JPH0197706A - Construction method for forming concrete pillar - Google Patents

Abstract

PURPOSE: To greatly reduce working labors and costs by forming a column having a split part where it is bifurcated, through the placement of concrete while only scaffolds outside legs are pushed up at portions above the split part. CONSTITUTION: Concrete is placed as scaffolds 10 are pushed upward step by step along the legs 6, 7 of a concrete column, and when the inner scaffolds 10A, 10B of the legs 6, 7 are combined at a split part 8, a connecting scaffold 36 is assembled above their confluent part. Scaffolds 10B, 11B outside the legs are pushed upward and concrete is placed in the split part surrounded by the connecting scaffold 36 and the scaffolds 10B, 11B outside the legs. Further, as the scaffolds 10B, 11B outside the legs are pushed upward step by step along a vertical part 9 above the split part 8, concrete is placed in the vertical part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a construction method for forming a concrete column having a bifurcated branch part, which is used, for example, as a support for a bridge.

[Prior Art] For example, as shown in FIGS. 8 and 9, when constructing a bridge using concrete pillars as supports having a bifurcated watershed section, the bridge whose entirety is designated by the reference numeral 1 is , a main body 2 used as a road, a base 3.3 that supports this main body 2, and a support 4 formed above the base.
．． 4, and wires 5 for supporting the pillars 4.4. Here, the support 4 is fixed at tI! by lifting the main body 2 with the wire 5... It was formed to strengthen the #I structure of J1 and improve the overall beauty of Tachibana.

For pillar 4, either build a steel frame and pour concrete, or
Alternatively, it may be formed by pouring reinforced concrete without assembling a steel frame, and its shape is shown in Fig. 9. In FIG. 9, the strut 4 has left and right legs 6.7 extending diagonally, and a portion where the legs 6.7 meet, in other words, it is divided into two parts. It consists of a vertical part 9 that is vertically connected to the 9th part.
In the figure, the plurality of wires 5... are not shown.

To form the pillar 4, first, steel frames are assembled into a predetermined shape corresponding to the shape of the pillar 4, and then concrete is poured, or concrete is poured by implanting reinforcing bars without assembling the steel frame. When pouring concrete here, conventionally it was necessary to erect a gigantic scaffold that would surround the entire pillar in order to install the formwork, and then pour the concrete.

However, constructing a huge scaffolding that surrounds the entire pillar requires a great deal of effort. Moreover, most of the work for assembling the scaffolding is done manually, resulting in high labor costs, and as a result, the cost for forming the pillars 4 also increases.

On the other hand, as shown in FIG. 3A, for example, a scaffold 10 of a fixed length is constructed so that it can be moved by pushing it up from below (in the direction of the arrow in FIG. 3A), and concrete is attached to a pre-assembled steel frame. or pour reinforced concrete without assembling the steel frame, then push the scaffolding 10 upwards by a certain distance, set formwork on the upper steel frame part and pour concrete, or cast concrete on the upper part. Technology for placing reinforced concrete (so-called climbing up method)
is proposed. This climbing up construction method is suitable for concrete pouring of vertically extending columns, since it is not necessary to assemble a huge scaffold that surrounds the entire column 4 during construction.

However, when using the climbing up method, although it is possible to construct a single vertically extending concrete column, it is difficult to construct a concrete column that has a bifurcated branch section 8 as shown in Figure 9. As shown in FIG. 1A, below the diversion section 8, the scaffold 10A inside the scaffold 10 for the leg section 6 (the leg J% on the side facing the leg section 7) and the leg Scaffold 1 inside scaffold 11 for section 7
1A and interfere with each other, making it impossible to lift the scaffolds 10 and 11 higher than that.

For this reason, when forming a column having a bifurcated flow branch, it has conventionally been necessary to assemble a scaffold that surrounds the entire column, even though the work cost is high.

[Object of the Invention] The present invention was proposed in view of the above-mentioned shortcomings of the prior art. The object of the present invention is to provide a concrete column forming method that enables concrete pouring work for columns having a diversion section.

[Structure of the Invention] The concrete column forming method of the present invention is a method for forming a concrete column having a bifurcated part, which includes:
The process of pouring concrete while gradually pushing the scaffolding upwards along the legs of the concrete pillars, and
a step of assembling a connecting scaffold above the part where the scaffolds merge and pushing up the scaffolding on the outside of the leg; and a step of pouring concrete in the diversion area surrounded by the connecting scaffold and the scaffolding on the outside of the leg. The method includes the step of gradually pushing up the scaffolding on the outside of the legs along the vertical part above the diversion part and pouring concrete into the vertical part.

[Operations and Effects of the Invention] The present invention is an improvement on the climbing up method in which concrete is poured while gradually pushing the scaffolding upwards, and as a result, there is no need to assemble a huge scaffolding that surrounds the entire pillar. In addition, according to the present invention, only the scaffolding on the outside of the legs is pushed upward at the diversion section, and the scaffolding on the inside of the legs joins above the part where the scaffolds on the inside of the legs join. By assembling the connecting scaffolding, it becomes possible to pour concrete into the bifurcated watershed. As a result, the labor and costs involved in forming a concrete column with bifurcated sections are significantly reduced compared to conventional construction methods.

[Preferred Embodiment] When implementing the present invention, a steel frame may be assembled in advance, and concrete may be poured while gradually pushing the scaffolding upward along the steel frame, or the steel frame may not be assembled. Reinforced concrete may be placed.

Further, when pushing the scaffolding upward, it is preferable to attach a rail to the poured concrete so that the scaffold moves along the rail.

Furthermore, it is preferable to use jacks and locking means as means for pushing the scaffold upward.

Here, the locking means may be of a type that combines a cam driven by a hydraulic cylinder and a link Fsf/N, or a type that combines a wedge-shaped chamber driven by a hydraulic cylinder and a link i oak. Preferably.

In addition, in order to provide a safe and highly efficient scaffold for both the legs extending in the fl direction and the vertical part extending vertically, it is preferable to install turnbuckles on two adjacent sides of the scaffold. .

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

To form a concrete support 4 as shown in Fig. 9, as described above, first assemble the steel frame into a predetermined shape, then pour concrete from below the steel frame, or cast reinforced concrete without assembling the steel frame. The illustrated embodiment does not involve assembling steel frames in advance, but constructs a reinforced concrete structure by planting reinforcing bars and pouring concrete each time. The reference numeral 12 in the figure indicates a reinforcing bar, and the reinforced concrete is placed gradually from below the legs 6.7 toward the diversion section 8.

Figures 3A, 3B, and 3C show the process of pouring reinforced concrete from below the legs to the diversion section while gradually pushing the scaffold upwards along the legs. This process is carried out in substantially the same manner as the conventional climbing up method.

In FIG. 3A, a scaffold 10 is assembled to pour concrete into the legs 6, and below the scaffold 10 (in the direction of the arrow in FIG. 3A), a reinforced concrete C
has already been cast.

The scaffold 10 is constructed by combining a large number of frames, and the longitudinal direction of the legs 6 is divided into seven sections 13.14.15.1.
It is divided into 6.17.18.19. Reinforced concrete has already been placed in these sections, and section 16
．． 17 concrete is in the curing period after being poured.

In each section 13 to 19 of the scaffold 10, turnbuckles 20, 20 and 20 are installed between adjacent frames to prevent the scaffold from deforming due to the weight of the poured reinforced concrete, etc.
... is provided. Incidentally, the reference numeral 21 in Fig. 38 indicates a formwork for concrete.

The scaffolding 10 can be moved along rails 22, 22 attached to a portion where reinforced concrete is cast. A jack 23 is a member that pushes the scaffolding 10 upward and moves it. This jack 23 is shown in Figures 2A and 2B.
It is shown in detail in the figure, and is attached to cast reinforced concrete C by bolts 25.

When performing reinforced concrete placement work for the legs 6, first place the reinforcing bars 12 and place concrete (reinforced concrete After the curing period for the reinforced concrete in section 18.19 has elapsed, concrete is poured in section 16.17.

Further, after the curing period for the concrete in sections 16 and 17 has elapsed, concrete is poured in sections 14 and 15. Thereafter, the entire scaffold 10 is pushed upward (in the direction of arrow H in FIG. 3A) by the jack 23 shown in FIG. 2. Then, after a curing period for the previously placed reinforced concrete has elapsed, a formwork is installed on the steel frame newly surrounded by the scaffolding 10, and reinforced concrete is poured. By repeating the above steps in sequence, reinforced concrete is placed on the legs 6 while gradually pushing the scaffolding 10 upward. Note that the manner in which concrete is poured into the leg portion 7 using the climbing up method is exactly the same as the manner in which concrete is poured into the leg portion 6, so a description thereof will be omitted.

Regarding the manner in which the scaffold 10 is pushed upward, FIG. 4A,
Figure 4B, Figure 4C, Figure 5A, Figure 5B, Figure 6A,
This will be explained in more detail using FIG. 6B, FIG. 7A, and FIG. 7B.

In FIG. 4A, between the scaffold 10 and the rail 22, only a portion of which is shown, a lifting jack 23 and a link tIt 26, 27 for locking the scaffold are provided. In FIG. 4A, the upper link am26 is in a free state (the scaffold 10 is not locked to the rail 22), the lower link tll structure 27 is in a locked state, and the jack 23 is in a contracted state. In order to push the scaffolding 10 upward from this state, the jack 23 is brought into an extended state. That is, by extending the jack 23, the scaffold 10 and the upper link mechanism 26 in the free state are pushed upward (Fig. 4B), and when the jack 23 is extended by a predetermined amount, the upper link IatR2
6 into the locked state. Next, the lower link am27, which is in the locked state, is brought into a free state, and the jack 23 is contracted. Here, since the upper link mechanism 26 is in the locked state, when the jack 23 is retracted, the lower link l1ltl127 moves upward as shown in FIG. 4C.

If the lower link mechanism f7t27 is locked and the upper link mechanism 26 is set free from the state shown in FIG. 4C, the state will be the same as that shown in FIG. 4A. Thereafter, by repeating the above steps, the scaffold 10 can be pushed upward by the required amount.

Top link IH! 26 and the bottom link It'm 2
Various types of configurations can be applied to the configuration for locking the feet of the foot 7 to the rail 22 or releasing the locked state to create a free state. If kept, Figure 5A, Figure 5
In the configuration shown in Figure B, the link machine 41126.27 includes a cam 30 connected to the hydraulic cylinder 29 via the lever 28, a link 31, a friction pad 32 attached to the link 31, and a link mechanism including these. scaffolding 10
It includes a main body part 33 for attachment to the main body part 33. In the free state shown in FIG. 5A, the hydraulic cylinder 29 is contracted and the cam 30 does not press the link node 34 to which the friction pad 32 is attached. On the other hand, in the locked state shown in FIG. 5B, , the hydraulic cylinder 29 is extended, and as a result, the cam 30 rotates 90 degrees clockwise from the state shown in FIG. Since the friction pad 32 frictionally engages with the rail 22,
The scaffold 10 is locked to the rail 22 via the main body 33.

The link mechanism 26, 27 shown in FIGS. 6A and 6B is the fifth
It has a configuration similar to that shown in Figures A and 5B, but
The shape of the link 31A is different. FIG. 6A shows a free state, and FIG. 6B shows a locked state, and since the operation is the same as that in FIGS. 5A and 5B, the explanation will be omitted.

7A and 7B show a link mechanism 26, 27 of a type in which a wedge-shaped camber member 35B is combined with a link 31B.

FIG. 7A shows a free state, in which the hydraulic cylinder 29
B is contracted, and the camber member 35B does not press the link node 34B to which the friction pad 32 is attached toward the reinforced concrete C. However, in the locked state shown in FIG. 7B, the hydraulic cylinder 29B is extended. Since the camber member 35B is pressed forward, the link node 34B is pressed toward the reinforced concrete C. As a result, the scaffold 10 is fixed to the rail 22 via the main body portion 33B.

As the concrete placement work for the legs 6.7 by the climbing up method progresses, the inner scaffold 10A of the concrete casting scaffold 10 for the legs 6 and the legs 6. The outer scaffold 11A of the scaffold 11 of No. 7 merges with the outer scaffold 11A below the diversion section 8 (part 35).
In Figure 8, reference numeral 11B indicates the outside of the scaffold 11 of the leg portion 7.

If the state shown in FIG. 1A is reached, the inner scaffolds 10A and IIA cannot be pushed upward beyond the confluence portion 35. Therefore, as shown in FIG. 1B, only the outer scaffolds 10B and 11B are pushed upward. and assemble the connecting scaffold 36 above the merging portion 35. As a result, the upper end of the leg 6 is surrounded by the scaffolds 10B and 36, and the upper end of the leg 7 is surrounded by the scaffold 36 and 11B, so reinforcing bars 12 are implanted at the upper end of the leg 6.7, and the formwork is It can be installed and concrete can be poured. Then, as shown in FIG. 1C, the outer scaffolds 10B and IIB are further pushed upward, the connecting scaffold 36 is assembled even more tightly, and the formwork is installed.

After that, as shown in FIG. 1D, connecting scaffolds 36 are added in both the left and right directions to increase the width of the lower part of the connecting scaffolds to improve stability, and to connect the branch parts 8 of the columns to the scaffolds 10B, II.
B and connecting scaffold 36. Then, as shown in FIG.
A formwork 37 is installed to match the shape of the lower half. Then, a reinforced cone concrete will be installed in the lower half of the diversion section.

Next, as shown in Fig. 1F, a reinforcing bar 12 is inserted into the upper half of the diversion section 8.
and concrete formwork 38 is installed. Here, its upper half is surrounded by the connecting scaffold 36 and the scaffolds 10B and 11B. Then, by pouring reinforced concrete into the upper part where the formwork 38 is installed, the concrete pouring of the diversion section 8 is completed (Fig. 1G).

Once the reinforced concrete placement work for the diversion section 8 is completed, the reinforced concrete placement work for the vertical section 9 (FIG. 9) above the diversion section 8 is carried out.

Before placing reinforced concrete in the vertical section 9, first, sections 14 and 15 of the scaffolding 10B and IIB are erected vertically as shown in Fig. 1H. Remove the concrete formwork 38 in the part where the curing period has elapsed for assembling the scaffold so as to install a formwork corresponding to the shape of the vertical part 9, and install the scaffolds 10B and 11B on the side of the vertical part 9. push it upward so that it is in the correct position, and install the formwork 39 (1st I
figure).

Then, reinforced concrete is poured. After that, scaffolding 1
The work of placing reinforced concrete in the vertical section 9 is carried out in the same manner as the normal climbing up method, while gradually pushing up 0B and IIB (Fig. 1J, Fig. 1K, Fig. 1L).

[Summary] As explained above, according to the concrete column forming method of the present invention, when forming a column having a bifurcated branch, it is necessary to assemble a huge scaffold that surrounds the entire column. There is no problem, and concrete pouring work can be performed using the characteristics of the so-called climbing up method. Therefore, the labor and cost of constructing such supports can be greatly reduced.

It should be noted that the construction method of the present invention is not only used for forming bridge supports, but can be applied to all cases of forming a structure having a bifurcated watershed.

[Brief explanation of the drawing]

Figure 1A, Figure 1B, Figure 1C, Figure 1D, Figure 1E,
Figure 1F, Figure 1G, Figure 1H, Figure 1I, Figure 1J,
Figure 1K and Figure 1L are a front view and Figure 2, respectively, illustrating how a concrete column is formed by the method of the present invention.
Figures A and 2B are a side view and a front view of the jack used in the embodiment of the present invention, respectively, Figure 3A is a front view showing how the legs of a concrete column are formed using the climbing up method, and Figure 3B is a front view of the jack used in the embodiment of the present invention. The figure is a side view of the legs and scaffolding shown in Fig. 3A, Fig. 3C is a bottom view of the legs and scaffolding shown in Fig. 3A, and Figs. 4A, 4B, and 4C are respectively pushing the scaffold upward. Side view explaining the process, No. 5A
Fig. 5B is a side view, Fig. 6A, and Fig. 6B are respectively illustrative of the link mechanism that locks the scaffolding to reinforced concrete.
The figures are side views explaining other configurations of the link mechanism,
7A and 7B are side views each illustrating the configuration of another link mechanism, FIG. 8 is a front view of a bridge equipped with a support having a bifurcated flow divider, and FIG. It is a front view of the support column in a figure. 4... Support column 6.7... Leg part 8... Diversion part 9... Vertical part 10.11... Leg 1% I
OA, 11A... Scaffolding inside the leg 10B, 11B...
・Scaffolding on the outside of the leg 12...Reinforcing bar 23...Jet 26.27...Link machine 1* 35.
・・Confluence part 36・Connecting legs yR37, 38, 39・
...Formwork whistle Figure 2A Figure 5A Figure 55 Figure 6A Figure bB Figure 7, 41 Figure 78 CIF3

Claims (1)

[Claims] In the construction method of forming a concrete column with a bifurcated branch, the process of pouring concrete while gradually pushing the scaffolding upward along the legs of the concrete column, and the part where the scaffolding inside the legs join together. The process of assembling the connecting scaffold above and pushing the scaffolding outside the leg upwards, the process of pouring concrete in the diversion area surrounded by the connecting scaffold and the scaffolding outside the leg, and the process of placing concrete in the vertical area above the diversion area. A method for forming a concrete column comprising the step of gradually pushing up the scaffolding outside the leg part along the vertical part and pouring concrete in the vertical part thereof.