JP3554937B2 - Construction method of pillars - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for constructing pillars such as piers and pillars of a rigid-frame viaduct.
[0002]
[Prior art]
Bridge piers such as railway viaducts and bridges are constructed by so-called cast-in-place using formwork, but because it takes a long construction time and requires a lot of support and formwork, and requires a lot of labor, There is a need for a proposal for a technology that can be used in place of on-site hitting.
As an improvement technique, for example, a method of introducing a prestress into the whole after stacking blocks divided into a plurality of piers, or applying a precast cast method used in the construction field to a pier and manufacturing it at a factory etc. A method has been proposed to transport the completed piers and install them on the site.
[0003]
[Problems to be solved by the invention]
The above-mentioned pier construction technology has the following problems.
[0004]
<B> Since the direction of load acting on the pier during an earthquake is not constant, it is necessary to design the pier with high strength to withstand the sum of the compressive stress due to prestress and the compressive stress due to load. Although the energy absorption rate is low, the economic burden is large.
[0005]
<B> If the blocks of the pier are stacked while joining a plurality of PC steel materials, the joining process of each PC steel material is troublesome.
[0006]
<C> In the method of installing a pier that has been manufactured in advance, since the column section of the pier is generally large, large heavy equipment is required for transportation and installation, and there is room for improvement in terms of workability and safety.
[0007]
[Object of the present invention]
The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a method for constructing a columnar material having excellent workability and economy.
[0008]
[Means for solving the problem]
According to the present invention, a block having a columnar cross section is stacked with an adhesive layer interposed therebetween, and a main reinforcing bar is continuously inserted between the blocks, and a solidifying material is injected between the block and the main reinforcing bar. This is a method of constructing a columnar object, in which a columnar object made of reinforced concrete is constructed.
[0009]
Embodiment 1
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
<I> Planting process of main rebar
In FIG. 2, reference numeral 1 denotes a concrete foundation on which a deformed main reinforcing bar 2 is planted at a predetermined interval.
The main reinforcing bar 2 is to be planted at the time of constructing the concrete foundation 1 or by drilling or the like after the construction, and the main reinforcing bar 2 has a length corresponding to the height of the pier to be constructed, or A divided body having a length equal to or greater than the height of a plurality of block bodies to be described later may be extended using welding, a connector, or the like.
[0012]
<B> Block stacking process (Fig. 2)
[0013]
Next, a block 3a manufactured in advance at a factory or the like is inserted into the main reinforcing bar 2 in a hierarchically cut shape of the pier, and is mounted on the concrete foundation 1.
The block body 3a is a reinforced concrete divided body formed according to the cross-sectional shape of the pier. The block body 3a has a plurality of through holes 31 pierced at the insertion position of the main reinforcing bar 3, and a corrugated sheath is provided in each through hole 31. 32 are integrally fixed.
The height (weight) of the block body 3a is determined in consideration of transportability and handleability.
If the inner peripheral surface of the through hole 31 is formed to have a different diameter or irregularities, the sheath 32 may be omitted.
Next, after the adhesive layer 4 is formed on the upper surface of the block 3a, a separate block 3b is mounted on the upper surface of the block 3a.
At this time, the main reinforcing bar 2 projecting from the lower block 3a is inserted into the through-hole 31 to mount the block 3b.
A commercially available adhesive having an adhesive strength greater than the adhesive strength of concrete can be used for the adhesive layer 4.
Hereinafter, similarly, the steps of forming the adhesive layer 4 on the upper surface of the block body 3b and the step of mounting the block body 3n by penetrating the main reinforcing bar 2 and mounting the same are repeated to a predetermined height.
[0014]
<C> Step of crimping the block (Fig. 3)
[0015]
A nut 6 is screwed onto the main reinforcing bar 2 projecting from the uppermost block body 3x via a seat plate 5, and the blocks 3a, 3b, 3n... 3x are simultaneously tightened, and the respective blocks 3a, 3b are tightened. , 3n... 3x are more firmly pressed and bonded.
When the adhesive layer 4 has hardened, the nut 6 is removed, and the crimping force introduced between the blocks 3a, 3b, 3n... 3x is released.
The crimping means for the blocks 3a, 3b, 3n... 3x may use the own weight of the blocks 3a, 3b, 3n.
The step of pressing the block body is not essential and may be omitted in some cases.
[0016]
<D> Injection of consolidated material (Fig. 1)
[0017]
Utilizing the through holes 31 of the lowermost block 3a, a solidifying material 7 such as mortar or concrete is injected into a sheath 32 arranged continuously, and the respective blocks 3a, 3b, 3n... 3x is integrated to obtain a reinforced concrete pier 3.
The adhesive layer 4 serves to close the joint of each block constituting the bridge pier, prevent rust prevention of the main reinforcing bar 2 due to water infiltration, and also to avoid the occurrence of stress concentration at the joint of each block.
[0018]
<E> Consideration on the performance of piers
The performance of the pier joined in the above process will be examined.
FIG. 4A shows a test piece of the pier 3 manufactured by joining the two block bodies 3a and 3b in the above-described process.
A pier having the same dimensions as the specimen A was integrally cast to produce a reinforced concrete specimen B (not shown), and a bending test was performed on each of the specimens A and B under the same conditions as shown. FIG. 5 shows the test results.
According to FIG. 5, the bending characteristics of the specimen A in which the precast block bodies 3a and 3b are joined are almost the same as those of the specimen B manufactured by casting concrete integrally, and there is no significant difference in performance. Was proved.
[0020]
Embodiment 2
Recesses and protrusions having irregular shapes may be formed on the upper and lower surfaces of the block, and the blocks may be stacked by fitting the recesses and protrusions.
According to this embodiment, it is possible to obtain an advantage that the shear resistance of each block body is increased by the fitting of the concave portion and the convex portion, and the bonding area of each block body is increased, so that a strong pressure bonding can be achieved.
[0021]
Embodiment 3
The main reinforcing bar 2 may be set after each block is stacked, or the step of injecting the solidifying material 7 may be performed in parallel with the operation of stacking each block.
[0022]
【The invention's effect】
Since the present invention has been described above, the following effects can be obtained.
[0023]
<B> Since a block body, which is a divided body of columnar objects, is used, a large heavy machine is not required for construction.
In particular, it can be easily constructed even if the columnar object has a large cross section.
[0024]
<B> Since the main rebar penetrates the block body and plays the role of a pillar, it does not require support such as stay wires.
[0025]
<C> By interposing an adhesive layer having an adhesive strength greater than the adhesive strength of concrete between the block bodies, it is possible to effectively prevent cracks from occurring between the joints, and to prevent the main reinforcing steel from being flooded from the joints. Corrosion can also be prevented.
[0026]
<D> A columnar material in which each block is integrated with the main reinforcing bar by injecting a consolidating material into the through hole of each block is obtained.
This columnar structure can ensure the same performance as that of concrete integrally cast, and is more economical than the PC structure.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a pier according to the present invention. FIG. 2 is an explanatory view of a step of stacking block bodies. FIG. 3 is an explanatory view of a crimping step of a block body. FIG. 4 is an explanatory view of a bending test of a specimen. FIG. 5 is an explanatory diagram of a bending test result of a specimen.

Claims (3)

While stacking the block body having the cross-sectional shape of the columnar object with the adhesive layer interposed, the main reinforcing bar is continuously inserted between the block bodies,
After tightening and crimping between the block bodies,
Constructing a reinforced concrete column by injecting a binder between the block body and the main reinforcing bar from the lowermost block body,
Construction method of pillars. While stacking the block body having the cross-sectional shape of the columnar object with the adhesive layer interposed, the main reinforcing bar is continuously inserted between the block bodies,
After tightening and crimping between the block bodies, the introduced crimping force is released,
Constructing a reinforced concrete column by injecting a solidifying material between the block body and the main rebar,
Construction method of pillars. In the method for constructing a columnar object according to claim 2 ,
Injecting the consolidated material from the lowermost block body,
Construction method of pillars.

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