JP2002061498A - Method for constructing top slab section of reinforced concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which the top slab section of a reinforced concrete structure can be constructed with good workability and workers are not forced to work in unnatural postures for a long time at the time of performing reinforcing bar arrangement even when the arrangement is performed at a narrow place covered with sheet piles, etc. SOLUTION: The top slab section 15 of a tunnel is constructed in such a way that upper and lower reinforcing bars 20 and 22 are arranged at prescribed positions and supported by a suspended frame 19 extended downward from a pipe roof 2 which is provided in advance above the top slab section. Then the bottom form and side forms of the top slab section are respectively assembled and concrete is placed in the spaces formed of the forms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a slab of a reinforced concrete structure.

[0002]

2. Description of the Related Art FIG. 5 shows a method of constructing a top plate portion of a reinforced concrete tunnel used for forming an underpass, for example. The tunnel 100 shown here has a roadway 101 in the center and sidewalks 102A on the left and right sides of the roadway 101.
102B are respectively formed. Tunnel 1
Concrete has already been poured into the floor slab 103, the outer wall 104, and the inner wall 105 in the middle in the height direction. The method of constructing the upper portions of the remaining inner and outer walls 104 and 105 and the top plate 106 will be described.
First, a shoring 107 which is also used as a scaffold is assembled at a location to be a road 101 and sidewalks 102A and 102B (FIG. 5).
(I)). After that, a reinforcing bar 108 for embedding is arranged at a predetermined location which is to be an upper portion of the inner wall 105 (FIG. 5B).

Next, a bottom mold 109 of the top plate 106, a mold 110 of the inner wall, and an inner mold 111 of the outer wall are assembled, and the molds 109, 110, 111 are assembled.
Is supported by the support 107 (FIG. 5C). Next, embedding rebars 112 are arranged at predetermined locations on the upper side of the outer wall 104 and at predetermined locations on the top plate 106, respectively (FIG. 5 (d)), and then the outer formwork 113 of the outer wall is assembled (FIG. 5 ( E)). And, those molds 109, 1
Concrete is poured into 10, 111 and 113, thereby forming the top plate 106 and the like.

[0004]

However, the above-mentioned conventional method for constructing the top plate of a reinforced concrete structure has the following problems. In other words, in a normal construction site where the upper and side surfaces of the structure are open, the above construction method can be adopted without any trouble.However, for example, when constructing a tunnel under the track or an underground mall, both the upper side and the left and right sides are used. And the sheet pile 11
When the above-described conventional construction method of assembling the bottom formwork in a narrow place surrounded by 4 or the like and then performing the reinforcing arrangement (see the one-dot chain line in FIG. 5D) is adopted, the formwork 109, 110,1
In the narrow space 115 surrounded by the sheet 11 and the sheet pile 114, the work of transporting the main reinforcements including the upper reinforcement and the lower reinforcement buried in the top plate portion 106 and the operation of installing the main reinforcements must be performed. And the work time is prolonged. In addition, the operator can use the above-described form
Narrow space 11 surrounded by 110, 111 and sheet pile 114
In 5, the user is forced to work in an unreasonable posture to bend his / her waist, which causes a problem that the user feels fatigue earlier than in a normal environment.

The present invention has been made in view of the above circumstances, and has as its object to improve the workability in arranging reinforcing bars even when the upper part is a narrow part surrounded by a sheet pile or the like. It is an object of the present invention to provide a method of constructing a top plate portion of a reinforced concrete structure which can shorten the working time while keeping the work time, and does not force the worker to work for a long time in an unreasonable posture.

[0006]

According to a first aspect of the present invention for solving the above-mentioned problems, when a top plate portion of a reinforced concrete structure is constructed, a reinforcing bar embedded inside the top plate portion is provided. In place, then
It is characterized in that the bottom mold and the side mold of the top slab are respectively assembled and supported by shoring, and then the top slab is made by casting concrete into the molds. The invention according to claim 2 is characterized in that a support is provided in advance above the top plate portion, and the reinforcing bar of the top plate portion is suspended and supported by a suspension base extending downward from the support. The invention according to claim 3 is that, after assembling the bottom formwork of the top plate portion, removing the suspension base extending downward from the support, adjusting the position of the reinforcing bar of the top plate portion, and then forming the formwork. It is characterized by casting concrete inside to make the top slab. The invention according to claim 4 is characterized in that the support is a pipe roof in which a plurality of pipes are arranged in parallel.

According to the present invention, when constructing the top slab of the concrete structure, the arranging work is first performed on the top slab before assembling the formwork. The work can be performed using a wide space on the side, and therefore, even when a sheet pile or the like is previously arranged above the structure, good workability in performing the arrangement of the reinforcing bars can be ensured.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a reinforced concrete structure according to the present invention, in which a tunnel for forming an underpass under a track is being constructed, and FIG. 2 is a front view of the reinforced concrete structure, in which the tunnel is being constructed. In these figures, reference numeral 1 denotes a tunnel for forming an underground passage to be made below the track, and reference numeral 2 denotes a pipe roof for retaining the soil when the tunnel 1 is made. The pipe roof 2 is formed by press-fitting a large number of steel pipes 2a into the ground so as to form a gate shape when viewed from the front. The pipe roof 2 supports the ground to prevent the top end from collapsing. However, tunnel excavation inside is possible. In FIG. 2, reference numeral 3 denotes a girder receiving the pipe roof 2, and 4,...

In the tunnel 1, a road 10 is formed in the center, and sidewalks 11A and 11B are formed on the left and right of the road 10, respectively. In this case, up to the intermediate portions in the height direction of the floor slab portion 12, the outer wall 13, and the inner wall 14 of the tunnel 1,
Concrete has already been cast.

A method of applying the remaining upper portions of the inner and outer walls 14 and 13 and the top plate portion 15 will be described with reference to FIGS. First, a shoring 17 which is also used as a scaffold is assembled at a location to be the road 10 and the sidewalks 11A and 11B (FIG. 3).
(I)). In this case, the shoring 17 is not formed up to the position of the lower end surface 15a of the top plate portion 15, but is formed up to a predetermined height with a predetermined gap 18 provided between the support plate 17 and the lower end surface 15a.

Next, the suspension base 19 is assembled via a stay 19a extending downward from the pipe roof 2 (FIG. 3).
(B)). Thereafter, the upper streak 20 of the top plate 15 is arranged at a predetermined position, and the upper streak 21 is supported by the suspension base 19 (FIG. 3C). Next, a reinforcing bar 21 for embedding is arranged at a predetermined location that is to be the upper portion of the outer wall 13 (FIG. 3D). Thereafter, the lower streaks 22 of the top plate 15 are arranged at a predetermined position, and are not shown. A width stop is stretched between the abdominal muscles, thereby temporarily fixing the entire arrangement of the top plate 15 (FIG. 3E).

Next, a reinforcing bar 23 for embedding is arranged at a predetermined location on the upper side of the inner wall 14 (FIG. 4 (f)). Thereafter, the first assembled support 17 and the lower end face 15 of the top plate portion are formed.
a secondary supporter 17a is assembled on the upper side of the supporter 17 so as to fill the gap 18 between the supporter 17 and the supporter 17 (FIG. 4).
(G)). Further, the bottom formwork 24 of the top slab, the left and right formworks 25 and 25 of the inner wall 14, and the inner formwork 26 of the outer wall are assembled respectively, and these formworks 24, 25 and 26 are attached to the support 1
7, 17a (FIG. 4 (h)).

Next, the suspension gantry 19 supporting the reinforcing bars of the top plate 15 is removed, and the positions of the free reinforcing bars relative to the formwork 24 and the mutual connection of the reinforcing bars are reduced. Perform final position adjustment including the interval (Fig. 4
(Re))

Thereafter, the outer formwork 27 of the outer wall is assembled (FIG. 4 (N)). Next, those molds 24, 25, 26,
Concrete is poured into the inside 27, and after curing for a predetermined period, the formwork 24, 25, 26, 27, the shoring and the like are removed. Through the steps described above, the upper portions of the inner and outer walls 14, 13 where the tunnel is left and the top plate 15 are formed.

According to the above-described method for constructing the top slab of the reinforced concrete structure, the reinforcing work is first performed on the top slab 15 before assembling the bottom formwork 24 and the like of the top slab 15. The reinforcing work can be performed using a wide space below the place where the bottom formwork 24 is arranged,
Therefore, even in the case where the pipe roof 2 is previously arranged above the structure and a work space cannot be taken above the arrangement location as in this example, it is possible to ensure good arrangement workability. it can. For this reason, even when the working space cannot be taken upward, the construction period is much longer than in the case of adopting the construction method of assembling the formwork 24 of the top slab first and then performing the reinforcing work. Shortening is possible.

The bar arrangement work for the top plate 15 is as follows.
It can be performed using a wide space below the place where the bottom formwork 24 is arranged. Specifically, the worker can perform the rebar arrangement work in a standing posture in which the worker places his foot on the intermediate position of the supporter 17 also serving as a scaffold. For this reason, the work in an unreasonable posture performed by bending the waist as described in the conventional example is shown in FIG.
It only stops at the final bar arrangement shown by. As a result, the physical burden on the worker is reduced in each step as compared with the case where the conventional construction method is adopted.

Further, as described above, the bottom formwork 24 of the top plate portion is formed.
Is a construction method of assembling after the reinforcing work and before the concrete is finally poured, and it is difficult for dust such as reinforcing bars and scales to collect on the surface of the bottom formwork 24. The cleaning work of the formwork surface before the concrete is poured becomes unnecessary.

It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately designed and modified without departing from the spirit of the invention. For example, in the above-described embodiment, the present invention has been described by exemplifying a case where a top plate portion of a tunnel under a track is constructed. However, the present invention is not limited to this. It goes without saying that the present invention can be applied to the case of making a top plate portion of another reinforced concrete structure.

[0019]

According to the first aspect of the present invention, before the bottom formwork or the like of the top slab is assembled, the reinforcing work is performed on the top slab first. Can be performed using a large space below the place where
Therefore, it is possible to ensure good workability of rebar arrangement, and when the work space cannot be secured above the rebar arrangement part, adopt the conventional construction method of performing rebar arrangement work after assembling the bottom formwork and the like. The construction period can be greatly shortened compared to Also,
The work in an unreasonable posture, in which the worker bends the waist when making the top slab, can be stopped in only a small part of the entire process, so the physical burden of the worker is reduced by the conventional construction method. It is reduced to each stage as compared with the case of adoption. Furthermore, since this is a construction method in which the bottom formwork of the top slab is assembled after the rebar work and before the concrete is finally cast, dust such as reinforcing bars and scales may be found on the surface of the bottom formwork. It hardly accumulates, and the work of cleaning the surface of the formwork before concrete casting, which is usually performed, becomes unnecessary. Further, if a support is provided in advance above the top plate portion and the reinforcing bar of the top plate portion is suspended and supported by a suspension base extending downward from the support, the top plate before assembling the formwork of the top plate portion. The reinforcing bar can be supported with the work space left below, and the reinforcing work and the formwork performed in the post-process can be performed while securing good workability. Also, after assembling the bottom formwork of the top slab, if the suspension base extending downward from the front support is removed and the position of the reinforcing bar of the top slab is adjusted, the relative distance between the formwork and the reinforcing bars can be adjusted. The final position error can be finally corrected. Furthermore, if the support is a pipe roof in which a plurality of pipes are arranged in parallel, the existing pipe roof can be effectively used, and the number of parts and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a reinforced concrete structure according to the present invention, which is in the middle of construction when a tunnel for forming an underpass under a railway track is formed.

FIG. 2 is a front view in the middle of construction when making the tunnel.

FIG. 3 is a side view for explaining steps of a method for constructing a top plate portion and the like of the tunnel.

FIG. 4 is a side view for explaining the steps of the method for constructing the top plate and the like of the tunnel.

FIG. 5 is a side view illustrating steps of a conventional method of constructing a top slab of a reinforced concrete structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel 2 Pipe roof (support) 12 Slab part 13 Outer wall 14 Inner wall 15 Top slab part 17 Support 19 Suspension stand 19a Stay 20 Top slab top streak 22 Top slab bottom streak 24 Bottom mold of top slab Frame 25 Side form of inner wall 26 Inner form of outer wall 27 Outside form of outer wall (side form of top slab)

Continuing from the front page (72) Inventor Hiroyuki Yamauchi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Kazuhiko Koshida 1-2-3 Shibaura, Minato-ku, Tokyo Shimizu Corporation F term (reference) 2D054 AB05 AC15 AD23 2D055 BB03 CA06 DA01 GA07 KB08

Claims (4)

[Claims] When constructing a top slab of a reinforced concrete structure, a reinforcing bar embedded inside the top slab is disposed at a predetermined position, and then a bottom formwork and a side formwork of the top slab are removed. A method of constructing a slab portion of a reinforced concrete structure, comprising assembling each of the slabs and supporting the slabs with supports, and then casting concrete into the slabs to form a slab portion. 2. A support is provided in advance above the top plate portion,
The method according to claim 1, wherein the reinforcing bar of the top slab is suspended and supported by a suspension base extending downward from the support. 3. After assembling the bottom formwork of the top slab, the suspension base extending downward from the support is removed, and the position of the reinforcing bar in the top slab is adjusted. 3. The method for constructing a top plate of a reinforced concrete structure according to claim 2, wherein the top plate is formed by casting. 4. The method according to claim 2, wherein the support is a pipe roof in which a plurality of pipes are arranged in parallel.