JP5777050B2 - Side wall construction method for concrete structures - Google Patents

Description

  The present invention relates to a side wall construction method for a concrete structure such as a concrete ground tank for storing liquefied gas such as LNG.

Conventionally, a ground tank for storing liquefied gas such as LNG has been constructed, and in the case of a large tank, the height of a reinforced concrete liquid barrier (side wall) is close to 50 m.
When constructing such a side wall, concrete is successively handed over from the lower side of the side wall to the upper side. Usually, since the launch height of one time (lot) is about 5 m, if the height of the side wall is about 50 m, it will be handed over about 10 times, and a long construction period is required for placing concrete. .

Also, in underground tanks, the side walls of the underground tank are constructed by sequentially casting the concrete from the lower side to the upper side. Therefore, in the case of a large-sized tank, a long work period is required for placing the concrete.
Then, the construction method which shortens the construction period concerning the placement of the concrete of the side wall of an underground tank is known. For example, Patent Documents 1 and 2 disclose a method for constructing a side wall of an underground tank that can set the launch height of one lot of the side wall high.
In these underground tank side wall construction methods, when performing the reinforcement work and the formwork for a lot of concrete placement area, the entire concrete placement area is divided into a lower placement area and an upper placement area. Separately, a part of the reinforcement will be post-constructed at the boundary between the lower placement area and the upper placement area, and a work space for concrete placement work will be secured there. Yes.

JP 2007-63894 A JP 2007-63895 A

  However, in the underground tank side wall construction methods disclosed in Patent Documents 1 and 2, workers are working in the work space in the mold, but in the case of the side wall of the ground tank, the wall thickness is Since it is smaller than the underground tank and is about 70 cm, it is not possible to secure a working space in which a worker can enter the formwork, and the side wall construction method for these underground tanks cannot be applied.

  The present invention has been made in view of the above-described circumstances, and in placing concrete on a side wall in the construction of a concrete structure such as a ground tank, a concrete structure capable of setting the placement height of one lot large. An object of the present invention is to provide a side wall construction method.

In order to achieve the above object, the method for constructing a side wall of a concrete structure according to the present invention performs the placement of concrete on the side wall for each lot divided into a plurality of heights in the construction of the side wall of the concrete structure. In the method for constructing a side wall of a concrete structure, a mold installation step for installing a formwork in which an opening is formed in an intermediate part in the height direction in a concrete placing region of one lot, and the opening in the formwork A concrete is placed to the lower side, and a vibrator is inserted through the opening and a lower concrete placing process for compacting the placed concrete, and after the lower concrete placing process, the opening is covered with a cover material. Upper concrete that closes and places concrete up to the upper end of the formwork and inserts a vibrator from the upper side of the formwork to compact the placed concrete. Comprising a preparative hitting set step, the mold includes a Yokotan Futoshizai contact with the mold frame vertically extending horizontally arranged at a predetermined interval, extend in the vertical direction It is supported by the vertical end thick material arranged via the horizontal end thick material between the formwork at a predetermined interval in the horizontal direction, and the horizontal end thick material and the vertical end thick material are Installed at a position that does not interfere with the opening, between the opening upper horizontal end thick material installed on the upper side of the opening and the opening lower horizontal end thick material installed on the lower side of the opening, A movable horizontal end thick material that can move in the vertical direction between the upper horizontal end thick member and the lower lower end thick member is temporarily placed at a position that does not substantially interfere with the opening. In the state in which the lid material is fitted, the movable lateral end thick material is moved to a position where it comes into contact with the lid material, and the vertical end thick material is engaged with the lid. Characterized by fixing the.

  In the present invention, since the opening is formed in the intermediate portion in the height direction of the mold in the one-place concrete placement region, the compaction of the concrete placed below the opening can be compacted from this opening. The concrete can be compacted from above the formwork, so the concrete can be compacted even when the height of the concrete placement area of one lot is higher than before. Can be done. Thereby, since the placement height of 1 lot of concrete can be set higher than before, a side wall can be constructed efficiently.

Also, it is possible to easily fix the lid to the open mouth.

Moreover, in the side wall construction method for a concrete structure according to the present invention, it is preferable that the mold is formed of a transparent material below the opening and configured so that the inside can be confirmed from the outside. .
By doing in this way, the placing condition of the concrete below an opening part can be confirmed visually.
Thereby, even when the height of the concrete placement area of one lot is higher than before, the state of the lower concrete can be visually confirmed, so that the side wall can be efficiently constructed.

  According to the present invention, since the opening is formed in the intermediate portion in the height direction of the formwork in the concrete placement area of one lot, the compaction of the concrete placed below the opening can be compacted. Since the concrete above the concrete can be compacted from above the formwork, the concrete compaction can be achieved even when the height of the concrete placement area of one lot is higher than before. Can be performed reliably. Thereby, since the placement height of 1 lot of concrete can be set higher than before, a side wall can be constructed efficiently.

It is a figure which shows an example of the side wall by embodiment of this invention. (A) is a front view which shows an example of the formwork by embodiment of this invention, (b) is the sectional view on the AA line of (a). It is a figure explaining a formwork with an opening part. It is a figure explaining the internal peripheral surface of the opening part of a formwork with an opening part, and the outer peripheral surface of a cover material. (A) is a front view which shows an example of the formwork in which the cover material was installed in the opening part, (b) is the BB sectional drawing of (a). (A) is a front view explaining the equipment of a concrete placement process, (b) is a top view explaining the equipment of a concrete placement process. It is a figure explaining a lower concrete placement process. It is a figure explaining an upper concrete placing process. It is a figure which shows one lot of the intermediate part of a side wall.

Hereinafter, a side wall construction method for a ground tank (concrete structure) according to an embodiment of the present invention will be described with reference to FIGS.
The method for constructing a side wall of a ground tank according to the present embodiment is a method of constructing a side wall 1 of a reinforced concrete ground tank as shown in FIG. 1, and the concrete placement of the side wall 1 is divided into a plurality of times in the height direction. Is going. Here, the description will be made assuming that one time of placing concrete is one lot.
In this embodiment, the cylindrical side wall 1 having a diameter of about 80 m and a height of about 45 to 50 m is constructed. For this reason, the concrete placement of the side wall 1 is performed in 6 lots (# 1 to # 6), and the concrete placement of the intermediate portion 4 excluding the bottom portion 2 and the top portion 3 of the side wall 1 is performed in 4 lots (# 2 to # 2). # 5). The concrete placement height per lot of the intermediate portion 4 is set to about 9 to 10 m.
And in the side wall construction method of the ground tank according to the present embodiment, the reinforcement work and the form work are performed for each lot, and the concrete is placed.

(Formwork)
First, the formwork used for construction of the middle part 4 of the side wall 1 of this embodiment is demonstrated.
As shown in FIG. 2, the mold 11 includes a lower mold 12 installed on the lower side of one lot, an upper mold 13 installed on the upper side, a lower mold 12 and an upper mold 13. The intermediate part formwork 14 is provided between the two. The lower mold frame 12, the upper mold frame 13, and the intermediate mold frame 14 are installed on the inner side and the outer side of the cylindrical side wall 1 with an interval corresponding to the thickness of the side wall 1, respectively. The lower mold 12, the upper mold 13, and the intermediate mold 14 are each formed in a cylindrical shape.

For example, the lower mold 12 is made of a transparent plate made of synthetic resin or the like and has a height of about 5 m, and is configured so that the concrete placed inside can be visually confirmed from the outside.
The upper mold 13 is a known mold made of wood or steel and has a height of about 3.5 m.

The intermediate part mold 14 is a wooden form with a height of about 1.5 m, a plurality of openings 15a are formed at predetermined intervals in the circumferential direction, and a shape corresponding to the openings 15a. And a lid member 16 (see FIG. 3) capable of closing the opening 15a.
In the present embodiment, the mold 17 with an opening in which the opening 15a is formed and the mold 18 without an opening without the opening 15a are alternately arranged in the circumferential direction to form the intermediate mold 14. Yes.
The opening 15a is formed to insert a vibrator 37 (see FIG. 7) for compacting the concrete cast in the lower mold 12.

As shown in FIG. 3, the mold 17 with the opening includes a frame member 15 in which an opening 15 a is formed and a lid member 16. The frame member 15 is formed with a width (dimension in the circumferential direction) of about 0.6 m, and the opening 15a is approximately at the center of the frame member 15 with a height of about 1.1 m and a width of about 0.3 m. Is formed. The lid member 16 is formed with a height of about 1.1 m and a width of about 0.3 m so as to be fitted into the opening 15a. When the cover member 16 is fitted into the opening 15a, the inner surfaces of the frame member 15 and the cover member 16 (surfaces on which concrete is placed) are configured to be flush with each other. .
In addition, as shown in FIG. 4, in the present embodiment, the tapered surface 15b narrows inward from the outside (side on which concrete is not placed) to the inner periphery of the opening 15a and the outer periphery of the lid member 16, 16b is formed.
Then, since the tapered surfaces 15b and 16b are formed on the inner peripheral portion of the opening 15a and the outer peripheral portion of the lid member 16, when the lid member 16 is installed in the opening 15a of the frame member 15 from the outside, the lid member 16 Can be installed at a predetermined position with respect to the frame member 15, and the inner surfaces of the frame member 15 and the lid member 16 can be easily flushed.

  Returning to FIG. 2, the lower mold frame 12, the upper mold frame 13, and the intermediate mold frame 14 are supported at predetermined positions by a lateral end thick member 21 and a vertical end thick member 22 that are installed outward. At the same time, the distance between the molds 11 facing each other by the separator 23 is maintained at a predetermined size.

  The horizontal end thick material 21 is installed so as not to interfere with the opening 15a of the intermediate mold 14 and is installed so as to support the lower mold 12 and the upper mold 13 in the vertical direction at a pitch of about 30 cm to 40 cm. ing. And in the intermediate | middle part formwork 14, it supports in the height of the upper part of the opening part 15a, and the lower part.

  The vertical end thick materials 22 are installed at a pitch of about 40 cm to 60 cm in the circumferential direction so as not to interfere with the openings 15 a of the intermediate mold 14 along the circumferential direction of the mold 11. The mold 11 is supported via the.

  The separators 23 are installed so as not to interfere with the openings 15a of the intermediate mold 14 and are installed at a pitch of about 60 cm in the circumferential direction of the mold 11 and about 60 cm in the vertical direction where there is no openings 15a. It is installed at a pitch of ˜70 cm, and is installed at a pitch of about 130 cm in a portion where the openings 15a are present.

In addition, between the lateral end thick material 21a installed on the upper side of the opening 15a of the intermediate part formwork 14 and the lateral end thick material 21b installed on the lower side, these lateral end thick materials 21a and 22b. A movable lateral end thick material 24 is provided which is configured to be movable in the vertical direction between them and capable of pressing the lid member 16 fitted in the opening 15a. The moving horizontal end thick material 24 is formed to have a thickness smaller than that of the horizontal end thick material 21.
Then, the moving horizontal end thick member 24 is installed so as to be positioned in the middle of the height direction of the cover member 16 as shown in FIG. 5 when pressing the cover member 16 fitted to the opening 15a. It is fixed by inserting a filling material 25 such as wedge between the thick material 22. Thereby, the cover material 16 is fixed to the opening part 15a.

(Ground tank side wall construction method)
Then, the side wall construction method of a ground tank is demonstrated. Here, the bottom part 2 and the top part 3 of the side wall 1 shall be constructed | assembled by the conventional method, and the construction method of the intermediate part 4 is demonstrated.
(Formwork installation process)
First, the placement of the lot (# 2) of the intermediate part 4 which is directly above the bottom part 2 shown in FIG.
As shown in FIG. 2, the mold 11 is installed by installing a lower mold 12, an intermediate mold 14, and an upper mold 13 from the lower side toward the upper side. Then, the separator 23 is installed, and the lower mold 12, the intermediate mold 14, and the upper mold 13 are supported by the vertical end thick material 22 and the horizontal end thick material 21.
At this time, the lid member 16 of the intermediate mold 14 is removed from the opening 15a, and the opening 15a is opened.
Moreover, it moves so that it may not interfere substantially with the opening part 15a between the horizontal end thick material 21a installed in the upper part of the opening part 15a of the intermediate part formwork 14, and the horizontal end thick material 21b installed in the lower part. The horizontal end thick material 24 is temporarily placed. In the present embodiment, two moving lateral end thick members 24 are temporarily placed, one is temporarily placed on the lateral end thick member 21b installed below the opening 15a, and the other is The temporary end is placed under the horizontal end thick material 21a installed above the opening 15a.
In the above, the moving lateral end thick material 24 is temporarily placed so as not to substantially interfere with the opening 15a because the moving lateral end thick material 24 is temporarily placed at the position of the vibrator 37 from the opening 15a to the inside of the mold 11. Any position that does not hinder the insertion may be used, and the movable lateral end thick member 24 is configured to be retractable from the opening 15a so as not to interfere with the opening 15a when the lid 16 is fitted to the opening 15a. This is because it may interfere somewhat with the opening 15a.
The moving horizontal end thick material 24 may be temporarily placed at a position where it does not interfere with the opening 15a at all.

(Concrete placing process)
Next, concrete is placed in the mold 11.
The concrete placement process in the mold 11 includes a lower concrete placement process in which concrete is placed in the lower mold 12, and an upper concrete placement in which concrete is placed in the intermediate mold 14 and the upper mold 13. It consists of two processes.
Also, as shown in FIGS. 6A and 6B, the concrete is placed in the mold 11 for placing concrete extending from above the upper mold 13 to the inside of the mold 11. Concrete is supplied from the tip (lower end) 31a of the hose 31 to the inside of the mold 11.
The concrete placing hose 31 has a base end portion (upper end portion) 31b connected to a concrete pumping horizontal pulling pipe 32 extending along the upper end portion 13a of the upper mold 13 above the upper mold 13. Then, one end portion 32a (see FIG. 6B) of the horizontal pulling pipe 32 is connected to a vertical pulling pipe 34 connected to the ground concrete pump car 33 (see FIG. 6A). Yes.

The horizontal piping 32 is formed to a length of about 40 m to 60 m, and a branch pipe 35 to which the concrete placing hose 31 can be connected is provided every about 2 to 4 m. Each branch pipe 35 is provided with a valve 36.
And in this embodiment, since the side wall 1 is formed in a cylindrical shape having a diameter of about 80 m and the circumference thereof is about 250 m, the concrete placement region is divided into 4 to 6 placement sections in the circumferential direction ( In this embodiment, it is divided into four as shown in FIG. 6B, and a horizontal pulling pipe 32 is installed for each placement section. At this time, the horizontal pulling pipes 32 are arranged in the circumferential direction so as to draw a circle along the upper end portion 13 a of the upper mold 13.
Further, in the horizontal pulling pipe 32, a vertical pulling pipe 34 is connected to one end portion 32a, and a concrete placing hose 31 is connected to each branch pipe 35.
These horizontal pulling pipe 32 and vertical pulling pipe 34 are supported by, for example, a scaffold.
The concrete placing hose 31, the horizontal pulling pipe 32, and the vertical pulling pipe 34 may have other forms.

(Lower concrete placing process)
First, the concrete placing process in the lower mold 12 will be described.
The concrete placing hose 31 is extended so that the tip 31 a reaches the inside of the lower mold 12, and the lower mold is passed from the concrete pump car 33 through the longitudinal pulling pipe 34, the lateral pulling pipe 32 and the concrete placing hose 31. Concrete is placed inside the frame 12.

  At this time, first, the valve 36 of the branch pipe 35 provided on the other end 32b side of the horizontal pull pipe 32 among the branch pipes 35 provided in the horizontal pipe 32 is opened, and the valves of the other branch pipes 35 are opened. 36 is in a closed state. Then, concrete is poured into the lower mold 12 from the concrete placing hose 31 connected to the branch pipe 35 having the valve 36 opened.

Subsequently, when the height of the placed concrete reaches about 50 cm, the opened valve 36 is closed, and one end portion 32a side of the horizontal pulling pipe 32 of the branch pipe 35 provided with the valve 36 is closed. The valve 36 of the adjacent branch pipe 35 is opened, and concrete is poured into the lower mold 12 from the concrete placing hose 31 connected to the branch pipe 35 having the valve 36 opened.
Then, when the height of the concrete cast from the concrete placing hose 31 reaches about 50 cm, the opened valve 36 is closed, and the horizontal piping 32 of the branch pipe 35 provided with the valve 36 is closed. The valve 36 of the adjacent branch pipe 35 on the one end 32a side is opened, and concrete is similarly placed.

In this way, the valves 36 of the branch pipes 35 are opened in order, and concrete is placed inside the lower mold 12 in order from the concrete placing hose 31 connected to each branch pipe 35.
At this time, since the lower mold 12 is formed of a transparent plate material, the concrete placement state can be visually confirmed from the outside of the lower mold 12.
Further, every time concrete is placed at a predetermined height (about 50 cm in the present embodiment), the tip 31a side of the concrete placement hose 31 is pulled upward, and the concrete placement according to the concrete placement height. The front end 31a side of the installation hose 31 is cut.

Then, by repeating the above concrete placement every about 50 cm, the concrete is filled up to the vicinity of the upper end of the lower mold 12 as shown in FIG. 5, and each opening of the intermediate mold 14 is shown in FIG. The vibrator 37 is inserted into the concrete of the lower mold 12 from 15a, and the concrete is compacted.
When the concrete compaction operation is completed, the vibrator 37 is taken out from the opening 15a.
This completes the lower concrete placing process.

(Upper concrete placing process)
Next, concrete is placed inside the intermediate mold 14 and the upper mold 13.
First, as shown in FIG. 5, the lid member 16 is fitted into the opening 15 a of the intermediate formwork 14, and the movable horizontal end thick member 24 is moved between the lid member 16 and the vertical end thick member 22. Then, the filling material 25 is inserted between the moving horizontal end thick material 24 and the vertical end thick material 22, and the lid material 16 is fixed. As a result, the opening 15a is closed.

Subsequently, concrete is placed inside the intermediate mold 14 and the upper mold 13.
In the upper concrete placing process, similarly to the lower concrete placing process, the valve 36 of the branch pipe 35 of the horizontal pulling pipe 32 is sequentially opened.
Then, as shown in FIG. 8, concrete is placed inside the intermediate mold 14 and the upper mold 13, and a vibrator 37 is inserted into the concrete placed from above the upper mold 13. Compact the concrete.

(Curing process / demolding process)
Subsequently, the concrete in the mold 11 is cured for a predetermined period. After the curing is completed, the mold 11 is removed, and one lot (# 2) of the intermediate portion 4 of the side wall 1 as shown in FIG. 9 is completed.

Subsequently, the lot (# 3) immediately above the lot (# 2) is constructed in the same manner as the lot (# 2), and then the upper lots (# 4, # 5) are constructed in order. In this way, the lot 5 immediately below the top portion 3 is completed, and the intermediate portion 4 of the side wall 1 is completed.
And the side wall 1 is completed by constructing the top part 3 of the side wall 1.

Next, the effect of the above-described ground tank side wall construction method will be described with reference to the drawings.
According to the method for constructing a side wall of the ground tank according to the present embodiment, the lower mold 12 is installed by installing the intermediate mold 14 in which the opening 15a that can be closed is formed between the lower mold 12 and the upper mold 13. Since the concrete to be placed in the frame 12 can be compacted from this opening 15a, the placement height of one lot of concrete can be set higher than before, and the side wall 1 is constructed efficiently. There is an effect that can be.
For example, in the conventional side wall side wall construction method, when constructing the same side wall 1, it is necessary to suppress the concrete placement of the intermediate portion 4 to a height of about 4.5 to 5.5 m per lot, Although the process is divided into 8 lots, in this embodiment, the height per lot can be set to nearly twice the conventional one, and the process is divided into 4 lots, so that the side wall 1 can be constructed efficiently.

As mentioned above, although embodiment of the side wall construction method of the ground tank by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, in the above-described embodiment, the lower mold 12 is entirely formed of a transparent material, but a part of the lower mold 12 may be formed of a transparent material, and only one of the inner and outer sides is formed. A transparent material may be used. Further, the lower mold 12 may not be formed of a transparent material.
In the embodiment described above, the dimensions of the mold 11 are set, but dimensions other than those described above may be used.

  In the above-described embodiment, concrete is placed inside the lower mold 12 in the lower concrete placing process, and concrete is placed inside the intermediate mold 14 and the upper mold 13 in the upper concrete placing process. In the lower concrete placing process, concrete is placed up to the height of the lower end of the opening 15a of the intermediate mold 14 in the lower concrete placing process. Concrete may be placed inside the mold from the lower end of the opening 15a up to the height range of the upper mold 13.

In the above-described embodiment, the intermediate mold 14 is configured such that the molds 17 with openings and the molds 18 without openings are alternately arranged. A configuration in which a plurality of molds 17 with openings is arranged by increasing the width dimension of the material 15 may be adopted. Moreover, the some opening part 15a may be formed in the mold 17 with an opening part at predetermined intervals in the circumferential direction.
In the above-described embodiment, the lid member 16 fitted to the opening 15a is fixed by the two moving lateral end thick members 24 in the upper concrete placing process, but the lid 16 is attached to the opening 15a. In the case where the intermediate formwork 14 in the fitted state can withstand the lateral pressure at the time of placing the concrete, the lid member 16 may be fixed by one moving lateral end thick material 24. In this case, the position where the moving horizontal end thick material 24 is temporarily placed in the lower concrete step may be either on the upper side or the lower side of the opening 15a. Moreover, you may fix the lid | cover material 16 fitted to the opening part 15a by the 3 or more moving horizontal end thick materials 24. FIG.
In the embodiment described above, the mold 11 is divided into the lower mold 12, the upper mold 13, and the intermediate mold 14. However, for example, the upper mold 13 and the intermediate mold 14 are integrated. It is not necessary to divide it.
In the above-described embodiment, the side walls of the ground tank are constructed. However, when constructing the side walls of the concrete structure other than the ground tank, for example, in the underground tank, the mold is formed only on one side inside the continuous underground wall. When constructing a side wall by installing a frame, the side wall construction method according to the present embodiment may be applied.

DESCRIPTION OF SYMBOLS 1 Side wall 11 Formwork 15a Opening part 16 Cover material 21 Horizontal end thick material 22 Vertical end thick material 24 Moving horizontal end thick material

Claims (2)

In the construction of the side wall of the concrete structure, in the side wall construction method of the concrete structure in which the placement of the concrete of the side wall is performed for each lot divided into a plurality in the height direction,
A mold installation process in which a mold having an opening formed in the middle in the height direction is installed in one lot of concrete placement area;
A lower concrete placing step of placing concrete into the mold to the lower side of the opening and inserting the vibrator from the opening to compact the placed concrete;
After the lower concrete placing step, the opening is closed with a lid material, concrete is placed up to the upper end of the formwork, and a vibrator is inserted from the upper side of the formwork to compact the placed concrete. An upper concrete placing process ,
The mold frame extends in the horizontal direction and is arranged at a predetermined interval in the vertical direction and is arranged at a predetermined interval in the vertical direction, and the horizontal end thick material that contacts the mold frame and extends in the vertical direction at a predetermined interval in the horizontal direction. It is supported by the vertical end thick material arranged via the horizontal end thick material between the formwork,
The horizontal end thick material and the vertical end thick material are installed at positions that do not interfere with the opening,
Between the opening upper horizontal end thick material installed on the upper side of the opening and the opening lower horizontal end thick material installed on the lower side of the opening, the opening is located at a position that does not substantially interfere with the opening. A moving horizontal end thick material that can move in the vertical direction between the upper horizontal end thick material and the opening lower horizontal end thick material is temporarily placed,
In a state in which the lid member is fitted in the opening, the movable lateral end thick material is moved to a position where it abuts on the lid member and is locked to the vertical end thick member to fix the lid member. A method for constructing a side wall of a concrete structure characterized by the above. 2. The method for constructing a side wall of a concrete structure according to claim 1 , wherein the mold is formed of a transparent material below the opening and is configured so that the inside can be confirmed from the outside. .

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