JPH0469694B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for constructing a concrete dome that does not require a support frame, a support steel frame, etc. or can be made simple, and is suitable for use in nuclear reactor buildings and It can also be used to construct dome roofs for other general buildings.

[Conventional technology and problems]

As shown in Fig. 12, a common dome construction method involves assembling a three-dimensional truss-shaped dome steel frame 32 and an inner cast-off frame on a support frame 31.
This method uses an upper formwork to pour concrete on top of that.

However, in that case, a support frame 31 to cope with the weight of the concrete and a dome steel frame 32 as a supporting steel frame are required, which requires a large amount of steel, cost, and construction time, and there are restrictions on the concrete placement classification. . Regarding the dome steel frame 32, in the future,
Maintenance such as steel painting is difficult.

In contrast, a method has been considered in which the dome is constructed by repeatedly replacing the formwork and pouring concrete from the bottom of the dome to the top.

However, even if the lower part is fine, supporting the formwork becomes a problem as you move toward the top, and usually the lower (inner) formwork inevitably requires a support frame or the like.

In addition, in a nuclear reactor building, a construction method when constructing a dome outside the steel shell containment vessel (hereinafter referred to as SVC) is to use a lower formwork unit that slides on an existing SVC using a trolley. There is a method in which the dome is constructed upward by connecting the upper formwork unit fixed to anchors in the existing concrete part and moving it sequentially, pouring concrete and building the dome upward.

However, the above method cannot be used for constructing reactor buildings such as FBRs (fast breeder reactors) that do not have SVC underneath, or for constructing concrete dome roofs for general buildings.

This invention aims to solve the problems in the prior art as described above.

[Means for solving problems]

In the dome construction method of the present invention, a lower formwork unit 1 as a waste formwork is first constructed in advance and assembled to the top, and then an upper formwork unit 4 that can be moved upwards is used to construct the lower part of the dome A. Concrete will be poured from the top to the top.

The upper formwork unit 4 is supported by connecting the rear part of a support body 5 consisting of a steel beam and necessary fishing members 10 and the like to anchors 22 buried in the existing concrete 23. Then, the tip of the upper formwork unit 4 is connected to the previously constructed lower formwork unit 1 by means of a hanging material 8, so that the lower formwork unit 1 can withstand the concrete pouring pressure in advance. Concrete 23 in the next step is poured with prestress introduced. Dome A is constructed by repeating this operation.

Note that the lower formwork unit 1 constructed in advance can be used as a temporary scaffold for reinforcement work until the concrete 23 is poured.

Further, since the dome A becomes narrower as it goes upward, the weir plates 6, etc. of the upper formwork unit 4 are sequentially cut off every time it is rearranged upward.

〔Example〕

Next, the illustrated embodiment will be described.

FIG. 1 shows an outline of the present invention, in which a lower formwork unit 1 consisting of a section steel 3 and a deck plate 2 is used as a waste formwork, and is successively added above the existing lower formwork unit 1. Assemble it to the top in advance. The lower formwork units 1 can be connected to each other using bolts or the like.

The upper formwork unit 4 has a weir plate 6 attached to the lower front surface of a support body 5 made of a steel beam or the like, and is connected and fixed to an existing anchor 22 by a connecting member 7. Further, a support 9 is erected on the support main body 5 of the upper formwork unit 4, and the upper end of the support 9 and the front and rear ends of the support main body 5 are connected in a truss shape by a fishing member 10 such as PC steel. Reinforced.

Angle-adjustable scaffolds 11a, 11b are attached to the upper formwork unit 4, and reinforcing scaffolds 12a, 12b may be further connected to the lower side.

In the figure, 21 is an anchor projecting from the upper surface of the lower formwork unit 1, and 24 is an arranged reinforcing bar.

Next, the construction procedure will be explained according to FIGS. 2 to 6.

As shown in Figure 2, the lower formwork units 1 are erected one by one using a crane, and the existing lower formwork units 1 are
Connect with bolts, etc. In this way, the lower formwork unit 1 is first assembled to the top.
If necessary, a support frame or the like may be provided, but it may be simple enough to support the weight of the temporary scaffold.

Using the upper formwork unit 4, concrete is poured step by step, and as shown in FIG. 3, concrete 23 for the final step is poured.

As shown in Figure 4, the reinforcing bar 2 of the next step part
4, and lift the upper formwork unit 4 with a crane or the like and reposition it. At this time, the extra width of the weir plate 6 is cut off.

In this state, the lower formwork unit 1 is suspended by tensioning the hanging material 8 so that it can withstand the pouring pressure of the concrete 23 in advance.

As shown in FIG. 5, concrete 23 is placed and reinforcement is placed in the next step.

As shown in Fig. 6, the upper formwork unit 4 is
Replacement and final step of concrete 23
Carry out pouring. Return to step 1 and repeat the above steps. FIG. 7 shows the appearance of the dome A during construction, and construction is carried out while the upper formwork units 4 are successively moved upward. Note that, as described above, the upper formwork becomes narrower as it goes upward, so the upper formwork will be sequentially cut.

8 and 9 show an example of the structure of the lower formwork unit 1, in which a deck plate 2 is placed on the upper flange of the section steel 3. As shown in FIG. In addition, Fig. 9a shows the 9th section when the section steel 3 is an H section steel 3a.
Figure b shows a case where the section steel 3 is a channel steel 3b. Also,
In the figure, reference numeral 25 is an adjustment iron plate that cools the gap between adjacent units.

10 and 11 show another example of the lower formwork unit 1 in which a deck plate is placed on the lower flange of a section steel 3. In addition, a thin precast concrete plate or the like may be used as the lower formwork unit 1.

〔Effect of the invention〕

In the dome construction method of this invention, the lower formwork unit as a waste formwork is assembled up to the top by advance construction, and then the removable upper formwork unit is supported by the existing concrete part, and the hanging members are tensioned. Since the lower formwork can withstand the concrete pouring pressure and the dome can be built upwards, there is no need for supporting frames, supporting steel frames, etc. or temporary scaffolding to cope with the weight of the concrete. A simple one that supports this will be sufficient. Therefore, the construction work of the dome is simplified, and the construction cost and construction period can be shortened. In addition, concrete placement can be planned freely and waste is reduced.

Additionally, since the lower formwork unit is constructed in advance up to the top, all-weather protection can be ensured during construction of the lower building, resulting in a high level of safety.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing the usage state of the device used in this invention, Figs. 2 to 6 are longitudinal sectional views showing the construction procedure, Fig. 7 is a perspective view showing the state of dome construction, and Fig. 8 The figure is a side view showing an example of the lower formwork unit, FIGS. 9a and 9b are sectional views of different aspects thereof, and FIG. 10 is a side view showing another example of the lower formwork unit.
Figures 11a and 11b are cross-sectional views of different aspects of the
Figure 2 is a longitudinal sectional view showing the conventional construction method. A...Dome, 1...Lower formwork unit, 2...
Deck plate, 3... Shaped steel, 4... Upper formwork unit, 5... Support body, 6... Shelter plate, 7... Anchor connecting material, 8... Hanging material, 9... Support column, 10...
...Fishing member, 11a, 11b...Scaffolding, 12
a, 12b...Auxiliary scaffolding, 21, 22...Anchor, 23...Concrete, 24...Reinforcement, 25
... Adjustment iron plate, 31 ... Support frame, 32 ... Dome steel frame.

Claims (1)

[Claims] 1 After constructing the lower formwork unit as a waste formwork in advance and assembling it to the top, anchors were buried in the existing concrete part at the rear of the upper frame unit with a weir plate attached to the front lower surface of the support body made of steel beams. The upper formwork unit is supported at the tip of the existing concrete part, and the tip of the upper formwork unit and the lower formwork unit are connected via a hanging material, and the hanging material is connected to the lower formwork unit. A dome construction method characterized by sequentially pouring concrete in steps while the lower formwork unit is made to withstand concrete pouring pressure by tensioning the lower formwork unit.