JP4114565B2 - Reservoir sand removal equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sand discharging device for discharging sand deposited in a reservoir such as a dam lake.
[0002]
[Prior art]
In recent years, dams have been buried in earth and sand at a faster rate than expected. Of the medium-scale dams with a total water storage of more than 1 million cubic meters, 44 dams already have more than half of the reservoir filled with sediment. Reported by the Ministry's survey.
[0003]
For this reason, it has become an important issue to remove the sediment from sediment reservoirs such as dam lakes and restore the amount of water stored during dam construction.
[0004]
Therefore, conventionally, various sand discharging methods (for example, refer to Patent Document 1) such as dredging with a suction pipe and dredging with a sand discharging gate have been adopted.
[0005]
However, the above-described conventional sand removal method has problems such as being unable to remove a wide range of sediment at a time and clogging of foreign matter in the sand discharge pipe.
[0006]
Accordingly, the present applicant has proposed a sand removal method (Japanese Patent Application No. 2002-062157) that can remove a wide range of sediment and prevent clogging of foreign matters.
[0007]
In the method of this prior application, the surface of the sediment around the sand pipe is covered with an impervious water-impervious material, and in that state, a sand discharge gate provided on the sand pipe is opened, and running water is supplied to the sand pipe. This allows the earth and sand to flow from the drainage pipe along with the flowing water.
[0008]
In this sand discharge method, water pressure acts directly on the water-impervious member and presses the sediment sediment below it with water pressure, so that the earth and sand flowing into the sand discharge pipe has a relatively small particle size that is carried by the water flow toward the sand discharge pipe. Since it is a small earth and sand and a foreign substance with a large diameter cannot be moved because it is pressed by the water-impervious member, it has an excellent effect that it can solve clogging due to the foreign substance and can remove the sediment in the range covered by the water-impervious member.
[0009]
However, in the above sand removal method, the sand discharge pipe is buried in the sediment at the start of the sand removal, so when the sand removal gate is opened, the sediment sediment layer in contact with the sand discharge pipe collapses due to its internal pressure, A highly concentrated debris stream flows down the sand discharge pipe. Therefore, since there is a very large pressure fluctuation downstream, there is a risk that facilities such as a sand discharge pipe and a sand discharge gate will be damaged. There is also a problem that dams without sand pipes cannot be used. Furthermore, there is a possibility that earth and sand may be caught in the sand removal gate and the sand removal gate may not be closed, which leaves a problem in practical implementation.
[0010]
Accordingly, the present applicant has further improved the above-mentioned sand removal method and proposed a reservoir sand removal method and sand removal apparatus (Japanese Patent Application No. 2003-61380) that can perform sand removal without using a sand removal gate.
[0011]
As shown in FIG. 3, this sand discharge method is a sand discharge method in which the earth and sand 2 deposited in a reservoir 1 such as a dam lake is sucked by the sand discharge pipe 3 to remove the sand. The sheet-like member 5 is laid, and the suction port 6 of the sand discharge pipe 3 is made to face the surface 4 of the sediment earth and sand 2 from the back surface of the sheet-like member 5 so as to perform suction sand removal. .
[0012]
According to this, a water flow can be created between the sheet-like member 5 and the sediment 2 by suction of the sand removal pipe 3, and the sediment 2 can be efficiently removed from a wide range by the sweeping action by this water flow. In addition to being able to be sucked in, the conventional sand removal gate is not required, so that an excellent effect that it can be applied even to a dam without a sand removal gate is achieved.
[0013]
[Patent Document 1]
JP-A-8-13453 [0014]
[Problems to be solved by the invention]
By the way, sedimentary sediment deposited in a reservoir such as a dam is composed of sand, silt or the like having various particle sizes. However, it has been experimentally found that the above-mentioned sand discharging method and sand discharging device limit the particle size of earth and sand that can be efficiently discharged. For example, when the sedimentary sediment 2 to be discharged is composed of fine sand (particle size of about 0.3 mm) to coarse sand (particle size of about 1.0 mm), it is between the sheet-like member 5 and the sedimentary sediment 2. However, when the sediment 2 is composed of fine particles such as silt (particle size of about 0.04 mm), it is efficient. It was found that suction sand removal was not performed sufficiently. This is because the sheet-like member 5 sticks to the surface of the sediment earth and sand 2 due to suction of the sand removal pipe 3 because the viscosity of silt is large and the water permeability coefficient is small, and no water flow is generated.
[0015]
Accordingly, the present invention has been devised to solve the above-described problem, and an object thereof is to provide a reservoir sand discharger that can efficiently discharge sand regardless of the particle size of the sediment. .
[0016]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a sand discharger for sucking and discharging sediment deposited in a reservoir such as a dam lake by a sand discharge pipe. A sheet-like member that extends outward in the direction and covers the surface of the sedimentary earth and sand is provided, and a water channel that is a flow path space that connects the peripheral edge of the sheet-like member to the suction port is formed on the back surface of the sheet-like member Then, the sediment on the back side of the sheet-like member is configured to be sucked and discharged together with water, and the water channel is formed by a ridge formed on the sheet-like member .
[0018]
Moreover, what provided the reinforcing wire in the top part and trough part of the said ridge | line | mouth is respectively preferable.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.
[0020]
FIG. 1 is a plan view and a side view showing a preferred embodiment of a sand discharging device for a reservoir according to the present invention, FIG. 2 is a sectional view of a sheet-like member, and FIG. 3 is an overall configuration diagram of the sand discharging device.
[0021]
As shown in FIG. 3, in the sand discharging device 7, a sand discharging pipe 3 for sucking and discharging the sediment earth and sand 2 is suspended from a trolley 8 floated in the reservoir 1. A sheet-like member 5 having a sufficient laying area is connected to the suction port 6 of the sand discharge pipe 3. The sheet-like member 5 is laid on the surface 4 of the sediment 2 to be dredged.
[0022]
This sheet-like member 5 is formed of a water-impervious or hardly water-permeable cloth, resin, rubber, or the like, and has the flexibility of following the surface 4 of the deposited earth and sand 2 and the property of sinking without floating in water. Yes. The sheet-like member 5 may be formed by providing a mesh-like reinforcing material on the cloth, resin, rubber, or the like.
[0023]
The shape of the sheet-like member 5 is circular or polygonal (circular in the present embodiment), and the diameter of the sheet-shaped member 5 takes into consideration the range in which the water flow described later acts and the range in which the sedimentary sediment 2 by the sheet-like member 5 is pressed and sealed In this case, it should be about 100 m, but ones in the range of several tens to several tens of meters can be used.
[0024]
Specifically, the sheet-like member 5 is laid down in such a manner that the sheet-like member 5 is first folded in a state where it is folded on the trolley 8, and the sheet-like member 5 is sunk to the target position of the bottom of the water. Spread and lay in. In addition, the sheet-like member 5 may be spread near the water surface or the bottom of the water and gradually submerged in that state.
[0025]
A sand discharge hole 9 is formed in the center of the sheet-like member 5. The sand discharge pipe 3 is connected to the sheet-like member 5 so that the suction port 6 of the sand-discharge pipe 3 passes through the sand removal hole 9 of the sheet-like member 5 and faces the accumulated sediment 2 on the back side from the front surface portion of the sheet-like member 5. Is done.
[0026]
The sand discharge pipe 3 is made of a flexible resin pipe, and its diameter is preferably large in consideration of sand discharge efficiency, but is preferably about 300 mm in consideration of workability. In addition, the sand exhaust pipe 3 may use not only a resin pipe but a part steel pipe.
[0027]
The sand discharge pipe 3 may be connected in advance before or after the sheet-like member 5 is laid. The sheet-like member 5 and the sand discharge pipe 3 are connected by forming a flange 10 around the suction port 6 at the tip of the sand discharge pipe 3 and attaching the flange 10 to the sand discharge hole 9 of the sheet-like member 5 in advance. A receiving seat (not shown) is formed, and the flange 10 is installed on the upper side of the receiving seat of the sheet-like member 5 and connected by fixing means such as bolts and nuts. A traction rope 24 extending from the carriage 8 is connected to the flange 10. The tow rope 24 is wound around a hoisting machine 25 provided on the carriage 8 so that the depth of the sand discharge pipe 3 can be adjusted.
[0028]
The length of the drainage pipe 3 is the sum of the depth of the reservoir 1, the distance from the water surface above the dredging position to the dam body, and the height from the upper surface of the dam body to the water surface of the reservoir 1. It is formed sufficiently long (although it differs depending on the water depth of the reservoir, about several hundreds of meters). For this reason, a predetermined length is sequentially connected to form the required length.
[0029]
The sand discharge pipe 3 is supported on the base boat 8, and the discharge port (not shown) extends from the base boat 8 so as to straddle the upper part of the dam dam body and to be located downstream of the dam dam body. To do. A suction sand discharge pump 11 and a valve 12 are appropriately connected to the sand discharge pipe 3.
[0030]
By this pump 11, the sediment 2 on the back surface of the sheet-like member 5 is sucked together with water from the suction port 6 of the sand discharge pipe 3, and discharged from the discharge port 14 located downstream of the dam dam body to the downstream side. Is done.
[0031]
The configuration described above is the same as the sand discharging method and sand discharging device of the prior application (Japanese Patent Application No. 2003-61380).
[0032]
By the way, in the present invention, as shown in FIGS. 1 and 2, water that is a flow path space that is connected to the suction port 6 of the sand discharge pipe 3 from the peripheral portion 15 of the sheet-like member 5 on the back surface of the sheet-like member 5. A groove 16 is formed, and the sedimentary earth and sand 2 on the back surface side of the sheet-like member 5 is configured to be sucked and sanded together with water.
[0033]
The water channel 16 is formed by a flange 17 formed on the sheet-like member 5. Specifically, the water channel 16 is surrounded and partitioned by the lower surface of the ridge 17 and the surface 4 of the sediment 2. The flange 17 is formed by bending the sheet-like member 5 into a fan shape, and a reinforcing wire 21 is provided on each of the top portion 18 and the valley portion 19 (see FIG. 2). The trough 17 is formed to have a height of about several centimeters so that a water flow is generated in the water channel 16 and the sediment earth and sand 2 can flow along with the water flow. The water channel 16 has an isosceles triangle cross-sectional shape. The cross-sectional shape is not limited to this, and may be a semicircular shape or a polygonal shape.
[0034]
The reinforcing wire 21 is made of, for example, a wire having a diameter of about several millimeters, extends in the radial direction of the sheet-like member 5 and is arranged radially, and is provided above the top portion 18 and the valley portion 19 of the flange 17. The reinforcing wire 21 is fastened and fixed to the sheet-like member 5 by fixing means such as strings (not shown) provided at predetermined pitch intervals in the radial direction. When the sheet-like member 5 is transported, the reinforcing wire 21 is cut for each transportable length (length that can be loaded on a truck) and is connected after transport.
[0035]
Between the reinforcing wire 21 of the top portion 18 of the adjacent flange 17 and the reinforcing wire 21 of the valley portion 19, the connecting wire 22 is bridged at a predetermined pitch, and the positional relationship between the reinforcing wire materials 21 is kept constant. It is designed to retain the shape. The connecting wire 22 is flexible, and the sheet-like member 5 is folded during transportation, and the connecting wire 22 extends linearly in water so that the shape of the flange 17 can be maintained.
[0036]
The reinforcing wire 21 may be attached to the back side of the sheet-like member 5.
[0037]
The said sheet-like member 5 is divided | segmented for every arc of 60 degree | times, for example, is folded by the ridge 17 part, and conveys it in the shape of a fan. Then, the sheet-like members 5 and the reinforcing wire members 21 that have been divided on the carriage 8 or on the water surface after transportation are connected and submerged in the bottom of the water. The sheet-like members 5 are connected to each other by Velcro (registered trademark) or heat welding so that the water-tightness of the sheet-like members 5 can be maintained.
[0038]
Thereafter, the sand discharging device 7 is set by connecting the sheet-like member 5 and the sand discharging pipe 3 or the like.
[0039]
According to the sand discharging device 7 having the above-described configuration, as shown in FIG. 2A, the water channel 16 is formed on the back surface of the sheet-like member 5 in a state where the sheet-like member 5 is placed on the sedimentary earth and sand 2. Is done. Thus, when suction from the sand discharge pipe 3 is started, a water flow is generated in the water channel 16 from the peripheral edge 15 of the sheet-like member 5 toward the sand discharge hole 9. At this time, since the water channel 16 has a height of several centimeters, the flow velocity of the water flow is high, and the sedimentary sediment 2 is washed away by the sweeping action. Although the inside of the water channel 16 becomes negative pressure due to the suction of the sand discharge pipe 3, the reinforcing wire 21 and the connecting wire 22 are provided, so that the shape of the water channel 16 can be maintained. In the unlikely event that the negative pressure is large and the water channel 16 is crushed against the reinforcing wire 21, the water flow is temporarily stopped, so the negative pressure disappears and the reinforcing wire 21 recovers to its original shape. The groove 16 is secured again.
[0040]
As shown in FIGS. 2 (b) to 2 (c), as the accumulated earth and sand 2 are discharged, the earth and sand on the surface gradually flows, and finally, the remaining part of the earth and sand 23 collapses and becomes a sheet. The shaped member 5 sinks. While repeating this state, the sediment 2 is sequentially discharged.
[0041]
When the sand is discharged, the sinking speed of the sand discharging pipe 3 is adjusted by the hoist 25 so that the suction port 6 of the sand discharging pipe 3 is slightly lifted from the surface 4 of the sediment earth and sand 2. In addition, more efficient sand removal can be performed.
[0042]
As described above, according to the present embodiment, the water channel 16 is positively formed to generate a water flow, so that the sediment 2 is a silt having a small intergranular gap and a small hydraulic conductivity. Even if it is comprised by the fine particle of this, the sheet-like member 5 does not stick to the sedimentation earth and sand 2, and can perform efficient sand removal. Moreover, even if the sediment earth and sand 2 is comprised from fine sand to coarse sand, efficient sand removal can be performed.
[0043]
FIG. 4 is a plan view showing a sheet-like member 5 according to another embodiment. The sheet-like member 5 is different from the one shown in FIG. 1 in the outer shape and the shape of the water channel 16, and the other configurations are the same as those in the above embodiment.
[0044]
The sheet-like member 5 is formed in a regular hexagonal shape. The water channel 16 has six main line portions 26 extending from the sand discharge hole 9 at the center of the sheet-like member 5 to the corner portion 28 of the peripheral edge portion 15 and branches from the main line portion 26 toward the side portion 29 of the peripheral edge portion 15. And a plurality of branch line portions 27 branched in a shape. Each branch line portion 27 extends in a direction orthogonal to the side portion 29, and the branch line portions 27 are parallel to each other in a range between adjacent main line portions 26.
[0045]
In the figure, a thick line in the sheet-like member 5 indicates a mountain fold portion of the water channel 16, and a thin line indicates a valley fold portion of the water channel 16.
[0046]
FIG. 5 is a plan view showing a sheet-like member 5 of still another embodiment. The sheet-like member 5 is different from the one shown in FIG. 1 in the shape of the water channel 16, and the other configurations are the same as those in the above embodiment.
[0047]
The water channel 16 of the sheet-like member 5 includes a linear portion 31 that extends radially in the radial direction and a curved portion 32 that extends in the circumferential direction at a radially intermediate portion and is formed in a circular shape. The straight line part 31 and the curved line part 32 are connected to each other at right angles, and the straight line part 31 inside the curved line part 32 is half of the straight line part 31 outside. According to the said structure, the water channel 16 around the sand removal hole 9 can be decreased, and the suction efficiency by the sand discharge pipe 3 can be improved.
[0048]
In the figure, a thick line in the sheet-like member 5 indicates a mountain fold portion of the water channel 16, and a thin line indicates a valley fold portion of the water channel 16.
[0049]
FIG. 6 is a cross-sectional view showing a water groove 16 portion of the sheet-like member 5 of still another embodiment.
[0050]
The water channel 16 of the sheet-like member 5 is formed by providing wall bodies 33 having a predetermined height (for example, several centimeters) at predetermined pitch intervals on the back surface of the sheet-like member 5. The wall 33 is composed of a square pipe or the like, and is fastened and fixed to the sheet-like member 5 by a fixing means such as a string (not shown). The wall body 33 is not limited to a square pipe, and may be formed of other materials as long as it sinks in water, and the shape is not limited to a rectangular cross section. The wall 33 extends from the peripheral edge 15 of the sheet-like member 5 to the sand removal hole 9, and the water channel 16 is formed in the same manner.
[0051]
That is, in the present embodiment, by providing the wall 33 on the back surface of the sheet-like member 5, the wall body 33 becomes a leg and the sheet-like member 5 is lifted, and between the back surface and the surface 4 of the sediment earth and sand 2. A space is formed, which becomes the water path 16.
[0052]
Also in the present embodiment, a water flow is generated in the water channel 16, and efficient sand removal can be performed by the sweeping action.
[0053]
The wall body 33 is not limited to be provided continuously in the longitudinal direction, and may be provided intermittently with an interval in the longitudinal direction.
[0054]
【The invention's effect】
In short, according to the present invention, an excellent effect is achieved that sand can be discharged efficiently regardless of the particle size of the sediment.
[Brief description of the drawings]
FIG. 1A is a plan view and FIG. 1B is a side view showing a preferred embodiment of a sand removal apparatus for a reservoir according to the present invention.
2A is a cross-sectional view of a sheet-like member, FIG. 2A is a cross-sectional view illustrating a state of a first step of sand removal, FIG. 2B is a cross-sectional view illustrating a state of a second step of sand discharge, ) Is a cross-sectional view showing the state of the third step of sand removal.
FIG. 3 is an overall configuration diagram of a sand removal device.
FIG. 4 is a plan view showing a sheet-like member according to another embodiment.
FIG. 5 is a plan view showing a sheet-like member according to still another embodiment.
FIG. 6 is a cross-sectional view showing a water channel portion of a sheet-like member according to still another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reservoir 2 Sedimentation sand 3 Sedimentation pipe 4 (Sedimentation earth and sand) surface 5 Sheet-like member 6 Suction port 7 (of sand removal pipe) Sand discharger 15 Peripheral part 16 Water channel 17 襞 18 Top part 19 Valley part 21 Reinforcement wire

Claims (2)

In a sand discharger that sucks sediments that accumulate in reservoirs such as dam lakes by using a sand pipe, the surface of the sediment is expanded to the suction port of the sand pipe and radially outward. A sheet-like member covering the sheet-like member is formed, and a water channel, which is a flow path space connected from the peripheral edge of the sheet-like member to the suction port, is formed on the back surface of the sheet-like member, and the sediment on the back side of the sheet-like member A sand discharging device for a reservoir, wherein the water channel is formed by a ridge formed on the sheet-like member . The reservoir sand discharger according to claim 1 , wherein reinforcing wire rods are provided at the top and trough portions of the trough .

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