JP2010216125A - Method for constructing penetrating pit in existing dam body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inexpensively constructing a penetrating pit in an existing dam body in a short period. <P>SOLUTION: A gate 4 is housed inside a cofferdam 1, which is composed of a shell body with an opening 1a, in such a manner as to be attachable/detachable by a fixing means 6. The cofferdam 1 is lowered in a suspended state by a crane etc.; and the opening 1a of the cofferdam 1 is arranged in the state of contact with the dam body 9. Water in the cofferdam 1 is discharged by a lifting pump etc. via a pipe 7, so that the opening 1a can be brought into close contact with the dam body 9. Subsequently, a water passage 2 passing through the dam body 9 is constructed from a downstream side; and the inside of the cofferdam 1 and the downstream side of the dam body 9 communicate with each other. The gate 4 housed in the cofferdam 1 in advance is mounted in a predetermined position in the dam body 9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for constructing a through-hole such as a water passage in an existing dam dam body.

  Conventionally, when constructing a through-hole such as a waterway in an existing dam dam body, after installing a steel pipe sheet pile etc. as a large-scale temporary deadline that continues to the bottom of the water on the upstream side of the dam dam body, The tunnel construction part was dried up and the tunnel was excavated, and a door body and a screen (hereinafter, the door body and the screen are referred to as a gate) were attached to the upstream side of the tunnel. However, this method has a problem that temporary construction becomes large and the construction period and construction cost increase.

  Therefore, for example, Patent Document 1 describes a method for constructing a through hole that rationalizes temporary construction. In the method described in this document, after installing the temporary deadline communicating with the surface of the water by the shaft at the planned opening position of the upstream wellhead, the water in the temporary deadline is drained and dried up, and the gate is installed therein. Doing work. In this method, the gate that has been divided so that it can be inserted through the shaft is suspended by a crane several times and loaded into the temporary deadline, and the divided gate is assembled within the temporary deadline, and then placed at the planned opening of the wellhead. Install.

Showa 64-58709

  However, in the method described in Patent Document 1, the carrying-in work for carrying in the divided gates and the assembling work for assembling the gates must be performed in a narrow place within the temporary deadline, and the construction period is also long. There was a point. In addition, a lifting equipment such as a crane must be used for carrying-in work and assembly work.

  Then, this invention is made | formed in view of said problem, and it aims at providing the method of constructing a through-hole in the existing dam dam body in a short period of time and cheaply.

The present invention is a method for constructing a through hole in an existing dam body,
Temporary deadline installation step for accommodating a gate for opening and closing a wellhead on the upstream side of the through-hole and installing a temporary deadline made of a shell body having an opening so that the opening closely contacts the dam dam body When,
A draining step for draining water in the temporary deadline;
A through-hole construction step of constructing the through-hole that penetrates the dam dam body from the downstream side of the dam dam body into the temporary deadline;
A gate installation step of attaching the gate to a wellhead upstream of the through-hole in the temporary deadline;
Removing the temporary deadline from the dam dam body.

  According to the present invention, since the temporary cutoff with the gate accommodated therein is installed at the planned opening position of the through-hole, there is no need for a temporary steel pipe sheet pile for large-scale cutoff that has been installed on the upstream side of the conventional dam dam body. It becomes. In addition, since there is no carry-in work for bringing the gate into the temporary deadline or assembly work for assembling the gate within the temporary deadline, the shaft attached to the temporary deadline described in the prior art document becomes unnecessary, and the temporary deadline is It can be simple. Furthermore, since no carry-in work or assembly work is performed, work in a confined space within the temporary deadline can be reduced, and lifting equipment such as a crane is not required.

  According to the present invention, a through-hole can be constructed in an existing dam dam body in a short period of time and at a low cost.

It is a vertical sectional view showing a temporary deadline according to an embodiment of the present invention. It is a front view which shows the state which attached the temporary deadline to the dam dam body. It is a side view which shows the state which attached the temporary deadline to the dam dam body. It is a side view which shows the installation procedure which installs a gate in a water inlet. It is a side view which shows the installation procedure which installs a gate in a water inlet. It is a side view which shows the installation procedure which installs a gate in a water inlet. It is a front view which shows the state which installed the gate in the water inlet.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case will be described in which a water passage that is a through-hole is constructed in an existing dam dam body, and a gate is installed at a water intake that is a wellhead on the upstream side of the water passage.

  FIG. 1 is a vertical sectional view showing a temporary cutoff 1 according to an embodiment of the present invention. 2 and 3 are a front view and a side view, respectively, showing a state in which the temporary cutoff 1 is attached to the dam dam body 9.

  As shown in FIGS. 1 to 3, the temporary deadline 1 has a hollow cylindrical shape in which one bottom surface (the bottom surface on the right side in FIG. 1) is open (hereinafter referred to as an opening 1 a) and the other bottom surface is closed. In addition, a door body 4 a and a screen 4 b (hereinafter referred to as a gate 4) attached to the water intake 3 of the water passage 2 are accommodated by the fixing means 6 so as to be detachable. In addition, the state which attached the gate 4 to the water inlet 3 is shown in FIG.

  A pipe 7 for extracting water in the temporary cutoff 1 is connected to the upper end of the temporary cutoff 1. The length of the pipe 7 is adjusted so that the upper end of the pipe 7 exists above the surface of the dam lake when the provisional deadline 1 is installed at the planned opening of the water inlet 3. The pipe 7 does not have to be a straight cylindrical shape, and may be a hose shape as long as it can withstand suction during draining (described later) in the temporary cutoff 1.

  Further, a water stop material 8 is attached to the peripheral end portion of the opening 1 a of the temporary cutoff 1. As the water stop material 8, for example, butyl rubber can be used.

  4-6 is a side view which shows the installation procedure which installs the gate 4 in the water inlet 3. FIG. FIG. 7 is a front view showing a state where the gate 4 is installed in the water inlet 3.

First, as shown in FIG. 1, the gate 4 is attached to the inside of the temporary cutoff 1 by the fixing means 6.
Next, as shown in FIG. 3, the temporary deadline 1 in which the gate 4 is housed is suspended by a crane or the like to the planned opening position of the water intake 3 of the dam dam body 9, and the opening 1a of the temporary deadline 1 is It arrange | positions so that the dam body 9 may be touched.

Then, the water in the temporary cutoff 1 is pumped through the pipe 7 by a pumping pump or the like and drained outside the temporary cutoff 1. Thus, the opening 1a of the temporary deadline 1 is pressed against the dam body 9 due to the pressure difference between the temporary deadline 1 and the dam lake generated by discharging the water in the temporary deadline 1. At that time, when the water stop material 8 attached to the peripheral edge of the opening 1 a of the temporary cutoff 1 is in close contact with the dam dam body 9, it is possible to prevent water from flowing into the temporary cutoff 1. In addition, when the temporary deadline 1 is heavy and it falls off only by making it contact | adhere by water pressure, it fixes to the dam dam body 9 with an anchor etc.
When the water in the temporary deadline 1 is completely discharged, the drainage by the pump is stopped.

  Next, as shown in FIG. 4, a water passage 2 that penetrates the dam dam body 9 from the downstream side of the dam dam body 9 toward the temporary deadline 1 is constructed to Communicate with the downstream side.

  By using this water passage 2, materials and equipment used for mounting the gate 4 are carried into the temporary deadline 1. In the present embodiment, for example, a base 10 for supporting the gate 4, a guide material 11 and a jack 12 for drawing the gate 4 into a predetermined installation location, and other tools necessary for work are carried in as materials and equipment. To do.

  Next, as shown in FIG. 5, the gantry 10 carried into the provisional deadline 1 is disposed so as to contact the lower end surface of the gate 4, and is fixed to the dam dam body 9 with anchor bolts 13. Since the friction reducing material 14 is attached to the upper surface of the gantry 10, the gate 4 can be easily moved along the upper surface. As the friction reducing material 14, for example, Teflon can be used.

  Further, the rod-shaped guide material 11 is fixed to the dam dam body 9 through the gate 4. And the jack 12 for moving the gate 4 to the dam dam body 9 side is attached to the front-end | tip part of the guide material 11. FIG. The jack 12 is used to pull the gate 4 into the dam dam body 9 by applying a reaction force to the guide material 11 fixed to the dam dam body 9. As the guide material 11, for example, a PC steel rod can be used.

  Next, the gate 4 is removed from the fixing means 6 and the jack 12 is extended to move the gate 4 to the dam dam body 9 side, so that the gate 4 is moved to the dam dam body 9 as shown in FIGS. Fix in place.

  After fixing the gate 4, the jack 12, the portion of the guide material 11 that protrudes outward from the gate 4 and the mount 10 are removed.

  Finally, water is poured into the temporary cutoff 1 through the pipe 7 to fill it, and the temporary cutoff 1 is removed from the dam dam body 9. By filling the temporary deadline 1 with water, there is no difference in water pressure between the temporary deadline 1 and the dam lake, so the temporary deadline 1 can be easily removed. The temporary deadline 1 is collected by lifting it with a crane or the like.

  According to the construction method of the water passage 2 in the present embodiment described above, since the gate 4 is accommodated in the temporary deadline 1 in advance, the carrying-in work for bringing the gate 4 into the temporary deadline 1 or the temporary deadline 1 As a result, the assembly work for assembling the gate 4 becomes unnecessary, so that the work in a narrow space can be reduced and the construction period can be shortened. Moreover, the installation operation | work of the gate 4 can be implemented, without using the crane conventionally required for these carrying-in operations and assembly operations.

  In addition, by using the water passage 2, it becomes easy to carry the materials and equipment for attaching the gate 4 to the dam body 9 into the temporary cutoff 1. Therefore, it is possible to eliminate the need for a shaft that has been conventionally used for carrying in materials and equipment. However, a shaft may be provided, and materials and equipment may be carried through the shaft.

  Further, the provisional deadline 1 can be obtained at a low cost because it is easy to manufacture by adopting a hollow cylindrical shape.

  In addition, the temporary deadline 1 may be, for example, a hollow hemispherical shape, and in this case, since the water pressure is received by the compressive force, the thickness of the member can be reduced. Moreover, the thing of the semi-cylinder shape formed by cut | disconnecting a cylinder to a longitudinal direction and a hollow rectangular parallelepiped shape may be sufficient. And it is not limited to the temporary cut-off 1 made from steel, For example, it is good also as a product made from a concrete precast. In short, the shape of the temporary cutoff 1 is not limited as long as it is strong enough not to be crushed by water pressure.

  In addition, in this embodiment, although the case where the water channel 2 was built in the dam dam body 9 was demonstrated, it is not limited to this, If it is a penetration mine penetrating the dam dam body 9, it is applicable. For example, the present invention can be applied to a case where a discharge mine for discharging sedimentary soil is constructed.

DESCRIPTION OF SYMBOLS 1 Temporary deadline 1a Opening part 2 Water flow path 3 Water intake port 4 Gate 4a Door body 4b Screen 6 Fixing means 7 Pipe 8 Water stop material 9 Dam dam body 10 Base 11 Guide material 12 Jack 13 Anchor bolt 14 Friction reduction material

Claims (1)

In the method of constructing a through-hole in an existing dam body,
Temporary deadline installation step for accommodating a gate for opening and closing a wellhead on the upstream side of the through-hole and installing a temporary deadline made of a shell body having an opening so that the opening closely contacts the dam dam body When,
A draining step for draining water in the temporary deadline;
A through-hole construction step of constructing the through-hole that penetrates the dam dam body from the downstream side of the dam dam body into the temporary deadline;
A gate installation step of attaching the gate to a wellhead upstream of the through-hole in the temporary deadline;
Removing the temporary deadline from the dam dam body, and a method for constructing a through-hole in an existing dam dam body.

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