JP5853646B2 - Temporary deadline structure of dam body - Google Patents

Description

  The present invention relates to a temporary closing structure of a dam dam body, and specifically relates to a technique of a temporary closing structure that can be constructed using a smaller crane than conventional ones.

  Through holes in the dam body of the existing dam for the purpose of securing a sediment discharge path on the upstream side of the dam body, a new water discharge path for the purpose of increasing flood control capacity, or a small hydroelectric generator installation area The number of cases of building is increasing. Conventionally, when constructing a through-hole in an existing dam body, a large-scale temporary cut-off work has been carried out to reach the bottom of the water upstream of the dam body, and the inside of the cut-off structure has been dried up to drill the through-hole. It was. However, such a method has a problem that the temporary deadline structure becomes large and the construction period and construction cost increase. Therefore, as a technology that enables temporary closing of dam water areas at a small scale and low cost, for example, a temporary closing structure (Patent Document 1) in which a spherical water blocking wall is attached to the surface of the dam dam body is proposed. Has been.

JP 2004-263380 A

  When attaching or removing the hemispherical water blocking wall in the conventional temporary closing structure to or from the dam dam body, work such as hanging or lifting the hemispherical water blocking wall with a crane installed on the dam body Is required. On the other hand, since the hemispherical water blocking wall is a heavy object, the crane for performing the above-described suspension and lifting becomes huge. Therefore, the problem that the effort which installs and operates a huge crane in the limited area | region on a bank body, and the cost accompanying arrangement and use of such a crane tend to increase.

  Therefore, an object of the present invention is to provide a technology of a temporary closing structure that can be constructed using a smaller crane than conventional ones.

The temporary closing structure of the dam dam body of the present invention that solves the above-mentioned problem is a dome-shaped temporary closing structure used when constructing a through hole in an existing dam dam body, and a plurality of parts are watertight to each other via a water stop material. A dam dam body temporary cut-off structure that is connected and separably connected to each other, and each of the plurality of parts is ribbed at a location corresponding to a dividing surface of the temporary cut-off structure. The ribs of the adjacent parts are connected to each other so as to be separable by being tightened with a bolt in a state of sandwiching the water blocking material .

  According to such a temporary closing structure, for example, the temporary closing structure is constructed by sequentially suspending and temporarily fixing each part from the lower part of the temporary closing structure to a predetermined position in water, and connecting the parts in water. Can be configured. Alternatively, the provisional deadline structure can be removed by sequentially disconnecting the parts from the upper part of the temporary deadline structure installed in water and lifting the parts. In such a case, even if the dome-shaped temporary closing structure itself is quite heavy, the object to be hung or lifted during construction is a separate part of the temporary closing structure, and it is necessary to use a huge crane. There is no. For this reason, it is possible to reduce the trouble of installing and operating a huge crane in a limited area on the dam body, and the costs associated with the arrangement and use of such a crane. Therefore, according to the present invention, it is possible to provide a temporary closing structure that can be constructed using a smaller crane than the conventional one.

In addition, the present invention is a dome-shaped temporary closing structure used when constructing a through hole in an existing dam dam body, and a plurality of parts are connected to each other in a watertight manner through a waterstop material. a is a provisional deadline structure of the dam body are detachably connected to each other, a plurality of parts, Ru der obtained by dividing the provisional deadline structure with an aerial weight of more buoyancy caused the temporary shut-off structure in water It is characterized by that . In the temporary closing structure constructed by connecting each part in water, drainage of the inside air generates a large buoyancy, but because the air weight of the temporary closing structure can resist this buoyancy, it has a special buoyancy. There is no need to take measures, and an efficient temporary closing structure can be constructed.

  Moreover, the parts in the above-mentioned temporary closing structure of the dam dam body may be obtained by dividing the temporary closing structure radially around the top of the dome shape.

  ADVANTAGE OF THE INVENTION According to this invention, the temporary closing structure which can make the crane utilized at the time of construction smaller than before can be provided.

It is a general view which shows the structural example of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 1 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 2 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 3 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 4 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 5 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 6 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 7 of the temporary closing structure in this embodiment. It is a figure which shows the construction procedure 8 of the temporary closing structure in this embodiment.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall view showing a structural example of a temporary closing structure of a dam dam body in the present embodiment. The temporary closing structure 100 in the present embodiment is a temporary closing structure on the upstream side of the dam body used in the construction of the through hole 2 such as a sand pit in the dam body 1 of the existing dam. As shown in FIG. 1, the temporary cutoff structure 100 of the present embodiment has a dome shape that forms a semi-elliptical structure whose cross section is convex on the upstream side of the dam dam body. The temporary closing structure 100 includes a plurality of parts 30 that are watertightly connected via a water stop material 35. The part 30 illustrated in FIG. 1 includes parts 30a, 30b, 30c, and 30d obtained by dividing the temporary cutoff structure 100 into four parts centering on the dome-shaped apex, and each part 30 corresponds to a split surface of the temporary cutoff structure 100. The location is provided with abutment ribs 36. The abutment ribs 36 of each part 30 are brought into contact with each other with the water blocking material 35 interposed therebetween, and bolts 34 are inserted into bolt holes 33 (see FIG. 2 and the like) of the respective abutment ribs 36 communicated at the time of the abutment. The connection between the parts 30 is achieved by fastening. The parts 30 thus connected are also released by releasing the bolt fastening that fixes the contact ribs 36 of the parts. That is, the parts 30 are connected to each other in a separable manner.

  Further, the opening 21 of the temporary cutoff structure 100 surrounds the planned opening position 4 a of the through hole 2. An air supply valve 27 and a manhole 28 are provided at the upper outer periphery of the temporary cutoff structure 100, and a drainage valve 29 is provided at the lower outer periphery.

  The air supply valve 27 is a valve that is connected to an air supply device on the bank 2 via an appropriate air supply path and guides air to the inner space 25 of the temporary cutoff structure 100. The manhole 28 is an opening / closing port serving as an entrance / exit of a worker who performs work in the inner space 25 of the temporary closing structure 100. The manhole 28 includes a valve (not shown), and can be opened and closed between the inner space 25 and the outside of the manhole. The drain valve 29 is a valve for draining water from the inner space 25 of the temporary closing structure 100 to the outside.

  Further, the temporary cutoff structure 100 is brought into contact with the dam dam body upstream surface 3 at the skirt portion 32. The skirt portion 32 is obtained by extending the peripheral edge of the opening 21 of the temporary closing structure 100 by a predetermined width along the dam dam body upstream surface 3, and abuts the dam dam body upstream surface 3 via the water blocking material 7. The skirt portion 32 is provided with an anchor driving hole, and the anchor is driven from the anchor driving hole toward the upstream surface 3 of the dam dam body. It may be temporarily fixed to.

  Note that the part 30 described above may be obtained by dividing a temporary cutoff structure having an aerial weight greater than the buoyancy generated in the temporary cutoff structure 100 in water. In the temporary closing structure 100 in which the parts 30 are connected in water, if the inner air 25 is drained, a large buoyancy is generated. However, the air weight of the temporary closing structure 100 can resist this buoyancy. Therefore, it is not necessary to take special measures for buoyancy, and an efficient temporary closing structure can be constructed.

  Hereinafter, the procedure of construction of the temporary closing structure 100 and construction of the through hole 2 of the present embodiment will be described in detail. 2-9 is a figure which shows each construction procedure 1-8 of the temporary closing structure in this embodiment, respectively. First, as shown in FIG. 2, the temporary gantry 50 is installed on the ground 5 at the bottom of the water area of the dam dam body 1, and the lower part of the temporary cutoff structure 10 among the parts 30 forming the temporary cutoff structure 100 is The formed parts 30c and 30d are sequentially suspended on the temporary gantry 50 (procedure 1). The temporary gantry 50 is a temporary structure that is installed in advance on the ground 5 at the bottom of the water body side of the levee body 1. The parts 30 that are suspended from above are received on the base 51, and various parts of the corresponding parts 30 are received. It has an appropriate structure for gripping and fixing. Further, the height from the bottom of the table 51 in the temporary gantry 50 is set in advance so that the opening 21 of the temporary closing structure 100 configured by connecting the parts 30 and the like surrounds the planned opening position 4a of the through hole 2 described above. ing.

  Further, the parts 30c and 30d suspended on the table 51 (in FIG. 2, only the hanging state of the part 30c is shown as an example) are brought into contact with each other through the water stop material 35. And the bolts 34 are connected to each other. The fastening operation of the bolt 34 is performed by a diver disposed in the water.

  Following the procedure 1, as shown in FIG. 3, the parts 30a and 30b forming the upper part of the temporary closing structure 10 are sequentially suspended on the temporary gantry 50, and the suspended parts 30a and 30b (in FIG. 3, as an example) Only the hanging state of the part 30 b is shown) is connected to each other by contact between the contact ribs 36 via the water stop material 35 and fastening by the bolt 34. The part 30a is the part 30d of the parts 30c and 30d previously connected to the table 51, and the part 30b is the part 30c and 30d of the parts 30c and 30d previously connected to the table 51. It connects with the part 30c similarly to the above. In addition, the temporary closing structure 100 assembled in this way directs the opening 21 toward the dam dam body 1 and abuts the dam dam body upstream surface 3 through the water blocking material 7.

  Subsequently, as shown in FIG. 4, the manhole pipe 8 is suspended from the dam body by a crane 81 and connected to the manhole 28 of the temporary closing structure 100, and another manhole is connected to the upper end of the manhole pipe 8 connected to the manhole 28. The tubes 8 are sequentially connected (procedure 3). In installing the manhole tube 8, a work table ship 40 is floated in the water area upstream of the dam body, an operator is placed, the manhole tube 8 suspended by the crane 81 is positioned, the manhole 28 and the manhole tube 8 are connected, In addition, the manhole tube 8 is connected to each other. The manhole pipe 8 is temporarily fixed to the dam body upstream surface 3 with an appropriate tipping prevention material 9 such as a steel bar.

  Next, as shown in FIG. 5, the air supply hose 42 is extended from the pump 41 installed on the work table ship 40 and connected to the air supply valve 27 of the temporary cutoff structure 100, so that the inner space 25 of the temporary cutoff structure 100 is obtained. The supply of pressurized air to is started (procedure 4). At the same time, the drain valve 29 of the temporary closing structure 100 is opened, and the water existing in the inner space 25 of the temporary closing structure 100 is discharged along with the air filling by the above-mentioned supply air, and the inner space 25 is brought into a dry state To do. When air bubbles start to be ejected from the drain valve 29 of the temporary closing structure 100 during the above-described supply of pressurized air, it means that the drainage valve 29 and the air supply valve 27 are completely drained. Is closed, the valve of the manhole 28 is opened, the pressurized air is gradually released, and the inner space 25 is set to atmospheric pressure. Thus, the inner space 25 becomes atmospheric pressure, and the temporary cutoff structure 100 is pressed against the upstream surface 3 of the bank body by water pressure. When draining the water in the inner space 25, a submersible pump set in advance in the inner space 25 is operated with the above-described air supply valve 27 and drain valve 29 closed, and the upper end of the manhole pipe 8 is operated. Alternatively, a method of draining water may be employed.

  In addition, it is preferable that the temporary cutoff structure 100 is designed in advance so that the buoyancy generated when the inner space 25 of the temporary cutoff structure 100 is drained is equal to or less than the weight of the temporary cutoff structure 100 in the air. For example, since the applicants have obtained the knowledge that a buoyancy of approximately 18000 kN is generated in the temporary cutoff structure 100 when an attempt is made to install the temporary cutoff structure 100 having an opening with a diameter of 10000 mm at a water depth of 17 m. The temporary closing structure 100 is designed in advance so as to have an air weight that can resist buoyancy. Even if the temporary deadline structure 100 is required to have an aerial weight that can resist buoyancy, the parts to be suspended and lifted by the crane are the parts 30 obtained by dividing the temporary deadline structure 100, and a huge crane is not required for construction. .

  The dome-shaped temporary cutoff structure 100 is thus installed at the position of the upstream opening 4 in the through hole 2 (expected opening position 4a), and a working space is secured in the inner space 25 of the temporary cutoff structure 100, and then, FIG. As shown, a management corridor 43 is provided above the uppermost manhole tube 8 among the connected manhole tubes 8, and workers who have moved from the upper part of the bank 1 are in contact with the management corridor 43, the manhole tube 8, and the manhole. 28 enters the inner space 25 of the temporary cutoff structure 100 (procedure 5). The worker who enters the inner space 25 confirms that the inner space 25 is in a drained state. On the other hand, it is assumed that an appropriate excavator such as a loader 85 excavates the through hole 2 from the downstream side of the bank body. After confirming the drainage completion state of the inner space 25, the loader 85 performs excavation of a portion left between the inner space 25 of the temporary closing structure 100 and the drilled through hole 2.

  When this excavation is completed and the inner space 25 and the through hole 2 of the temporary closing structure 100 are penetrated, as shown in FIG. 7, the installation of the closing gate door body door 47 and the bell mouth 46 and the air pipe 45 are performed. (Procedure 6). In this case, it is suspended in the water together with any of the parts 30, and the closed gate door body door 47 and the bell mouth 46 previously placed in the inner space 25 of the temporary closing structure 100 are installed on the dam body 1. Further, the discharge pipe 48 is carried in from the downstream of the bank body in the through hole 2, and the discharge pipe 48 is connected to the closed gate door body 49 and the bell mouth 46. Further, the closed gate door body 49 is connected to the door 47 for the closed gate door body and the bell mouth 46.

  After this connection is completed, concrete is placed in a predetermined region such as a gap between the discharge pipe 48 and the inner wall of the through hole 2. In addition, the worker who has been working in the inner space 25 of the temporary closing structure 100 is made to leave on the work table boat 40 on the water or the management corridor 43 through the manhole pipe 8.

  Subsequently, the air supply valve 27 and the drain valve 29 are opened, and the inner space 25 of the temporary closing structure 100 is filled with water. Further, as shown in FIG. 8, after the manhole tube 8 connected to the manhole 28 is sequentially removed and the upper part 30a, 30b and the lower part 30c, 30d in the temporary closing structure 100 are disconnected. The upper parts 30a and 30b are lifted by the crane 80 and removed (procedure 7).

  Next, as shown in FIG. 9, after the temporary fixing between the lower parts 30c and 30d and the temporary construction base 50 in the temporary closing structure 100 is released, the lower parts 30c and 30d are lifted by the crane 80 and removed ( Procedure 8). These parts 30c, 30d may be lifted after being disconnected, or depending on the ability of the crane 80, they may be lifted as they are without being disconnected. After the lower parts 30c and 30d are removed, the temporary gantry 50 is removed, and the process ends.

  In addition, in the above-described embodiment, the construction mode in which all the parts 30 and the like are individually lifted or hung is exemplified, but among a plurality of parts, lifting and hanging are performed in a state where a group of parts are connected. Also good. Alternatively, when the temporary deadline structure 100 is installed, the temporary deadline structure 100 assembled on the dam body 1 is suspended in water, and when the temporary deadline structure 100 is removed, the temporary deadline structure 100 is appropriately divided into parts 30. Then, a construction form such as lifting may be adopted. In any case, the construction form can be flexibly selected according to the construction conditions including the ability of the crane arranged on the bank body 1.

  Thus, according to the present embodiment, it is possible to provide a temporary closing structure that can be constructed using a smaller crane than conventional ones.

  Although the embodiment of the present invention has been specifically described based on the embodiment, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Bank body 2 Through-hole 2a Inner wall surface 3 Through-hole upstream face 4 Opening 4a Opening planned position 5 Through hole 7 Water stop material 21 Opening 24 Outer peripheral surface 25 Inner air 27 Supply valve 28 Manhole 29 Drain valve 30 Parts 32 Skirt portion 33 Bolt hole 34 Bolt 35 Water stop material 36 Abutment rib 45 Air pipe 46 Bell mouth 47 Closed gate door body door 48 Discharge pipe 49 Closed gate door body 50 Temporary gantry 100 Temporary cutoff structure

Claims (3)

It is a dome-shaped temporary closing structure used when constructing a through hole in an existing dam dam body. A plurality of parts are connected to each other in a watertight manner through a water blocking material, and the plurality of parts are connected to each other in a separable manner. It is a temporary deadline structure of the dam dam body,
Each of the plurality of parts is provided with ribs at locations corresponding to the dividing surface of the temporary closing structure, and the ribs of the adjacent parts are fastened with bolts while sandwiching the water-stopping material. A dam dam body temporary cut-off structure characterized by being separably connected . It is a dome-shaped temporary closing structure used when constructing a through hole in an existing dam dam body. A plurality of parts are connected to each other in a watertight manner through a water blocking material, and the plurality of parts are connected to each other in a separable manner. A dam dam body temporary cut-off structure, wherein the plurality of parts are obtained by dividing a temporary cut-off structure having an aerial weight greater than a buoyancy generated in the temporary cut-off structure in water. The deadline structure of the embankment. In Claim 1 or 2, The above-mentioned parts are the above-mentioned temporary cutoff structure divided radially from the top of the above-mentioned dome shape.

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