JPH0868039A - Concrete dam and construction method thereof - Google Patents

Abstract

PURPOSE: To rapidly and safely construct a dam and obtain a high quality dam, by erecting respective dam surface layers by use of a number of precast boards in both up and don stream sides in the construction area of the dam and placing concrete between the dam surface layers. CONSTITUTION: This construction method is constituted of a dam body 20 made of concrete 11 and dam surfaces 10 formed respectively by a number of precast boards 1 on the upstream side and the downstream side of the dam body 20. In this case, a space S1 for placing concrete is formed in the inside by precast boards 1. The space S1 is filled with left-in-place-concrete with the precast boards 1. Moreover, a plurality of precast boards 1 are laid on the concrete 11 already placed on respective upper end of precast boards 1 arranged on the up and don stream sides of the construction area Sd. And concrete 11 is placed in the next concrete space S1. In this way, such processes are repeated to construct a bank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete dam which is formed mainly of concrete across rivers and valleys and stores river water or runoff in the upstream, and a construction method thereof, and particularly to quick, safe, The present invention also relates to a concrete dam that enables high-quality construction and a construction method thereof.

[0002]

2. Description of the Related Art Conventionally, in the construction of concrete dams, the dam construction area is divided into blocks of about 15 m in the left and right bank direction, and formworks are installed on the upstream and downstream sides of the blocks.
Concrete is poured into each of the blocks so that concrete is sequentially placed in each block, and concrete is placed in the same manner as above on the already placed concrete. In addition, in the case of the RCD method that enables speedy construction of concrete dams,
As shown in 4, the formwork 1 installed on the upstream side and the downstream side
During 01, the North Lamp super-hard concrete 102 with reduced cement content is transported by the dump truck 103,
Spread it with a bulldozer 104, level it with a vibrating roller 105,
The vibrodozer 106 is used for compaction, and the horizontal joint 107 for preventing cracks is inserted by the vibration jointing machine 108.

In any case, in the conventional construction of a concrete dam, the formwork 101 is installed so as to form the concrete placing space S11 on the upstream side and the downstream side of the dam construction area, and the formwork 101 is formed. After the concrete 102 is poured into the concrete placing space S11 and the concrete 102 is hardened, the form 101 is moved upward and the upstream side of the bank 110 formed by the already placed concrete 102 and Installed on the downstream side, the next concrete placing space S is placed on the already placed concrete 102.
11 is formed, and the concrete 102 is launched in such a manner that the concrete is placed in the concrete placing space S11, and the dam is constructed. As the mold 101 used at this time, a large frame 101 formed by assembling a small steel mold having a width of 50 cm and a length of 150 cm is usually used, but in recent years, as shown in FIG. A so-called automatic formwork 120, which is a formwork that moves while anchoring the bank 110, is also used.

The outline of the automatic form 120 will be described below.
A working scaffold or the like is formed, and a self-propelled frame 121 detachably provided on the bank 110 is provided.
21 is provided with a self-propelling device 122 having a boom 122a that is vertically expandable and contractible. The upper end of the boom 122a is attachable to and detachable from the upper end of the form 123 provided on the upstream side or the downstream side of the bank 110, and the form 123 is provided with a plurality of traverse rails 124 extending in the left-right bank direction. ing. Further, the self-propelling device 122 includes a traverse rail 124.
A traversing device 125 is provided which is movable along.
Therefore, by attaching the upper end of the boom 122a to the form 123, attaching the self-raising frame 121 to the bank 110, and extending the boom 122a, the form 123 can be moved upward. Moreover, after attaching the form 123 to the bank 110, the self-climbing frame 121 can be pulled upward by removing the self-climbing frame 121 from the dam 110 and retracting the boom 122a. Therefore, the automatic mold 120 is movable in the vertical direction together with the mold 123. In addition, the automatic form 120
The self-climbing frame 121 is removed from the bank 110, the upper end of the boom 122a is removed from the form 123, and the traverse device 1
When 25 is mounted on the traverse rail 124 provided on the form 123, the traverse device 125 allows the traverse rail 124 to move in the left and right bank directions. Therefore, along the rails 124, it is possible to transfer to the adjacent molds 123 in the left and right bank direction, and thus all the molds 123 that are continuously provided in the left and right bank direction can be moved upward.

[0005]

However, in the construction of a conventional concrete dam, the following (a), (b),
It has a problem like (C). (B) Since large-scale work such as installing, removing, moving, and dismantling the formwork is required, it is difficult to further speed up the construction. (B) Because large-scale work at high places is required, such as work for attaching the formwork to the upstream and downstream sides of the dam body formed of already cast concrete, and work for removing it for movement. However, it takes a lot of effort to manage the safety of workers. (C) Cracks and junkers may occur on the hardened concrete surface, and the finished state of the surface may be unsightly.

In view of the above circumstances, it is an object of the present invention to provide a concrete dam that can be constructed quickly and safely, and that can achieve high quality, and a construction method thereof.

[0007]

A concrete dam according to claim 1 comprises a dam body made of concrete, and a dam surface layer portion formed by a number of precast plates on the upstream and downstream sides of the dam body. To be done.

According to a second aspect of the present invention, there is provided a method for constructing a concrete dam, comprising a first step of providing a plurality of precast plates on the upstream side and the downstream side of a dam construction area so as to form a concrete placing space therein. Concrete in the concrete placing space, the second step of placing so as to fill the precast plate, the upper end of the precast plate provided on the upstream side of the dam construction area, and the downstream side of the dam construction area A plurality of precast plates on the upper end of the precast plate provided in, respectively, so as to form the next concrete placing space above the already placed concrete, and the next concrete placing space A fourth step of placing concrete so as to bury the precast plate, and the third step and the fourth step. So as to launch a concrete, characterized in that construction the embankment by repeating the process.

The method for constructing a concrete dam according to claim 3 is the method for constructing a concrete dam according to claim 2, wherein the concrete dam is provided so as to form the already-exposed concrete and the next concrete placing space. An anchor is provided between the precast plate and the precast plate.

The construction method of the concrete dam according to claim 4 is the construction method of the concrete dam according to claim 2 or 3, wherein the precast plate on the upstream side of the dam construction area and the downstream side of the dam construction area. A feature is that a connecting material is provided between the precast plate and the precast plate.

[0011]

According to the concrete dam of the first aspect, since the dam surface layer portion is formed by a large number of precast plates, the surface finish can be improved. In addition, by filling the precast plate into a formwork, the precast plate performs a heat insulating function, and heat generated during hardening of the concrete cast to form the dam body, and cracking due to the heat effect due to subsequent contraction. Can be suppressed.

Further, by using the precast plate as a buried mold, it is possible to omit large-scale work such as installation, removal, movement and disassembly of the mold in the conventional construction of a concrete dam.

Further, when the concrete is poured up by using the precast board as a burying mold, a precast board for forming the next concrete placing space is provided on the precast board on which the concrete is placed. By this, it is possible to perform the connecting work of the precast plates as the burying formwork from the already placed concrete. Therefore, large-scale work at high places, such as the work of attaching the formwork to the upstream side and the downstream side of the dam body formed by the already cast concrete and the work of removing it for movement, as in the past, is omitted. You can

According to the concrete dam construction method of the second aspect, since the precast plate is used as a buried formwork, large-scale work such as installation, removal, movement and dismantling of the formwork in the construction of conventional concrete dams is performed. Can be omitted.

Further, since the precast plate is provided on the existing precast plate, the connecting work can be performed from the already cast concrete. Therefore, large-scale work at high places, such as the work of attaching the formwork to the upstream side and the downstream side of the dam body formed by the already cast concrete and the work of removing it for movement, as in the past, is omitted. You can

Further, since the dam surface layer portion is formed by a large number of precast plates, the surface finish can be improved. In addition, since the precast plate that serves as the buried mold has a heat insulating effect, it is possible to suppress the generation of heat during hardening of the concrete cast to form the dam body and subsequent cracking due to the heat effect due to contraction. I can.

According to the method for constructing a concrete dam according to claim 3, since the precast plate is supported by the anchor, it is possible to prevent the precast plate from being deformed outward by the pressure of the concrete at the time of placing the concrete. .

According to the method for constructing a concrete dam of claim 4, the precast plate can be prevented from being deformed outward by the pressure of the concrete when the concrete is poured by the connecting material.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a concrete dam 10 of the present invention during construction.
It is a figure which shows one Example of 0, and concrete dam 100
Is a dam surface layer portion 1 which is vertically formed so as to face the upstream side (left side in FIG. 1) and the downstream side (right side in FIG. 1) of the dam.
The dam surface layers 10 and 10 are composed of a plurality of precast plates 1 that are continuously arranged in the up-down direction and the left-right bank direction (direction perpendicular to the plane of FIG. 1). . In addition, the dam surface layer portion 10 on the downstream side (right side in FIG. 1)
Are provided on the upstream side with a slight inclination.

As shown in FIG. 6, each precast plate 1 is a member formed in advance into a rectangular plate shape by concrete or the like, and the inner surface of the precast plate 1 has a spliced joint. It is the processing surface 1a. The upper end surface 1b and the lower end surface 1c of the precast plate 1 are formed at right angles to the splicing surface 1a of the precast plate 1. The left end surface 1d and the right end surface 1e of the precast plate 1 are tapered so as to narrow toward the piecing surface 1a.

The precast plate 1 has an upper end surface 1b, a lower end surface 1c, a left end surface 1d, and a right end surface 1e, and a splicing surface 1
A plurality of grooves 2 cut out on the a side are formed respectively, and a connecting metal fitting 3 is provided in the groove 2, and the connecting metal fitting 3 is adjacent to an upper side, a lower side, a left side or a right side of the precast. It has a pin hole 3a penetrating toward the plate 1.

As shown in FIG. 7, the precast plates 1, 1 adjacent to each other in the vertical direction or the horizontal direction are connected to the upper end face 1b, the lower end face 1c or the left end face 1d, and the right end face 1e as shown in FIG. The pin holes 3a of 3 are aligned, the bolts (not shown) are passed through the pin holes 3a, 3a that are aligned, and the nuts (not shown) are tightened to connect them.

Further, as shown in FIG. 8, a gasket 4 is provided at the end on the surface 1f side of the precast plate 1 between the lower end surface 1c and the upper end surface 1b of the vertically adjacent precast plates 1, 1. A mortar 5 is filled between the lower end surface 1c and the upper end surface 1b of the vertically adjacent precast plates 1, 1 on the side of the gasket 4 which is the splicing treated surface 1a.

As shown in FIG. 9, a gasket 6 is provided at the end on the surface 1f side of the precast plate 1 between the left end face 1d and the right end face 1e of the left and right precast plates 1, 1. And precast plates 1 and 1 that are adjacent to each other
A sealing material 7 is provided between the left end surface 1d and the right end surface 1e on the splicing surface 1a side of the gasket 6.

As shown in FIG. 1, concrete 11 is cast between the dam surface layers 10 and 10 formed by the precast plate 1 in layers from the bottom to the top. The dam body 20 is formed.

A back anchor 12 embedded in concrete 11 is provided on the splicing surface 1a side of each precast plate 1 forming the dam surface layers 10 and 10, and the lower end of the back anchor 12 is provided. Is located on the upper surface of the layer of concrete 11 below the precast plate 1 provided with the back anchor 12.

That is, as shown in FIG. 6, a plurality of internal thread metal fittings 8 are embedded in the upper and lower rows on the connecting surface 1a of the precast plate 1, and the female thread metal fittings 8 are shown in FIG. As described above, the male screw 9 having the ring 9a at the end is screwed. Further, on the upper surface of the layer of concrete 11 below the precast plate 1, female screw metal fittings 13 are embedded so as to correspond to the respective male screws 9, and the female screw metal fittings 13 are embedded.
A male screw 14 having a ring 14a at its end is screwed onto the. The above-described back anchor 12 is provided between the ring 9a on the side of the precast plate 1 and the ring 14a on the side of the concrete 11.

The back anchor 12 is an upper rod member 12a.
And a lower rod member 12b, and a turnbuckle 12c that joins the upper rod member 12a and the lower rod member 12b so that the entire back anchor 12 can expand and contract, and a hook 12d is provided at the upper end of the upper rod member 12a. Has been. The hook 12d is a ring 9a on the precast plate 1 side.
The lower rod member 12b is also provided with a hook 12e at the lower end thereof. That hook 12
e is inserted and hooked on the ring 14a on the concrete 11 side. Also, the hooks 12d and 12e and the rings 9a and 1
4a is hooked in a state with almost no play.

Since the concrete dam 100 has the above-mentioned structure, as shown in FIG. 1, since the dam surface layer portion 10 is formed by a large number of precast plates 1, the surface finish can be improved. I can. Therefore, the quality of the concrete dam 100 can be improved.

The concrete dam 100 is shown in FIG.
The construction can be performed by repeating the construction process shown in. That is, first, in the precast plate suspending step C1, as shown in FIG. 2 or 4, the precast plate 1 that is already installed on the upstream side and the downstream side of the dam construction region Sd and forms the lower parts of the dam surface layer portions 10 and 10. At the top of the crane 31
Thus, the next precast plate 1 is hung so that the splicing surface 1a of the precast plate 1 faces inward. The crane 31 is a suspending device such as a cable crane installed above the dam construction area Sd or a crawler crane carried on the dam body 20 already installed by the concrete 1.

Next, in the positioning step C2 shown in FIG. 11, the suspended precast plate 1 is moved to the existing precast plate 1 by an operator who stands by under the existing dam body 20 as shown in FIG. 1 upper end surface 1b of the connecting fitting 3
Then, the position of the connecting fitting 3 on the lower end surface 1c of the suspended precast plate 1 is guided and positioned so as to match.

Next, the connecting metal fitting step C3 shown in FIG.
Then, the connecting metal fitting 3 of the upper end surface 1b of the existing precast plate 1 and the connecting metal fitting 3 of the lower end surface 1c of the suspended precast plate 1 are connected by bolts and nuts in the suspended state.

In the joint treatment step C4 shown in FIG. 11, in the process of connecting the existing precast plate 1 and the suspended precast plate 1 as described above, the upper surface 1b of the existing precast plate 1 is As shown in FIG. 8, a gasket 4 is provided between the lower end surface 1c of the suspended precast plate 1 and the end on the front surface 1f side.
The mortar 5 is provided closer to the splicing surface 1a. This makes it possible to prevent water from permeating through the joints between the vertically adjacent precast plates 1.

When the connection between the existing precast plate 1 and the suspended precast plate 1 and the joint treatment are completed, the process proceeds to the back anchor installation step C5 shown in FIG. In the back anchor installation step C5, as shown in FIGS.
As shown in, the back anchor 12 is attached between the suspended precast plate 1 and the lower part of the dam body 20 formed by the already cast concrete 11.

On the upper surface of the concrete 11 forming the lower part of the dam body 20, before the concrete 11 hardens, a plurality of female screw fittings 8 provided on the precast plate 1 are provided as shown in FIG. A plurality of corresponding internal thread fittings 13 are embedded.

In mounting the back anchor 12, first, the male screws 9 each having the ring 9a are screwed into the female screw fittings 8 provided in two rows above and below the joining surface 1a of the precast plate 1, and similarly. A male screw 14 having a ring 14a is screwed onto each female screw fitting 13 provided on the already-cast concrete 11. Next, the hook 12d of the upper rod member 12a of the back anchor 12 was inserted into and hooked on the ring 9a of the male screw 9 of the precast plate 1, and the hook 12e of the lower rod member 12b was provided on the already cast concrete 11. Insert and hook onto the ring 14a of the male screw 14. Then, the back anchor 12 is expanded and contracted by the turnbuckle 12c of the back anchor 12 to adjust the installation angle of the precast plate 1.

Therefore, the suspended precast plate 1
Can be accurately installed at a predetermined installation angle by the back anchor 12, and the existing concrete 1
Fixed to 1. Further, as shown in FIG. 7, the back anchors 12 are provided on the upper and lower sides of the precast plate 1, respectively, and a plurality of back anchors are provided in the left and right bank directions. Therefore, the precast plate 1 should be firmly fixed to the concrete 11 already placed. Can be done.

Further, as shown in FIG. 1, the dam construction area S
It is already installed on the upstream side and the downstream side of d, and the dam surface layers 10, 1
As shown in FIG. 7, a large number of precast plates 1 forming the lower part of 0 are continuously arranged in the left-right bank direction, and the precast plates 1 are suspended on each of the precast plates 1 in the same manner as described above. They are rarely connected and are fixed to the existing concrete 11 by the back anchor 12.

The precast plates 1 provided on the existing precast plates 1 are connected to each other so that the precast plates 1 adjacent to each other in the left and right bank direction are connected to each other. The connection is performed by fastening the connecting fittings 3 and 3 provided on the left and right end faces 1d and 1e of the adjacent precast plates 1 with bolts and nuts.

Further, in the process of connecting the adjacent precast plates 1, as shown in FIG. 9, the left and right end faces 1d and 1e are provided with gaskets 6 at the ends on the surface 1f side, and the gaskets 6 are joined together. A sealing material 7 is provided on the processing surface 1a side. As a result, the precast plates 1 adjacent to the left and right
Water can be prevented from penetrating from the joints between.

Therefore, as shown in FIG. 5, the dam surface layer portion 10, which has already been installed upstream and downstream of the dam construction area Sd,
Since the precast plate 1 can be further provided on the precast plate 1 forming the lower part of 10, the concrete pouring space S1 can be further formed in the meantime, that is, on the already cast concrete 11.

Further, the connection of the existing precast plate 1 and the suspended precast plate 1 and the connection of the suspended precast plates 1 are such that the connecting metal fitting 3 is provided on the side of the precast plate 1 where the splicing treatment surface 1c is formed. Since it is provided in the formed groove 2, it can be performed on the already cast concrete 11. Further, the suspended precast plate 1 can be fixed to the existing concrete 11 as described above from the already-cast concrete 11. Therefore, since the installation work of the precast plate 1 on the existing precast plate 1 can be performed from the already-cast concrete 11, the upstream side of the bank formed by the already-cast concrete as in the conventional art. Also, it is possible to omit large-scale work at a high place such as a work of mounting the formwork on the downstream side and a work of removing it for movement. Therefore, the safety of construction can be improved.

Then, the concrete placing step C in FIG.
At 6, the concrete 11 is placed in the concrete placing space S1 shown in FIG. At this time, the precast plate 1 is
Since it is fixed to the already-cast concrete 11 by the back anchor 12, it is possible to prevent the precast plate 1 from being deformed outward by the pressure of the concrete 11 when the concrete is poured, thus further improving the quality. Can be planned.

The surface of the precast plate 1 on the concrete pouring space S1 side is a connecting surface 1a subjected to a connecting process, and the back anchor 12 provided on the precast plate 1 is made of concrete 11. Since it is buried, the precast plate 1 and the concrete 11 can be strongly bonded.

As described above, the precast plate 1 serving as the buried mold has a heat insulating function, so that the heat generated when the concrete 11 cast to form the dam body 20 is hardened,
It is possible to suppress the occurrence of cracks due to the thermal action during the subsequent contraction. Therefore, high quality can be achieved.

Further, since the precast plate 1 is used as a buried formwork, large-scale work such as installation, removal, movement, and disassembly of the formwork in the construction of a conventional concrete dam can be omitted, so that the construction can be speeded up. Can be planned.

The above is one cycle of the construction process of the concrete dam 100 of the present invention. By repeating this cycle, the dam surface layer portion 10 is formed by the precast plate 1 and the dam body 20 is formed by the concrete 11. Can be done. Further, as described above, the high-quality concrete dam 100 can be constructed quickly and safely.

When the precast board 1 is installed on the foundation of the concrete dam 100, the precast board installation portions are formed on the upstream side and the downstream side of the foundation, and the connecting metal fittings of the precast board 1 are formed on the upper end of the installation portion. The same operation as described above can be performed by providing a connecting metal fitting similar to No. 3 and further embedding an internal thread metal fitting similar to the female thread metal fitting 13 embedded in the already cast concrete 11 on the foundation.

In the above embodiment, the back anchors 12 are provided in two rows above and below the precast plate 1. However, the back anchors 12 do not necessarily have to be in two rows, and one row may be provided depending on the size of the precast board 1. Needless to say, the number of rows may be three or more.

Further, in the above embodiment, the back anchor 1
2, the precast plate 1 is provided so as to prevent the deformation of the precast plate 1 at the time of placing concrete.
As shown in FIG. 13, in addition to the back anchor 12, by installing a connecting member 31 on the upper ends of the precast plate 1 provided on the upstream side and the precast plate 1 provided on the downstream side, Deformation may be prevented. As a result, the effect of preventing deformation can be enhanced, so that the quality can be further improved.
In this case, both ends of the connecting member 31 are, as shown in FIG.
It is formed so as to be connected to a connecting fitting 3 provided on the upper end of the precast plate 1 by bolts and nuts, and further, on the lower surface of both end portions of the connecting member 31 and the upper end portion of the splicing surface 1a of the precast plate 1. Between the brackets 32
By providing, the connecting force between the connecting member 31 and the precast plate 1 can be increased. Further, as shown in FIG. 13, the connecting member 31 is provided for each of the connecting fittings 3 provided at the upper end of the precast plate 1.

Further, in the above embodiment, the concrete casting space S1 is formed by the one-stage precast plate 1. However, as shown in FIG. Of course, the space S1 may be formed.

Further, in the above-mentioned embodiment, as shown in FIG. 10, the ring 9 is provided on the side of the precast plate 1 which is the splicing surface 1a.
The male screw 9 having a is provided, and the already cast concrete 11
The male screw 14 having the ring 14a is provided on the back anchor 12, and the back anchor 12 is provided between the two so as to be hooked by the hooks 12d and 12e at both ends thereof. The male screw 9 and 14 are the male screw having the welding plate. Both ends may be welded plates, and the back anchor 12 may be provided so as to be welded to the male screws 9 and 14.

Further, a rod-shaped or plate-shaped back anchor is embedded in the already cast concrete 11 so that its upper end is located near the installation position of the precast plate 1, and the precast plate 1 is spliced. By forming a wide welding plate on the processing surface 1a side, the precast plate 1
The back anchor may be welded after the installation angle is adjusted.

[0054]

According to the concrete dam of the first aspect, the surface finish can be improved, and the heat generated when the concrete cast to form the dam body is cured,
Since it is possible to suppress the occurrence of cracks due to the thermal action due to the subsequent contraction, it is possible to improve the quality.
Further, since it is possible to omit large-scale work such as installation, removal, movement, and disassembly of the formwork in the construction of the conventional concrete dam, the construction can be speeded up. Further, since it is possible to omit the conventional large-scale work at a high place, it is possible to improve construction safety.

According to the concrete dam construction method of the second aspect, the same effects as those of the concrete dam of the first aspect can be obtained.

According to the method for constructing a concrete dam according to claim 3, in addition to the above effects, it is possible to prevent the precast plate from being deformed outward by the pressure of the concrete when placing the concrete by the anchor.
It is possible to further improve the quality.

According to the method of constructing a concrete dam according to claim 4, in addition to the above effects, it is possible to prevent the precast plate from being deformed outward by the pressure of the concrete when the concrete is poured by the connecting material. It is possible to further improve the quality.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a concrete dam of the present invention during construction.

FIG. 2 is a diagram showing a construction process of the concrete dam shown in FIG. 1, and is a diagram showing a state in which a next precast plate is suspended from an existing precast plate on the upstream side.

FIG. 3 is a view showing a construction process of the concrete dam shown in FIG. 1, and is a view showing a state in which a next precast plate is installed on an existing precast plate on the upstream side.

FIG. 4 is a diagram showing a construction process of the concrete dam shown in FIG. 1, and is a diagram showing a state in which a next precast plate is suspended from an existing precast plate on the downstream side.

FIG. 5 is a diagram showing a construction process of the concrete dam shown in FIG. 1, and is a diagram showing a state in which the following precast plates are respectively installed on the existing precast plates on the upstream and downstream sides.

6 is a diagram showing the precast plate of FIG. 1. FIG.

FIG. 7 is a perspective view showing an installed state of the precast plate of FIG.

8 is a diagram showing joints between vertically adjacent precast plates in FIG. 7. FIG.

FIG. 9 is a diagram showing joints between the precast plates adjacent to each other on the left and right sides of FIG. 7.

10 is a diagram showing the back anchor of FIG. 7. FIG.

11 is a flowchart showing a construction process of the concrete dam shown in FIG.

FIG. 12 is a front view showing another embodiment of the concrete dam of the present invention.

FIG. 13 is a plan view showing the concrete dam of FIG.

FIG. 14 is a diagram showing a conventional concrete dam.

FIG. 15 is a view showing an automatic formwork used for construction of a conventional concrete dam.

[Explanation of symbols]

 1 ... Precast board 11 ... Concrete 12 ... Back anchor (anchor) 20 ... Dam body 31 ... Connection material Sd ... Dam construction area S1 ... Concrete placing space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Natsuo Hara 2-1026 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Hideaki Asai 2-1026 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd.

Claims (4)

[Claims] 1. A dam body (20) made of concrete (11), and a dam surface layer (10) formed by a number of precast plates (1) on the upstream side and the downstream side of the dam body (20), respectively. A concrete dam composed by. 2. A first step of providing a plurality of precast plates (1) on the upstream side and the downstream side of a dam construction area (Sd) so as to form a concrete placing space (S1) therein, and the concrete. In the pouring space (S1), concrete (1
The second step of placing 1) so that the precast plate (1) is buried and buried, the upper end of the precast plate (1) provided on the upstream side of the dam construction region (Sd), and the dam Construction area (Sd)
On the upper end of the precast plate (1) provided on the downstream side of
A third step of providing a plurality of precast plates (1) so as to form a next concrete placing space (S1) above the already placed concrete (11), and the following concrete placing space ( S1) has a fourth step of placing the concrete (11) so that the precast plate (1) is buried and buried, and the concrete (11) is obtained by repeating the third step and the fourth step. The concrete dam construction method is characterized in that the dam body is constructed so that 3. The method for constructing a concrete dam according to claim 2, wherein the precast plate (11) is provided so as to form the already placed concrete (11) and the next concrete placing space (S1). A method for constructing a concrete dam, characterized in that an anchor (12) is provided between the anchor and (1). 4. The method for constructing a concrete dam according to claim 2, wherein the precast plate (1) upstream of the dam construction area (Sd) and the precast downstream of the dam construction area (Sd). A method for constructing a concrete dam, characterized in that a connecting material (31) is provided between the board (1).