pair of introduction ports 3 of the inner tube 4 and the suction port 1 of the outer tube 2 and the suction port 1 are arranged to face each other, that is, the pair of introduction ports 3 and the suction port 1 are predetermined. The inner tube 4 is inserted and installed inside the outer tube 2 so as to be disposed at a relative position.

  Further, as shown in FIG. 2, the inner tube 4 of the present embodiment has a roller member (rubber roller) 16 connected to and supported by a shaft portion 15 projecting outward from the outer surface 4c in the direction of the axis O2. A plurality are provided at predetermined intervals. Thus, when the inner tube 4 is inserted into the outer tube 2 for installation or when the inner tube 4 is pulled out from the outer tube 2, the inner tube 4 is smoothly guided by the roller member 16, and the insertion is performed. Can be easily pulled out. Further, when the inner tube 4 is inserted into the outer tube 2, the roller member 16 is interposed between the inner surface 2 c of the outer tube 2, so that a predetermined size is surely provided between the outer tube 2 and the inner tube 4. The gap H is formed.

  Further, as shown in FIGS. 2 and 3, in the inner tube 4, the deposit S that has entered the gap H between the outer tube 2 and the inner tube 4 from the suction port 1 of the outer tube 2 falls to the lower part of the gap H. The deposit fall prevention means 20 for preventing this is provided. And the deposit fall prevention means 20 of this embodiment is provided for each pair of the inlets 3 and the suction ports 1, and is located outside the outer surface 4 c of the inner tube 4 at a position slightly below the inlets 3. The bottom plate 21 protrudes toward the inner surface 2c of the tube 2 and extends in the circumferential direction around the axis O2 of the inner tube 4. The bottom plate protrudes from the outer surface 4c of the inner tube 4 toward the inner surface 2c of the outer tube 2. The lower end is connected to one end and the other end in the circumferential direction of the portion 21, and a pair of side plate portions 22, 23 extending upward along the direction of the axis O 2 is configured. Further, the bottom plate portion 21 is formed with a width that is larger than the width in the circumferential direction of the introduction port 3 and the suction port 1. The pair of side plate portions 22 and 23 are formed with a length dimension larger than the length of the introduction port 3 and the suction port 1 in the axis O2 direction, and between the pair of side plate portions 22 and 23 in the circumferential direction. And the suction port 1 is formed. Further, the bottom plate portion 21 and the side plate portions 22, 23 have a protruding dimension that protrudes radially outward from the outer surface 4 c of the inner tube 4 toward the inner surface 2 c of the outer tube 2, and the gap H between the outer tube 2 and the inner tube 4. It is formed with a dimension slightly smaller than the thickness dimension.

 Thus, when the inner tube 4 is inserted and installed at a predetermined position inside the outer tube 2, the gap H between the pair of introduction ports 3 and the suction port 1 has a bottom plate portion 21 on the lower side and a pair of side plate portions on both sides. It will be in the state surrounded by 22 and 23. The deposit fall prevention means 20 surrounds the bottom plate portion 21, the pair of side plate portions 22, 23, the inner surface 2 c of the outer tube 2, and the outer surface 4 c of the inner tube 4, and is opened by the opening / closing device 10. It is possible to form a space P in which the suction ports 1 are opened and communicated with each other.

  On the other hand, the discharge pipe 5 is a flexible pipe material. As shown in FIGS. 1 and 2, the one end portion 5 a is connected to the upper end portion 4 a of the inner tube 4 and is arranged in communication with the inner tube 4. Is done. Moreover, in this embodiment, this discharge pipe 5 connects the other end part 5b to the sand pipe provided in the dam body 24, and this other end part 5b is connected to the water surface W1 such as a dam reservoir. It is arranged below. Further, the discharge pipe 5 is connected to the float 25 and is disposed with the portion between the one end 5a and the other end 5b floating in the water W. It should be noted that the discharge pipe 5 has no particular problem even if the portion between the one end portion 5a and the other end portion 5b is placed on the deposit S.

  Next, a method for conveying and removing the deposit S using the underwater deposit suction conveyance device A of the present embodiment having the above-described configuration will be described, and the underwater deposit suction conveyance device A and the underwater deposition of the present embodiment will be described. The operation and effect of the method for sucking and conveying an object will be described.

  As shown in FIGS. 1 and 2, when removing sediment S such as earth and sand accumulated on the bottom of the water, first, the axis O1 direction is directed vertically and the water intake 6 is disposed in the water W. A plurality of suction ports 1 are arranged in the deposit S, and the outer tube 2 is installed.

At this time, for example, the outer pipe 2 can be installed by applying the medium excavation method frequently used in the construction method of steel pipe piles. Specifically, a spiral auger screw is inserted into the outer pipe 2 and the outer pipe 2 is set in a driving device of a pile driving machine such as being placed on a carriage. Next, the auger screw and the outer tube 2 are lowered to the bottom of the water by the driving device, and the auger screw is rotated to excavate the deposit S. Further, the outer pipe 2 is penetrated into the deposit S by its own weight or by pressurization by a press-fitting device while discharging the deposit S excavated through the inside of the outer pipe 2. Then, the lower end 2b side of the outer tube 2 is penetrated below the suction removal range R set in advance from the surface S1 of the deposit S to ensure a predetermined penetration length T, and the water intake 6 is water. The outer pipe 2 is erected in a state in which the plurality of suction ports 1 are arranged in the deposit S in the deposit S. Thereby, the outer tube 2 can be erected while discharging sediment S such as earth and sand from the inside of the outer tube 2.
In addition, when the lower end 2b side of the outer tube 2 is penetrated with a predetermined penetration length T, the auger screw is pulled up while spraying root solid liquid such as cement milk, and the lower end 2b side of the outer tube 2 is consolidated. May be. In this case, the outer tube 2 can be erected in a more stable state. In addition, a bottom base concrete 26 is placed in the inner part of the outer pipe 2 and measures are taken to prevent the ground (sediment S) on the lower end 2b side of the outer pipe 2 from being eroded by the flow of water W. It is preferable to keep it.

  Next, after installing the outer tube 2, the inner tube 4 is inserted and installed inside the outer tube 2. At this time, for example, one end 5a of the discharge pipe 5 is connected to the upper end 4a of the inner pipe 4 in advance, and the inner pipe 4 is inserted into the outer pipe 2 with all the inlets 3 closed by the opening / closing device 10. I will do it. Then, when the other end 5b side of the discharge pipe 5 is opened by opening the valve of the sand discharge pipe connected to the other end 5b of the discharge pipe 5, the outer pipe 2 is automatically set by the water pressure (water level difference). Water W flows into the gap H between the outer tube 2 and the inner tube 4 from the water intake 6 that opens to the upper end 2a of the tube. Then, the water W flowing downward through the gap H flows into the inner tube 4 from the opening 4d at the lower end 4b of the inner tube 4, flows through the inner tube 4 upward and flows through the discharge tube 5. A flow of water W discharged outside from the other end portion 5b of the discharge pipe 5 is formed.

  Thus, even when the inner pipe 4 is installed, even if the deposit S enters the inside from the suction port 1 of the outer pipe 2 and the deposit S accumulates in the lower part inside the outer pipe 2. While the inner pipe 4 is inserted into the outer pipe 2, the deposit S accumulated in the lower part due to the flow of the water W is sucked from the opening 4 d of the lower end 4 b of the inner pipe 4 and removed from the discharge pipe 5 to the outside. Can do. Therefore, even if the deposit S is accumulated inside the outer tube 2, the inner tube 4 is securely placed at a predetermined position inside the outer tube 2 while sucking and removing the deposit S as shown in FIGS. 1 and 2. Insertion can be installed.

  At this time, since the roller member 16 is provided in the inner tube 4, the inner tube 4 is smoothly guided by the roller member 16 when the inner tube 4 is inserted and installed in the outer tube 2. , Easy insertion work. Further, when the inner tube 4 is inserted into the outer tube 2, the roller member 16 is interposed between the inner surface 2 c of the outer tube 2, so that a predetermined size is ensured between the outer tube 2 and the inner tube 4. The gap H is formed.

  Further, when the inner tube 4 is inserted and installed at a predetermined position inside the outer tube 2, the gap H between the pair of introduction ports 3 and the suction ports 1 at each stage is lower as shown in FIGS. Both sides are surrounded by a pair of side plate portions 22 and 23 by the bottom plate portion 21 of the deposit fall prevention means 20. As a result, a space P where the introduction port 3 and the suction port 1 opened by the opening / closing device 10 are opened and communicated with each other is formed in the gap H by the deposit fall prevention means 20.

  Next, in this embodiment, as shown in FIGS. 4 to 6, the inner pipe 4 is opened in stages from the upper inlet 3 in the direction of the axis O <b> 2 to the lower inlet 3. 4, 5, and 6 illustrate a state in which the inlet 3 of each stage is opened and the deposit S is completely removed by suction from the inlet 1 of each stage.

  Specifically, in the method for sucking and conveying underwater deposits of the present embodiment, first, as shown in FIGS. 4 and 7, the inlet 3 located at the uppermost stage (first stage) of the inner tube 4 is set to the inlet. The opening / closing device 10 that opens and closes 3 is driven to open. Then, the water W that enters the gap H from the water intake 6 at the upper end 2 a of the outer pipe 2 and flows downward through the gap H flows into the inner pipe 4 from the uppermost inlet 3, and from the inner pipe 4. A flow of water W discharged outside through the discharge pipe 5 is formed.

  When such a flow of water W is formed and the water W flows through the gap H, a negative pressure is generated. As shown in FIGS. 4 and 7, the uppermost inlet 3 and the pair of uppermost suction ports The deposit S is sucked into the gap H from 1, transported with the water W through the inner pipe 4 and the discharge pipe 5, and discharged to the outside. In addition, the water W continuously flows through the gap H between the outer tube 2 and the inner tube 4, so that the external deposit S is an angle corresponding to the repose angle θ of the deposit S around the uppermost suction port 1. While collapsing into a mortar shape, external deposits S are sequentially sucked and removed from the uppermost suction port 1.

 Further, at this time, the gap H between the pair of introduction ports 3 and the suction port 1 at each stage is surrounded by the bottom plate portion 21 and the pair of side plate portions 22 and 23 of the deposit fall prevention means 20. (See FIG. 3) The deposit S sucked from the suction port 1 is received by the bottom plate portion 21 and dammed up by the bottom plate portion 21 and the pair of side plate portions 22, 23. It is prevented that it falls into the lower part of the gap H without entering the inside. This prevents inconveniences such as the gap H being clogged with the deposit S, and the deposit S is suctioned and removed reliably and efficiently.

  Then, when the deposit S is removed in the shape of a mortar and the uppermost suction port 1 is exposed in the water W, not the deposit S but the water W is sucked from the uppermost suction port 1, and the uppermost inlet 3. Are discharged to the outside through the inner pipe 4 and the discharge pipe 5. For this reason, as shown in FIG. 4, the amount of the deposit S that is removed by suction from the uppermost suction port 1 is reduced at the stage where the deposit S cannot be sucked by the uppermost suction port 1. At the stage, as shown in FIG. 5, the opening / closing device 10 is driven to close the uppermost introduction port 3, and the second (middle) introduction port 3 positioned one step below the uppermost introduction port 3. Is released. Then, as shown in FIGS. 5 and 7, the water W entering the gap H from the water intake port 6 and the first suction port 1 of the upper end 2 a of the outer pipe 2 and flowing downward through the gap H is in two stages. A flow of water W that flows into the inner tube 4 from the eye inlet 3 and is discharged to the outside through the discharge tube 5 from the inner tube 4 is formed.

  When such a flow of water W is formed, as shown in FIGS. 5 and 7, the deposit S is sucked into the gap H from the uppermost inlet 3 and the pair of uppermost suction ports 1. As described above, the deposit S starts to be sucked from the second suction port 1 by the negative pressure generated in the gap H, and is transported by the inner pipe 4 and the discharge pipe 5 together with the water W and discharged to the outside. Similarly to the state in which the deposit S is sucked from the uppermost suction port 1, the water W continuously flows through the gap H between the outer tube 2 and the inner tube 4, so that the outer deposit S becomes the second step. The external deposit S is sequentially sucked and removed from the second-stage suction port 1 while collapsing into a mortar shape with an angle corresponding to the angle of repose θ of the deposit S around the suction port 1.

  Also, as shown in FIGS. 6 and 7, the lowermost inlet 3 is opened, and a flow of water W is formed in the same manner as described above, and the deposit S is sucked and removed while collapsing into a mortar shape. Then, as shown in FIGS. 4 to 7, the inlet 3 from the top to the bottom is sequentially opened and closed, and the deposit S is sucked and removed while collapsing from the suction port 1 of each stage into a mortar shape. That is, the plurality of introduction ports 3 are sequentially opened and closed in order from the upper introduction port 3 in the direction of the axis O2 of the inner tube 4 to the lower introduction port 3, and the deposit S is suctioned and removed stepwise from the surface layer S1 side. As a result, the permeation flow length of the deposit S from the surface layer S1 to the suction port 1 does not become too large as in the prior art, and even if the deposit S is compacted to some extent, piping failure occurs and the surface layer S1 side It is surely removed by sucking in order.

  4, 5, and 6, the deposit S is illustrated so as to be sucked and removed in a mortar shape around the axes O <b> 1 and O <b> 2 of the outer tube 2 and the inner tube 4. Then, the deposit S is sucked and removed in a mortar shape around the suction port 1 of each stage.

Also, as shown in Tables 1 and 2, for example, when the sediment S such as earth and sand having an angle of repose θ of 30 degrees is removed by suction by opening the inlet 3 at a position where the soil layer thickness is 10 m, The radius becomes 17.3 m, and the deposit S of about 3000 m ³ is sucked and removed. Therefore, in the underwater deposit suction transfer device A and the underwater deposit suction transfer method of the present embodiment, the layer thickness of the suckable deposit S is increased and the amount of suction soil is increased as compared with the conventional case. Accordingly, the deposit S can be removed efficiently and economically.

  Further, since the outer tube 2 and the inner tube 4 are erected, the suction port of the outer tube 2 is compared with the case where the suction tube is installed on the deposit S or in the deposit S as in the prior art. 1 and the inlet 3 of the inner tube 4 are less likely to be blocked by foreign matter. Note that a net member can be laid in advance on the surface S1 of the deposit S, and foreign matter can be prevented from being sucked into the suction port 1 by this net member. And blockage of the inlet 3 by foreign matter is prevented.

  At the stage where the lowermost inlet 3 is opened and the deposit S in the suction removal range R set in advance is removed from the surface S1 of the deposit S, the inner tube 4 is pulled out from the outer tube 2 and collected. At this time, since the roller member 16 is provided in the inner tube 4, when the inner tube 4 is pulled out from the outer tube 2, the inner tube 4 is smoothly guided by the roller member 16, and the pulling out is easy. Yes. Furthermore, since the outer tube 2 and the inner tube 4 are not embedded in the deposit S as in the prior art, the outer tube 2 and the inner tube 4 can be separated and collected, so that maintenance can be performed easily and collected. The inner pipe 4 is inserted and installed in the outer pipe 2 installed at another position, and the deposit S can be sequentially removed by suction while diverting the inner pipe 4.

  Therefore, in the underwater deposit suction transfer apparatus A and the underwater deposit suction transfer method of the present embodiment, when the water W is circulated in the discharge pipe 5 so as to be discharged from the other end 5b, the outer pipe 2 Water W enters the gap H between the outer pipe 2 and the inner pipe 4 from the water intake 6, and this water W continuously flows through the gap H and enters the inside of the inner pipe 4 from the inlet 3. Is discharged through the inside of the discharge pipe 5. At this time, negative pressure is generated in the gap H between the outer tube 2 and the inner tube 4 due to the flow of the water W, and the deposit S is sucked into the gap H from the suction port 1 of the outer tube 2 by this negative pressure. The deposit S can be transported and removed together with the water W from the gap H through the inner tube 4 and from the inner tube 4 to the discharge tube 5. If the other end 5b of the discharge pipe 5 is disposed at least below the water surface W1, the water W is automatically circulated inside the discharge pipe 5, the gap H, and the inner pipe 4 according to the siphon principle. The deposit S can be removed by suction conveyance without requiring special energy.

  Further, since the outer tube 2 and the inner tube 4 are erected with the directions of the axes O1 and O2 in the vertical direction, it is not necessary to excavate a groove in the deposit S, for example. Further, when an arbitrary inlet 3 of the inner tube 4 is opened by the opening / closing device 10, the deposit S is collapsed in a mortar shape around the suction port 1 of the outer tube 2 corresponding to the inlet 3 and removed by suction. be able to.

  Thereby, the lower inlet 3 from the upper inlet 3 is opened in stages, and the deposits S are removed in stages by the suction ports 1 corresponding to the inlets 3 in each stage. The permeation flow length from the surface layer S1 of the deposit S to the suction port 1 becomes too large as in the prior art, so that it is not difficult to cause piping failure, and the layer thickness of the deposit S is several tens of meters. Even if it reaches, it becomes possible to remove the deposit S by suction conveyance efficiently and economically.

  Furthermore, since the outer tube 2 and the inner tube 4 are erected, the suction port 1 and the inner tube of the outer tube 2 are compared with the case where a conventional suction tube is installed on the deposit S or in the deposit S. The inlet 3 of the tube 4 is not easily blocked by foreign matter. In addition, since the outer tube 2 and the inner tube 4 are erected and are not embedded in the deposit S as in the prior art, the inner tube 4 can be pulled out from the outer tube 2 and separated and recovered, thereby maintaining maintenance. It becomes possible to improve. Furthermore, since the inner pipe 4 is inserted into the outer pipe 2 and installed, the outer pipe 2 can protect the inner pipe 4 and the opening / closing device 10 from driftwood and the like, and this improves the maintainability. It becomes possible.

  Further, by providing the opening / closing device 10 that opens and closes the plurality of introduction ports 3 of the inner tube 4, the introduction port 3 at a desired position can be appropriately opened / closed by the opening / closing device 10. Thereby, the introduction port 3 at a desired height (depth) position is opened, and the gap between the outer tube 2 and the inner tube 4 from the upper end portion 2a of the outer tube 2 to the introduction port 3 at the desired height position. Water W can be circulated through H, and the deposit S can be sucked from the suction port 1 in the range from the upper end 2a of the outer tube 2 to the introduction port 3 at this height position. That is, by appropriately opening and closing the plurality of introduction ports 3, it is possible to freely set the position at which the deposit S is sucked from the suction port 1 by generating a negative pressure.

  Furthermore, the deposit fall prevention means 20 for preventing the deposit S sucked from the suction port 1 of the outer tube 2 into the gap H between the outer tube 2 and the inner tube 4 from falling downward is provided. The deposit S sucked into the gap H between the tube 2 and the inner tube 4 can be reliably taken into the inner tube 4 from the desired inlet 3 and removed.

  As mentioned above, although one embodiment of the underwater deposit suction conveyance device and the underwater deposit suction conveyance method according to the present invention has been described, the present invention is not limited to the above embodiment, and departs from the gist thereof. It is possible to change appropriately within the range not to be.

  For example, in the present embodiment, the other end 5b of the discharge pipe 5 is arranged at least below the water surface W1, and water W is automatically supplied to the inside of the discharge pipe 5, the gap H, and the inner pipe 4 according to the siphon principle. However, the deposit S is sucked and removed from the suction port 1 by flowing water W through the discharge pipe 5, the gap H, and the inner pipe 4 using a suction pump or the like. You may do it.

  In the present embodiment, the opening of the upper end portion 2a of the outer tube 2 is described as the water intake port 6. However, for example, as shown in FIG. In this case as well, in this case, the water W taken in from the water intake 6 is circulated through the gap H, and the deposit S is removed from the suction port 1 by the generated negative pressure. It is possible to suck and transport and remove.

  Further, the opening 4d is provided in the lower end 4b of the inner tube 4, and the deposit S accumulated in the lower part of the outer tube 2 is sucked and removed from the opening 4d. A bottom cylindrical inner tube 4 may be used.

  In the present embodiment, the deposit fall preventing means 20 protrudes from the outer surface 4c of the inner tube 4 toward the inner surface 2c of the outer tube 2 and extends in the circumferential direction around the axis O2 of the inner tube 4. The bottom plate portion 21 is described as having a pair of side plate portions 22 and 23 that are connected to one end and the other end in the circumferential direction of the bottom plate portion 21 and extend upward along the direction of the axis O2. . On the other hand, the deposit fall prevention means according to the present invention projects the deposit S that protrudes from the outer surface 4 c of the inner tube 4 toward the inner surface 2 c of the outer tube 2 and enters the gap H from the suction port 1 of the outer tube 2. Accordingly, as long as it is possible to prevent the deposit S from falling to the lower part of the gap H, it is not particularly necessary to limit to the configuration of the present embodiment.

  For example, as shown in FIG. 9, the deposit fall prevention means 20 is configured by attaching a packer 27 that can be expanded and contracted to a predetermined position on the outer periphery of the inner tube 4 positioned below the pair of suction ports 1 and the introduction port 3. Also good. That is, as shown in FIGS. 9 (a) and 9 (b), air or water M is introduced into the rubber packer 27 attached to the outer periphery of the inner tube 4 (between the packer 27 and the outer surface 4c of the inner tube 4). The packer 27 is inflated (protruded) and brought into contact with the inner surface 2c of the outer tube 2 to close the gap H. The expanded packer 27 receives the deposit S sucked from the suction port 1, and receives the gap You may make it prevent falling to the lower part of H. Further, when the deposit S is sucked from the other suction port 1, the packer 27 contracts simply by discharging air or water, so that the gap H can be easily opened. As described above, when the deposit fall prevention means 20 is configured by including the packer 27 that functions like the bottom plate portion 21 of the present embodiment, members corresponding to the side plate portions 22 and 23 of the present embodiment. Is unnecessary.

  Further, when the deposit fall prevention means 20 is configured by including the bottom plate portion 21 and the pair of side plate portions 22 and 23, in the present embodiment, the side plate portions 22 and 23 are longer than the length of the suction port 1 in the axis O2 direction. However, the lengths of the side plate portions 22 and 23 are not necessarily larger than the length of the suction port 1. The deposit S sucked into the gap H (the space P surrounded by the bottom plate portion 21, the pair of side plate portions 22, 23, the inner surface 2c of the outer tube 2 and the outer surface 4c of the inner tube 4) from the suction port 1 It is preferable for the safety side that the length of the side plate portions 22 and 23 is larger than that of the suction port 1 as in the present embodiment, but the side plate portions 22 and 23 are at least the side plate portions. The deposit S that has entered the space P may have a length that does not collapse due to the angle of repose according to the positions 22 and 23 (and thus the circumferential length of the bottom plate portion 21).

  Further, in FIG. 3, the side plate portions 22 and 23 are formed in an L shape, and both side portions of the arc plate-like opening / closing plate 11 of the opening / closing device 10 are engaged with the side plate portions 22 and 23, respectively. 22 and 23 are illustrated as guiding the opening / closing plate 11 that moves forward and backward in the direction of the axis O <b> 2 by driving of the driving unit 14 of the opening / closing device 10. On the other hand, the pair of side plate portions 22 and 23 do not need to have such a guide function, and may exhibit a function of preventing the deposit S sucked from the suction port 1 from dropping into the lower portion of the gap H. Therefore, you may form simply in flat form.

  Furthermore, in this embodiment, by providing the roller member 16 in the inner tube 4, the inner tube 4 can be easily inserted into the outer tube 2 and the inner tube 4 can be pulled out from the outer tube 2. In addition, the roller member 16 has been described as forming a gap H of a predetermined size between the outer tube 2 and the inner tube 4. For example, the bottom plate portion 21 of the deposit fall prevention means 20 is used as a guide. The inner tube 4 can be inserted and pulled out, and the gap H can be secured by the bottom plate portion 21, and it is not necessary to limit the provision of the roller member 16.

DESCRIPTION OF SYMBOLS 1 Suction port 2 Outer tube 2a Upper end part 2b Lower end part 2c Inner surface 3 Inlet port 4 Inner tube 4a Upper end part 4b Lower end part 4c Outer surface 4d Opening part 5 Discharge pipe 5a One end part 5b Other end part 6 Water intake port 10 Opening and closing device 11 Opening / closing plate 12 Drive mechanism 13 Advance / retreat rod 14 Drive portion 15 Shaft portion 16 Roller member 20 Deposit fall prevention means 21 Bottom plate portion 22 Side plate portion 23 Side plate portion 24 Levee body 25 Float 26 Bottom plate concrete 27 Packer A Underwater deposit suction conveyance device H Clearance O1 Axis O2 of outer pipe Axis W of inner pipe W Water W1 Water surface R Suction removal range S Deposit S1 Surface (surface layer)
T Required length

Claims (4)

A device for sucking and conveying underwater deposits for sucking and removing deposits accumulated on the bottom of the water,
A plurality of suction ports are formed through the circumferential surface at intervals in the axial direction, and are formed with a water intake port for taking water into the interior, with the axial direction directed vertically and the water intake An outer pipe that is erected by placing the mouth in water and placing the suction port in the deposit;
A plurality of inlets are formed through the circumferential surface with an interval in the axial direction, an inner pipe inserted and installed in the outer pipe with a gap between the outer pipe, and
An opening and closing device for opening and closing the inlet;
An apparatus for sucking and conveying underwater deposits, comprising: a discharge pipe disposed with one end connected to the upper end of the inner pipe. The underwater deposit suction conveyance device according to claim 1,
Deposition that protrudes from the outer surface of the inner tube toward the inner surface of the outer tube, receives the deposit that has entered the gap from the suction port of the outer tube, and prevents the deposit from falling to the lower portion of the gap An apparatus for sucking and conveying underwater deposits, comprising an object fall prevention means. A method for sucking and conveying underwater deposits by sucking and removing deposits accumulated on the bottom of the water,
A plurality of suction ports are formed through the circumferential surface at intervals in the axial direction, and an outer tube formed with a water intake port for taking water inside is directed to the vertical direction in the axial direction. The water intake port is placed in water, and the suction port is placed in the deposit and erected,
An inner pipe in which a plurality of introduction ports are formed in the peripheral surface so as to be openable and closable with an interval in the axial direction is inserted and installed in the outer pipe with a gap between the outer pipe and the inner pipe. Connect one end to the upper end of the pipe and arrange the discharge pipe,
Open any inlet with a switchgear,
Water is circulated from the one end portion to the other end portion in the discharge pipe, the gap is circulated from the water intake port, and is sequentially circulated from the inside of the inner pipe to the discharge pipe through the open inlet port. Forming a flow of water
The underwater sediment, wherein the deposit is sucked into the gap from the suction port by the negative pressure generated in the gap due to the flow of the water, and discharged from the other end of the discharge pipe together with water. Suction conveyance method. In the suction conveyance method of the underwater sediment according to claim 3,
The plurality of inlets are opened in stages from the upper inlet in the axial direction of the inner pipe to the lower inlet, and the deposit is suctioned and removed from the surface side in stages. A method for sucking and transporting underwater sediments.

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