JP6894763B2 - Shallow manufacturing method and earth and sand injection equipment - Google Patents

Description

The present invention relates to a shallow field manufacturing method and a sediment injection device. More specifically, when sediment is injected into water, it is possible to form a shallow field in a shallow water area with high work efficiency while suppressing the diffusion of pollution. It relates to a shallow manufacturing method and a sediment input device.

A method of using a double-tube tremie device is known when pouring earth and sand into a predetermined range of the bottom of a water such as the sea or a river (see, for example, Patent Document 1). In such a double pipe tremie device, the water discharged from the lower end opening of the inner pipe rises between the inner pipe and the outer pipe, and a circulating flow is generated again inflowing into the inner pipe. When the earth and sand put into the inner pipe is discharged from the lower end opening of the inner pipe, a part of the floating earth and sand is circulated by the circulating flow, so that the diffusion of pollution by the put in earth and sand can be suppressed.

However, since a circulation path having a certain length is required to generate the above-mentioned circulation flow, it is not possible to generate a sufficient circulation flow by the conventional device in a water area where the water depth is shallow. Further, in the conventional device, since the double pipe is set in a vertical state from the water surface to the water bottom, the range in which sediment is deposited on the water bottom is limited to the range directly below the double pipe. Therefore, in order to deposit sediment over a wide area on the bottom of the water, it is necessary to move the double pipe horizontally frequently, and it is difficult to improve the work efficiency.

Japanese Unexamined Patent Publication No. 2011-69076

An object of the present invention is to provide a method for producing a shallow field and an earth and sand injection device capable of forming a shallow field in a shallow water area with high work efficiency while suppressing the diffusion of pollution when the earth and sand are injected into water. It is in.

In order to achieve the above object, in the shallow manufacturing method of the present invention, the input pipe is installed so as to extend from the water to the water, and a recirculation pipe is installed adjacent to the input pipe in the vicinity of the lower end opening of the input pipe. The lower end opening of the recirculation pipe is arranged in the water, and the inside of the recirculation pipe is communicated with the inside of the input pipe at a position in the middle of the longitudinal direction of the input pipe, so that the input pipe is bent or inclined from the water surface toward the water bottom. Then, the lower end portion thereof is set laterally, an opening / closing lid that can be opened and closed is installed at the lower end opening of the input pipe, and earth and sand are injected from the upper end opening of the input pipe to inside the input pipe. The opening / closing lid is opened upward by pressing the flowing earth and sand, and the earth and sand are discharged from the lower end opening of the input pipe located below the opening / closing lid in the opened state and deposited on the bottom of the water. A part of the water flowing through the inside of the input pipe toward the lower end opening is returned to the inside of the input pipe from the vicinity of the lower end opening of the input pipe through the lower end opening of the recirculation pipe and through the recirculation pipe. It is characterized in that a circulating flow that circulates between the input pipe and the recirculation pipe is generated.
In another shallow manufacturing method of the present invention, the input pipe is installed so as to extend from the water to the water, a recirculation pipe is installed adjacent to the input pipe, and the input pipe is installed near the lower end opening of the input pipe. The lower end opening of the recirculation pipe that communicates with the inside of the input pipe is arranged, and the upper end opening of the recirculation pipe that communicates with the inside of the input pipe is arranged at a position in the middle of the longitudinal direction of the input pipe. The lower end of the recirculation pipe is set laterally by bending or inclining toward the bottom of the water, and the lower end opening of the recirculation pipe is located on the upper side surface of the input pipe in the middle of the longitudinal direction near the lower end opening of the injection pipe. The recirculation pipe having a diameter smaller than that of the input pipe extends on the outer surface of the input pipe along the input pipe, and earth and sand are injected from the upper end opening of the input pipe and discharged from the lower end opening thereof. By depositing the earth and sand from the upper end opening of the input pipe and charging the earth and sand from the upper end opening of the input pipe, the water level inside the input pipe is lowered from the upper end opening of the recirculation pipe communicating with the input pipe. By allowing the water existing inside the recirculation pipe to flow into the inside of the input pipe through the upper end opening of the recirculation pipe, a part of the water flowing through the inside of the input pipe toward the lower end opening is discharged. It is characterized in that a circulating flow that circulates between the input pipe and the recirculation pipe is generated by recirculating from the vicinity of the lower end opening of the input pipe through the lower end opening of the recirculation pipe to the inside of the input pipe through the recirculation pipe. And.

The earth and sand injection device of the present invention includes an input pipe installed on a floating body and extending from the water to the water, and a return pipe installed adjacent to the input pipe, and the return pipe is provided near the lower end opening of the input pipe. A circulation path formed by the input pipe and the return pipe, in which the lower end opening of the pipe is arranged and the inside of the return pipe communicates with the inside of the input pipe at a position in the middle of the longitudinal direction of the input pipe . It has an openable / closable opening / closing lid installed at the lower end opening of the input pipe, and the input pipe is bent or inclined from the water surface toward the bottom of the water, and the lower end portion thereof is set laterally. open the lid by pressing the thrown-in sediment from the set top opening of the feeding pipe is upward, from said lower end opening of the injection tube which is located below the lid of the open position A configuration in which earth and sand are discharged and a part of water flowing inside the input pipe toward the lower end opening circulates in the circulation path from the vicinity of the lower end opening of the input pipe through the lower end opening of the return pipe. It is characterized by having made it.
Another earth and sand injection device of the present invention includes an input pipe installed on a floating body and extending from the water to the water, and a return pipe installed adjacent to the input pipe, near the lower end opening of the input pipe. The lower end opening of the recirculation pipe is arranged, and the inside of the recirculation pipe communicates with the inside of the input pipe at a position in the middle of the longitudinal direction of the input pipe, and a circulation path formed by the input pipe and the recirculation pipe. The inlet pipe is bent or tilted from the water surface toward the bottom of the water, and the lower end portion thereof is set so as to be laterally oriented, and the lower end opening of the return pipe is the vicinity of the lower end opening of the inlet pipe. The recirculation pipe, which is arranged on the upper side surface of the input pipe at a position in the middle of the longitudinal direction and has a diameter smaller than that of the input pipe, extends along the input pipe to the outer surface of the input pipe and is set. The earth and sand introduced from the upper end opening of the input pipe is discharged from the lower end opening of the input pipe, and the earth and sand is input from the upper end opening of the input pipe, so that the recirculation communicating with the input pipe is performed. The water level inside the input pipe is lower than the upper end opening of the pipe, and the water existing inside the recirculation pipe flows into the inside of the input pipe through the upper end opening of the recirculation pipe. It is characterized in that a part of water flowing inside the pipe toward the lower end opening circulates in the circulation path from the vicinity of the lower end opening of the input pipe through the lower end opening of the recirculation pipe.

According to the present invention, a recirculation pipe is installed adjacent to the inlet pipe extending from the water to the water, the lower end opening of the recirculation pipe is arranged near the lower end opening of the inlet pipe, and the inside of the recirculation pipe is inserted into the inlet pipe. A circulation path is formed by the input pipe and the return pipe by communicating with the inside of the input pipe at a position in the middle of the longitudinal direction. Then, since the input pipe is bent or tilted from the water surface toward the water bottom and the lower end portion thereof is set laterally, the circulation path can be lengthened even if the water depth is shallow. Therefore, even in a shallow water area, by injecting earth and sand from the upper end opening of the input pipe, it is possible to sufficiently generate a circulating flow circulating in the circulation path. Since a part of the floating earth and sand is circulated by the circulating flow in the vicinity of the lower end opening of the input pipe, the diffusion of pollution can be suppressed even if the earth and sand are discharged from the lower end opening of the input pipe. Moreover, since the earth and sand are discharged sideways from the lower end opening of the input pipe, it becomes easy to deposit the earth and sand in a wide range of the water bottom, which is advantageous for efficiently forming a shallow field in a shallow water area.

It is explanatory drawing which illustrates the earth and sand throwing device of this invention in the front view. It is explanatory drawing which illustrates the earth and sand throwing device of FIG. 1 in a plan view. It is explanatory drawing which illustrates the process of manufacturing a shallow field from the front view. It is explanatory drawing which illustrates the process of FIG. 3 in a plan view. It is explanatory drawing which schematically exemplifies the inside of the input pipe of FIG. 3 in the vertical cross-sectional view. It is explanatory drawing which illustrates the state in which the input pipe of FIG. 2 is rotated. It is explanatory drawing which illustrates another embodiment of the earth and sand throwing device in a front view.

Hereinafter, the shallow-field manufacturing method and the earth and sand injection device of the present invention will be described based on the embodiment shown in the figure.

The present invention is applied when depositing earth and sand on the bottom of a shallow water area to form a shallow field. The water depth of the target water area is, for example, 1 m or more and less than 5 m, or 2 m or more and 4 m or less. By depositing earth and sand on the bottom of the water, a shallow field with a water depth of, for example, 0.5 m or more and 2 m or less is formed.

The earth and sand injection device 1 of the present invention illustrated in FIGS. 1 and 2 includes an input pipe 2 installed on a floating body 13 and extending from the water to the water, and a reflux pipe 3 installed adjacent to the input pipe 2. It has. The input pipe 2 extends from the floating body 13 so as to be bent or inclined toward the bottom of the water, and its lower end is set laterally. This horizontal orientation is not limited to a perfect horizontal orientation, but includes an orientation that is tilted up and down by about 45 ° with respect to the horizontal orientation.

Therefore, as the input pipe 2 and the return pipe 3, a flexible pipe body such as a resin pipe is used. Even if it is a metal tube, it can be used as an input tube 2 or a perfusion tube 3 as long as it has a flexibility such as a bellows tube. Even if the input pipe 2 and the reflux pipe 3 are not specified to have a flexible total length, it is sufficient that the input pipe 2 and the return pipe 3 have a specification having flexibility in a part of the total length and the lower end portion thereof can be set in the lateral direction.

It is preferable that the inner surfaces of the input pipe 2 and the return pipe 3 have no unevenness or small unevenness (smooth inner surface) in order to prevent clogging of the earth and sand S. Further, if each of the input pipe 2 and the return pipe 3 has a constant cross-sectional area in which the cross-sectional area does not change in the longitudinal direction, the water W and the earth and sand S inside can easily flow smoothly.

In this embodiment, the input pipe 2 and the return pipe 3 have a flexible overall length, and the return pipe 3 extends along the longitudinal direction of the input pipe 2. Then, the upper end opening 2a of the input pipe 2 is connected to the lower end of the hopper 11 placed in the central portion of the floating body 13 in a plan view. The input pipe 2 is bent from the water surface toward the water bottom, and its lower end is set along the water bottom in the lateral direction (generally in the horizontal direction). A belt conveyor 12 is arranged above the hopper 11.

The floating body 13 may be any as long as it can stably hold the input pipe 2. In this embodiment, eight rectangular pontoons 13a are connected in a ring shape in a plan view to form a floating body 13 having a cavity in the center in a plan view.

The lower end opening 3b of the reflux pipe 3 is arranged in the vicinity of the lower end opening 2b of the input pipe 2. The lower end opening 3b can be arranged on the lower side of the lower end opening 2b, but is preferably arranged on the upper side or the side. It is more preferable to arrange the lower end opening 3b above the lower end opening 2b as in this embodiment.

The upper end opening 3a of the return pipe 3 is connected and arranged at a position in the middle of the longitudinal direction of the input pipe 2. As a result, the inside of the return pipe 3 communicates with the inside of the input pipe 2 at a position halfway in the longitudinal direction of the input pipe 2, and a circulation path is formed by the input pipe 2 and the return pipe 3. If the length of the circulation path is too short, circulation flow is less likely to occur. Therefore, in order to lengthen the circulation path, it is preferable that the upper end opening 3a of the return pipe 3 is as close as possible to the upper end opening 2a of the input pipe 2 and is arranged below the water surface in the water area.

Further, it is preferable that the cross-sectional area of the reflux pipe 3 is, for example, 80% to 100% with respect to the cross-sectional area of the input pipe 2. When the size of the cross-sectional area of the input pipe 2 and the return pipe 3 is made to be about the same, it becomes easy to generate a sufficient circulating flow. In order to increase the cross-sectional area of the reflux pipe 3, a plurality of reflux pipes 3 may be provided. When a plurality of recirculation pipes 3 are provided, it is preferable that the total cross-sectional area of each recirculation pipe 3 is 80% to 100% with respect to the cross-sectional area of the input pipe 2.

In this embodiment, the lower end opening 2b is provided with an opening / closing lid 4 that can be opened / closed. The opening / closing lid 4 can be optionally provided. A wire 8b is connected in the vicinity of the lower end opening 2b. The wire 8b is wound and unwound by a winch 8a installed on the floating body 13. When the wire 8b is wound by the winch 8a, the lower end opening 2b moves upward, and when the wire 8b is unwound by the winch 8a, the lower end opening 2b moves downward. Therefore, the winch 8a and the wire 8b are vertical movement mechanisms 8 that move the lower end opening 2b up and down. The vertical movement mechanism 8 can be optionally provided.

The middle of the wire 8a is supported by being hung around the support roller 9. The support roller 9 can be fixed at a predetermined position with respect to the pontoon 13, but in this embodiment, the support roller 9 is attached to the tip of the support rod 10. The rear end of the support rod 10 is rotatably attached via a hinge, and the support rod 10 is undulating. Further, the support rod 10 has a telescopic structure, and its length can be changed.

A turntable 6 is placed on the floating body 13. The lower surface of the central portion of the turntable 6 is a recess 6a. By engaging the peripheral surface of the recess 6a with the engaging portion 13b protruding from the upper surface of the floating body 13, the rotating disk 6 can rotate around the central portion of the floating body 13 in a plan view.

A drive motor 7 fixed above the pontoon 13 is in contact with the outer peripheral surface of the turntable 6. The rotary disk 6 is rotated by rotationally driving the drive motor 7. The winch 8, the support rod 10, and the hopper 11 are fixed to the turntable 6. Therefore, the upper end portion of the input pipe 2, the hopper 11, the winch 8, the support roller 9, and the support rod 10 rotate together with the turntable 6.

When the upper end portion of the input pipe 2 rotates together with the turntable 6, the horizontal position of the lower end opening 2b of the input pipe 2 changes. Therefore, the turntable 6 and the drive motor 7 are rotating mechanisms 5 that rotate the lower end opening 2b in the horizontal direction. The rotating mechanism 5 can be optionally provided.

The procedure of the method for producing the shallow field of the present invention is illustrated below.

The floating body 13 in which the earth and sand input device 1 is installed is moved to the construction target water area and moored, and the earth and sand input device 1 is arranged in the construction target water area. In this water area, the input pipe 2 extends from the water to the water. Then, the vertical movement mechanism 8 is operated to bend or incline the input pipe 2 as illustrated in FIGS. 1 and 2, and set the lower end portion thereof in the lateral direction. With the input pipe 2 set in this way, the lower end opening 3b of the recirculation pipe 3 is arranged in the vicinity of the lower end opening 2b of the input pipe 2, and the inside of the recirculation pipe 3 is located in the middle of the longitudinal direction of the input pipe 2. It communicates with the inside of the input pipe 2.

It is preferable that the lower end of the input pipe 2 is positioned slightly above the bottom of the water so as not to come into contact with the bottom of the water, and is set so as to be within 15 ° vertically with respect to the horizontal. At this time, the support roller 9 is positioned at an appropriate position by adjusting the length and the undulation angle of the support rod 10 so that the wire 8b does not come into contact with the floating body 13.

Next, the earth and sand S is repeatedly put into the hopper 11 as illustrated in FIGS. 3 and 4. Also placing the sediment S by using a belt conveyor 12 as in this embodiment, it may be dosed using a bucket or the like. The earth and sand S charged into the hopper 11 enters the inside of the input pipe 2 from the upper end opening 2a of the input pipe 2 and flows toward the lower end opening 2b. The flowing earth and sand S is opened by pressing the opening / closing lid 4, and is discharged to the outside through the lower end opening 2b. The earth and sand S discharged from the lower end opening 2b is deposited on the water bottom in the lateral direction of the lower end opening 2b.

Here, when the earth and sand S is charged into the input pipe 2, the density of the water W (mixed water with the earth and sand S) inside the input pipe 2 becomes higher than the density of the surrounding water W. As illustrated, the water level inside the input pipe 2 drops. When the water level inside the input pipe 2 is lower than the upper end opening 3a of the return pipe 3, the water W existing in the return pipe 3 flows into the inside of the input pipe 2 through the upper end opening 3a.

In the vicinity of the lower end opening 2b, the water W discharged from the lower end opening 2b diffuses to the outside, but a part of the water W flows into the lower end opening 3b. A part of the water W flowing in the inlet pipe 2 toward the lower end opening 2b returns to the inside of the inlet pipe 2 from the vicinity of the lower end opening 2b through the lower end opening 3b of the reflux pipe 3 and through the reflux pipe 3. To do. As a result, a circulation flow is generated in which the input pipe 2 and the return pipe 3 are used as a circulation path.

The lowered water level inside the input pipe 2 rises due to the reaction, and since this decrease and rise are repeated, the water level inside the input pipe 2 fluctuates up and down. Then, if a new earth and sand S is injected into the input pipe 2 before the earth and sand S charged into the input pipe 2 is discharged from the lower end opening 2b, this circulating flow continues without interruption.

Since a part of the earth and sand S floating in the vicinity of the lower end opening 2b of the input pipe 2 circulates in the circulation path (injection pipe 2 and the return pipe 3) together with the water W by the circulation flow, the earth and sand S is discharged from the lower end opening 2b. Can also suppress the spread of pollution. Since the fine earth and sand S that causes pollution tends to float upward, if the lower end opening 3b is arranged above the lower end opening 2b as in this embodiment, the fine earth and sand S can be easily circulated to suppress the diffusion of pollution. Becomes more and more advantageous.

Moreover, in the present invention, since the input pipe 2 is bent or inclined from the water surface toward the water bottom and the lower end portion thereof is set in the lateral direction, the circulation path can be lengthened even if the water depth is shallow. Therefore, even in a shallow water area, by charging the earth and sand S from the upper end opening 2a of the charging pipe 2, it is possible to sufficiently generate a circulating flow circulating in the circulation path. In a water area where the water depth from the water surface to the water bottom is 1 m or more and less than 5 m, the lengths of the input pipe 2 and the return pipe 3 may be set longer than the water depth by 1 m or more, more preferably 2 m or more.

Further, in the present invention, the earth and sand S is discharged sideways from the lower end opening 2b. Therefore, as compared with the conventional device that discharges the earth and sand S vertically downward, the present invention makes it easier to deposit the earth and sand S in a wide range of the bottom of the water, which is advantageous for efficiently forming a shallow field in a shallow water area. Become.

In this embodiment, the opening / closing lid 4 prevents the earth and sand S from being discharged to the outside from the lower end opening 2b at an excessive discharge rate. Therefore, it is advantageous to suppress the diffusion of pollution due to the discharged earth and sand S.

In this embodiment, as illustrated in FIG. 6, the rotation mechanism 5 is used to change the horizontal position of the lower end opening 2b of the input pipe 2, and the earth and sand S is discharged from the lower end opening 2b at each changed position. can do. Therefore, even if the floating body 13 is not moved, the earth and sand S can be deposited in a relatively wide range, so that a shallow field can be formed more efficiently.

In this embodiment, the lower end opening 2b can rotate 360 ° around the hopper 11 in a plan view, but the rotation angle is not limited to this. For example, the rotation angle of the lower end opening 2b may be about 30 ° to 90 °, and a configuration that does not rotate may be used. If the rotation angle is zero or small, the support rod 10 can be omitted.

As the rotating mechanism 5, for example, the upper end opening 2a of the input pipe 2 may be rotatably attached to the lower end of the hopper 11 to provide a moving device such as a crane for moving the lower end opening 2b. With this moving device, the lower end opening 2b can be rotated to a desired position in the horizontal direction around the hopper 11.

Further, in this embodiment, the vertical movement mechanism 8 is used to change the vertical position of the lower end opening 2b of the input pipe 2 according to the position of the water bottom, and the earth and sand S is discharged from the lower end opening 2b at each changed position. can do. Therefore, the sediment S can be evenly deposited over a relatively wide area, which is advantageous for forming a flat shallow field.

When water W is injected together with the earth and sand S into the upper end opening 2a of the input pipe 2, it is advantageous to prevent the earth and sand S from being clogged in the input pipe 2. For example, the water W in the water area is sucked up by a pump or the like and put into the hopper 11.

After the loading of the earth and sand S at the position where the floating body 13 is moored is completed, the floating body 13 is moved to another position and moored, and the earth and sand S is similarly charged to the bottom of the water. By performing this work on the entire range of the target water area, the creation of shallow areas will be completed.

The embodiment of the earth and sand input device 1 illustrated in FIG. 7 differs from the previous embodiment only in the reflux pipe 3. In this embodiment, the input pipe 2 is inserted into the return pipe 3, and a double pipe is formed in which the input pipe 2 is an inner pipe and the return pipe 3 is an outer pipe. In this embodiment, the structure can be simplified, and the cross-sectional area of the recirculation pipe 3 (the cross-sectional area of the gap between the outer peripheral surface of the input pipe 2 and the inner peripheral surface of the recirculation pipe 3) can be easily increased. ..

1 Sediment loading device 2 Loading pipe 2a Upper end opening 2b Lower end opening 3 Recirculation pipe 3a Upper end opening 3b Lower end opening 4 Opening and closing lid 5 Rotating mechanism 6 Rotating plate 6a Recessed 7 Drive motor 8 Vertical movement mechanism 8a Winch 8b Wire 9 Support roller 10 Support Rod 11 Hopper 12 Belt conveyor 13 Floating body 13a Carrier 13b Engagement part S Sediment

Claims (12)

The injection pipe is installed so as to extend from the water to the water, a recirculation pipe is installed adjacent to the input pipe, the lower end opening of the recirculation pipe is arranged in the vicinity of the lower end opening of the input pipe, and the recirculation pipe is arranged. the interior communicates with the interior of the feeding pipe in position in the longitudinal direction middle of the feeding pipe, is set toward the lower end in the lateral direction said feeding pipe from the water by bending or inclined towards the bottom of the water, the An open / close lid that can be opened and closed is installed at the lower end opening of the input pipe.
Sediment is injected from the upper end opening of the input pipe, and the opening / closing lid is opened upward by the pressure of the earth and sand flowing inside the input pipe, and is located below the opening / closing lid in the opened state. The earth and sand are discharged from the lower end opening of the input pipe and deposited on the bottom of the water, and a part of the water flowing inside the input pipe toward the lower end opening is discharged from the vicinity of the lower end opening of the input pipe to the return pipe. A method for producing a shallow field, characterized in that a circulating flow is generated which circulates between the input pipe and the recirculation pipe by recirculating the inside of the input pipe through the recirculation pipe through the lower end opening of the pipe. The input pipe is installed so as to extend from the water to the water, and a recirculation pipe is installed adjacent to the input pipe, and the lower end opening of the recirculation pipe communicating with the inside of the input pipe is provided near the lower end opening of the input pipe. Is arranged, and the upper end opening of the recirculation pipe communicating with the inside of the input pipe is arranged at a position in the middle of the longitudinal direction of the input pipe, and the input pipe is bent or inclined from the water surface toward the bottom of the water to bend or incline the lower end thereof. The portion is set laterally, and the lower end opening of the recirculation pipe is arranged on the upper side surface of the input pipe at a position in the middle of the longitudinal direction near the lower end opening of the input pipe, and has a smaller diameter than the input pipe. The recirculation pipe extends along the input pipe on the outer surface of the input pipe.
Sediment is injected from the upper end opening of the input pipe, discharged from the lower end opening and deposited on the bottom of the water, and the earth and sand are injected from the upper end opening of the input pipe to recirculate the sediment in communication with the input pipe. The water level inside the input pipe is lowered from the upper end opening of the pipe, and the water existing inside the recirculation pipe is allowed to flow into the inside of the input pipe through the upper end opening of the recirculation pipe. A part of the water flowing through the inside of the pipe toward the lower end opening is returned to the inside of the input pipe from the vicinity of the lower end opening of the input pipe through the lower end opening of the recirculation pipe and then into the inside of the input pipe. A method for producing a shallow field, which comprises generating a circulating flow that circulates between a pipe and the recirculation pipe. An opening / closing lid that can be opened and closed is installed at the lower end opening of the input pipe, earth and sand are poured from the upper end opening of the input pipe, and the opening / closing lid is moved upward by pressing the earth and sand flowing inside the input pipe. The shallow manufacturing method according to claim 2, wherein the earth and sand are discharged from the lower end opening of the input pipe located below the opening / closing lid in the open state and deposited on the bottom of the water. The production of a shallow field according to any one of claims 1 to 3 , wherein the water depth from the water surface to the water bottom is 1 m or more and less than 5 m, and the lengths of the input pipe and the reflux pipe are set to be 1 m or more longer than the previous water depth. Method. The method for producing a shallow field according to any one of claims 1 to 4, wherein water is injected together with the earth and sand into the upper end opening of the input pipe. A throw-in pipe installed on a floating body and extending from the water to the water and a return pipe installed adjacent to the throw-in pipe are provided, and the lower end opening of the return pipe is arranged in the vicinity of the lower end opening of the throw-in pipe. The inside of the recirculation pipe communicates with the inside of the input pipe at a position in the middle of the longitudinal direction of the input pipe, and is installed in a circulation path formed by the input pipe and the recirculation pipe and at the lower end opening of the input pipe. With an openable / closable opening / closing lid , the input pipe is bent or inclined from the water surface toward the bottom of the water, and the lower end portion thereof is set laterally, and the upper end of the set input pipe is set. The opening / closing lid opens upward due to the pressure of the earth and sand introduced from the opening, and the earth and sand are discharged from the lower end opening of the input pipe located below the opening / closing lid in the opened state, and the earth and sand are discharged. Sediment characterized in that a part of the water flowing inside the input pipe toward the lower end opening circulates in the circulation path from the vicinity of the lower end opening of the input pipe through the lower end opening of the return pipe. Input device. The earth and sand injection device according to claim 6 , wherein the input pipe is inserted into the return pipe, and a double pipe having the input pipe as an inner pipe and the return pipe as an outer pipe is formed. A throw-in pipe installed on a floating body and extending from the water to the water and a return pipe installed adjacent to the throw-in pipe are provided, and the lower end opening of the return pipe is arranged in the vicinity of the lower end opening of the throw-in pipe. The inside of the return pipe communicates with the inside of the input pipe at a position in the middle of the longitudinal direction of the input pipe, and has a circulation path formed by the input pipe and the return pipe, and the input pipe is on the water. The lower end of the recirculation pipe is set laterally by bending or inclining toward the bottom of the water, and the lower end opening of the recirculation pipe is above the position in the middle of the longitudinal direction of the inlet pipe near the lower end opening of the inlet pipe. The recirculation pipe arranged on the side surface and having a diameter smaller than that of the input pipe extends to the outer surface of the input pipe along the input pipe, and is charged from the upper end opening of the set input pipe. The earth and sand are discharged from the lower end opening of the input pipe, and the earth and sand are injected from the upper end opening of the input pipe, so that the input pipe is more than the upper end opening of the recirculation pipe communicating with the input pipe. The water level inside is lowered, and the water existing inside the recirculation pipe flows into the inside of the input pipe through the upper end opening of the recirculation pipe, so that the inside of the input pipe is directed toward the lower end opening. A sediment injection device characterized in that a part of the flowing water circulates in the circulation path from the vicinity of the lower end opening of the input pipe through the lower end opening of the return pipe. It has an openable / closable opening / closing lid installed at the lower end opening of the input pipe, and the opening / closing lid is opened upward by pressing the earth and sand introduced from the upper end opening of the input pipe, and the opening / closing lid is opened. The earth and sand injection device according to claim 8, wherein the earth and sand are discharged from the lower end opening of the input pipe located below the opening / closing lid. The earth and sand injection device according to any one of claims 6 to 9, further comprising a rotation mechanism for rotating the lower end opening of the input pipe in the horizontal direction. The earth and sand injection device according to any one of claims 6 to 10, further comprising a vertical movement mechanism for moving the lower end opening of the input pipe up and down. The earth and sand loading device according to any one of claims 6 to 11, wherein the cross-sectional area of the reflux pipe is set to 80% to 100% with respect to the cross-sectional area of the charging pipe.

Images