JPH1060871A - Method of dam renewal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive the renewal of a dam by providing a temporary weir body inside a bank of a dam and removing water in the range covered with this temporary weir body, forming a through hole in the bank with an excavating device installed outside the bank of the dam and discharging deposits at the bottom of the dam together with water. SOLUTION: A temporary weir body 3 is provided inside a bank 2 of a dam 1, thereby forming an enclosure between the bank 2 and the temporary weir 3. The temporary weir body 3 forms a double wall 10 with a steel plate sheet pile where grout is filled up between these walls 10. The water in the range covered with this weir body 3 is excluded, thereby creating a dries state. On one hand, an excavating device 5 is installed outside the bank 2 of the dam 1, thereby forming a through hole 6 in the bank 2 by means of the excavating device 5. The deposits on the bottom of the dam and water are discharged from the through hole 6. It is, therefore, possible to discharge earth and sand deposited on the bottom of the dam and contrive the renewal of the dam and secure a stored amount of water even when the service of the dam 1 is turned impossible or the function of the dam is turned in a degraded state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dam renewal method in which a through hole is formed in a dam from the outside of the dam to discharge (discharge) sediment (sand) deposited on the bottom of the dam.

[0002]

2. Description of the Related Art As a sediment (mainly, sediment) accumulates at the bottom of a dam with the passage of years from the completion of the dam, the bottom of the dam gradually rises, and water is stored in the dam accordingly. The capacity of the water gradually decreases and loses its function as a dam. Therefore, in order to release the stored water and simultaneously discharge the sediment deposited at the bottom of the dam to the outside of the dam, a drain is provided at the dam when the dam is constructed, and the water is discharged regularly. Accordingly, a method of discharging sediment deposited on the bottom of the dam has been used.

[0003]

However, this method has a problem that only a few percent of the sediment can be released, ie, the upper part of the sediment.

On the other hand, in a dam having no old discharge port, the bottom of the dam gradually rises due to sediment accumulation, the capacity of water stored in the dam gradually decreases, and the dam loses its function. A number of situations have arisen where the aging dam has to be discarded.

[0005] In view of such circumstances, the present invention provides a method of renewing a dam that is retired as a function recovery dam by discharging sediment such as sediment deposited on the bottom of a dam that is aging and is unusable or has deteriorated in function. The purpose is to provide.

[0006]

In order to achieve the above object, a dam renewal method according to the first aspect of the present invention is to provide a temporary dam body inside a dam dam and form an enclosure between the dam and the dam dam. The water in the area surrounded by the temporary dam body is removed, and the area surrounded by the temporary dam body is set to the same state as in the atmosphere. On the other hand, a digging device is installed outside the dam dam, and the digging device attaches to the dam. A hole is formed, and the sediment at the bottom of the dam is discharged together with water from the through hole.

[0007] In the dam renewal method according to the second aspect of the present invention, the temporary weir is formed of sheet pile or steel pipe sheet pile.

According to a third aspect of the present invention, there is provided a dam renewal method, wherein the temporary weir forms a double wall with a sheet pile or a steel pipe sheet pile, and grout or sand is filled between the double walls. It is characterized by being configured.

Further, the dam renewal method according to the invention of claim 4 is characterized in that a gate which can be opened and closed is provided at an opening on the inflow side of the through hole.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a plan view showing an embodiment of the present invention, and FIG. 3 is a sectional view showing a completed state by the method of the present invention.

According to the dam renewal method of the present invention, the dam 1
A temporary dam 3 is provided inside the dam 2, an enclosure is formed between the dam 2, and water in a range 4 surrounded by the temporary dam 3 is removed, and a state similar to the atmosphere (dry state) On the other hand, a digging device 5 is installed outside the dam 2 of the dam 1, a through hole 6 is formed in the dam using the digging device 5, and the sediment 7 on the dam bottom 1 a is discharged from the through hole 6. It is characterized by being released together with.

In carrying out this dam renewal method, necessary investigations are first made on the depth of the dam 1, the state of accumulation of sediment 7 such as earth and sand, and the like. This is because it is necessary to determine where in the dam 2 the through hole is to be drilled, where the excavator 5 is to be installed, and the like.

For example, when the excavator 5 is installed,
In order to determine the installation position, the depth from the water surface 8 of the dam and the state of accumulation of the sediment 7 are measured, and the position of the dam 2 where the through hole 6 for discharging the earth and sand is determined. Further, the through-hole 6 may be inclined not only horizontally but also in order to improve the discharge of earth and sand. Therefore, the installation position of the excavator 5 is determined in consideration of how the through holes 6 are provided.

When the installation position of the excavator 5 is determined, a scaffold or the like is assembled at a corresponding position outside the bank 2 and the excavator 5 is installed. The excavator 5 may be a conventionally known excavator, and a horizontal excavator is particularly effective. As an example, an excavator used for a rock molding method and the like can be mentioned.

On the other hand, when drilling the through-hole 6, it is necessary to remove water from the inside of the bank 2 near the drilling arrival position and to keep the same state (dry state) as in the atmosphere.

Therefore, a temporary dam body 3 is constructed inside the dam 2 near the drilling position. The temporary dam body 3 forms an enclosure 4 between the dam 2 and the dam 4 so as to prevent water from flowing into the enclosure 4, thereby discharging the water in the enclosure 4. In addition, the inside of the bank 2 near the drilling position can be brought into the same state as in the atmosphere. The drainage in the enclosure 4 is performed using a drainage hole, a pump, and the like of the dam 2.

The construction of the temporary weir 3 is made of sheet pile, steel pipe sheet pile and the like. In the illustrated embodiment, sheet pile or steel pipe sheet pile 3
The double wall 10 is formed by a, and grout or sand is filled between the double walls 10, 10. A tie rod 11 may be provided between the double walls 10 to improve the strength, or a support frame 12 may be provided between the wall 10 and the dam 2.

The above embodiment is an example in which the water pressure of the water stored in the temporary weir body 3 is large.
If only a is sufficient, it may be formed by itself. That is, a sheet pile or a steel pipe sheet pile is installed and enclosed inside the dam 2 near the hole, and the water stored in the enclosure is drained. The illustrated embodiment is a case where a single reservoir or steel pipe sheet pile is hit only in a deep reservoir, a large reservoir, or the like, cannot withstand the water pressure of the reservoir,
For example, another row or sheet pile is struck inside the row of initially struck piles or pipe piles and the walls 10, 10 are struck.
In this example, the water between the walls 10 and 10 is drained, and the drained space is grouted to form a temporary weir 3 that can sufficiently withstand the water pressure of the reservoir.

In this way, the inside of the bank 2 near the drilling hole can be in the same state (dry state) as in the atmosphere, and a work space where the work can be safely performed is formed.

Thus, the excavator 5 drills the dam 2 toward the inside of the dam to form a through hole 6. At this time, since the inside of the dam 2 near the drilling hole is in the same state as the atmosphere, even if the drilling penetrates and an opening is formed inside the dam, the water does not flow out and the worker and Drilling rig 5
Safety can be ensured.

Incidentally, a plurality of through holes 6 are provided if even one is insufficient. FIG. 2 shows an example in which it is provided at three locations. In the case of providing a plurality of dams, it is effective to provide the temporary dam body 3 over the entire width inside the dam 2 as shown in FIG. As a matter of course, as shown in FIG.

Next, as shown in FIGS. 2 and 3, a gate 9 is provided in each of the inside openings of the through holes 6 on the water storage side.
Is provided. This gate 9 is connected to one end of the deposit 7 through the through hole 6.
When water is discharged with water, the opening is closed. Also,
If sediment deposits again over time, they can be reopened and drained again.

The gate 9 is provided with a guide (not shown) on the wall surface of the bank 2 and moves (elevates) along the guide.
A cable 14 of a winch 13 is connected to the gate 9 so that the gate 9 can be moved up and down. Therefore, the gate 9 can be moved up and down by the winch 13 to open and close the opening. Instead of the gate 9, the water may be stopped by a steel pipe pile.

When the installation of the gate 9 is completed, the temporary dam body 3 is finally removed and completed. In carrying out the present method, it goes without saying that a scaffold is formed to improve workability and work safety.

Further, when sediment (mainly earth and sand) accumulates on the bottom of the dam, the dam may be renewed by further adding a dam on the dam and raising the dam or embankment around the dam.

[0026]

As described above in detail, according to the present invention, a temporary dam is provided inside a dam dam, an enclosure is formed between the dam and the dam, and water in an area surrounded by the temporary dam is formed. The surrounding area is set in the same state as the atmosphere, while a digging device is installed outside the dam embankment, and the digging device forms a through hole in the dam, and the bottom of the dam is deposited from the through hole. As the material is released together with water, sediment such as sediment accumulates on the bottom of the dam and releases sediment such as sediment deposited on the bottom of the dam even if the dam becomes unusable or degraded. Then, the dam can be renewed and the required amount of water can be secured.

In particular, since the present invention can be applied to an old dam having no discharge port and can be renewed, the economic effect of renewing an old dam is very large.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a completed state by the method of the present invention.

FIG. 4 is a plan view showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 dam 2 dam 3 temporary dam 3a sheet pile or steel pipe sheet pile 4 area surrounded by dam and temporary dam 5 excavator 6 through hole 7 sediment 9 gate 10 wall 13 winch

Claims (4)

[Claims] 1. A temporary dam body is provided inside a dam of a dam, an enclosure is formed between the dam and the dam, water in an area surrounded by the temporary dam is removed, and the enclosed area is exposed to the atmosphere. On the other hand, an excavator is installed outside the dam dam, a through hole is formed in the dam by the excavator, and the sediment at the bottom of the dam is discharged from the through hole together with water. Dam renewal method. 2. The method according to claim 1, wherein the temporary dam body is formed of sheet pile or steel pipe sheet pile. 3. The temporary weir body is formed by forming a double wall with sheet pile or steel pipe sheet pile, and filling grout or sand between the double wall. 1
Renewal method of dam described. 4. The method for renewing a dam according to claim 1, wherein a gate that can be opened and closed is provided at an opening on the inflow side of the through hole.