JP3321702B2 - Construction method of concrete slab, structure of semi-PC slab for slab and concrete slab - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a concrete slab applicable to a tunnel slab, a pavement road, various yards, and the like, and a structure of a semi-PC slab for a slab and a concrete slab.

[0002]

2. Description of the Related Art In the NATM method, concrete (primary lining) is sprayed on a tunnel ground immediately after excavation of an arc portion, but when the geology is unstable, the bottom (inverted portion) is formed. Excavation is done and concrete is separately cast and constructed.

[0003]

However, it takes several days for the primary lining of the inverted part that has been cast in the field to develop strength, and the traffic during that time is severely restricted, so that the work of the face must be interrupted. In addition, there is a problem that the inverted portion tends to bulge during the curing period. It is also possible to use early-strength concrete for the purpose of shortening the curing period,
Nevertheless, not only does it require at least two days of curing time, but there is also a problem that rutting tends to occur.

A method of constructing a tunnel slab using a precast slab has also been proposed. However, when the cross-sectional curvature of the slab changes, it is necessary to manufacture a plurality of types of precast slabs having different curvatures. However, there is a drawback in that the production cost is several times higher than that of a concrete casting site.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a concrete floor slab construction technique capable of opening traffic early and having excellent workability. is there.

[0006]

The invention according to claim 1 is
In the method of constructing a concrete floor slab on the ground, a step of laying a layer of rigid concrete on the ground, and covering the rigid concrete layer while applying vibration to a half-PC slab equipped with a plurality of dowels. It is a construction method of a concrete floor slab characterized by comprising a construction step and a construction step. The invention according to claim 2 is a method of constructing a concrete floor slab on a ground, wherein a step of spreading rigid concrete in a layer on the ground and applying vibration to a half-PC slab equipped with a reinforcing steel bar. And a step of lining the hardened concrete layer. According to a third aspect of the present invention, in the method for constructing a concrete floor slab according to the first or second aspect, a step of laying the hardened concrete in layers and applying a vibration to the half-PC slab is performed. And a step of lining the concrete slab. The invention according to claim 4 is a half slab for floor slabs which is laid on hardened concrete laid in layers on the ground.
A semi-PC version for floor slabs, wherein the C version is a precast version made of concrete, wherein a plurality of dowels are planted on one side of the precast version. Claim 5
The invention according to the present invention relates to a half-PC slab for a floor slab, which is laid on a layer of hardened concrete laid in layers on a ground, is a concrete precast plate, and a reinforcing steel bar is disposed on one surface of the precast plate. Characterized in that the half-P for floor slabs
C version. The invention according to claim 6 is a concrete floor slab formed in the form of a layer, in which a rigid concrete layer is spread and leveled prior to the ground, compacted by applying vibration and compacted. Semi-P lining surface
A concrete floor slab, comprising a C slab and having an integral structure with a hardened concrete layer via a dowel planted in the half-PC slab. The invention according to claim 7 is a concrete slab formed in the form of a layer, in which the rigid concrete layer is spread and laid before the ground, compacted by applying vibration and compacted. Consisting of a semi-PC version coated on the surface,
This is a structure of a concrete floor slab, characterized in that a reinforcing steel bar integrally mounted on a C-slab is embedded in a hardened concrete layer.

[0007]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<A> Configuration of Floor Slab FIG. 1 shows an example of construction of a floor slab 1 for a tunnel. The floor slab 1 is composed of a laminated structure of a hardened concrete layer 2 and a semi-PC version 3 for lining the surface layer of the hardened concrete layer 2.

<B> Hardened Concrete Layer The hardened concrete layer 2 is a well-known hardened concrete with a small amount of water and a slump close to zero. Generally, this kind of hardened concrete is formed into a plurality of layers by roller rolling and vibration compaction, but in the present invention, it is applied in one vibration compaction step as described later.

<C> Half PC version The half PC version 3 is a precast version made of concrete, and has a plurality of dowels 4 implanted on one side thereof. The shape of the half-PC plate 3 is not limited to the illustrated arc-shaped rectangular plate, but is appropriately designed according to the cross-sectional shape of the tunnel. The bevel 4 functions not only as a connecting member for increasing the bonding strength of the half PC plate 3 with the stiffened concrete layer 2 but also as a vibration transmitting member for transmitting vibrations to the deep part of the stiffened concrete. Or a bolt-shaped object having an enlarged diameter head or a sharp cone. The half PC version 3 can be manufactured in a hard and high quality in a factory or the like where the environment is well-equipped.

The reason why the present invention uses the half PC version 3 is as follows. For example, simply rolling compacted concrete requires at least several hours of curing time until strength is developed, during which time traffic cannot be opened. Also, when the plate thickness of the floor slab 1 exceeds the plate thickness that can be rolled at one time, or when a large-sized construction machine cannot be introduced, the laying of the hardened concrete and the rolling are repeated a plurality of times. It is necessary and the workability is poor. In addition, if the constancy of concrete is increased by giving priority to workability, the waiting time until opening of traffic becomes longer. As described above, no appropriate construction technology that can achieve early traffic opening has been established.

Accordingly, the present invention enables the early opening of traffic, which has been difficult to achieve, by lining the half-PC plate 3 immediately after spreading the hardened concrete layer 2 and oscillating. It is. This is because the half-PC version 3 is used as the next shared member.

The semi-PC plate 3 functions as a compaction tool (compression tool) including not only the surface layer of the hardened concrete but also the inside of the hardened concrete via the group of dowels 4.

The semi-PC plate 3 functions as a temporary pavement member for dispersing the load on the hardened concrete layer 2 having insufficient strength and preventing the hardened concrete layer 2 from being dug out. I do.

After the hardened concrete layer 2 has hardened,
It functions as a pavement material that is harder than the hardened concrete layer 2 and has less wear and deformation.

[0016]

Next, the construction method of the floor slab 1 will be described.

The ground 5 excavated as shown in FIG.
Spread hardened concrete in layers. Since the plate thickness of the hardened concrete layer 2 decreases due to compaction, only the amount that allows for this reduction is provided.

An installation frame 7 equipped with an exciter 6 is connected to a backhoe (not shown) or the tip of an arm of a dedicated machine so that the swing angle in all directions can be adjusted. Then, the installation frame 7 is temporarily fixed integrally to the inside of the pre-manufactured half PC plate 3 with bolts or the like. This half-PC plate 3 is covered on the surface side of the uncured hardened concrete layer 2. At this time, the vibrator 6 is operated to vibrate the hardened concrete layer 2 via the half-PC plate 3 to compact it.

In the conventional roller compaction method, the plate thickness that can be compacted by one compaction operation is limited to a small thickness. In contrast, in the present invention, vibration can be applied to the deep portion of the hardened concrete layer 2 through the group of dowels 4, so that the thickness of the hardened concrete layer 2 that can be compacted via the half PC plate 3 increases.
The floor slab 1 is spliced while repeating the above steps.

The adjacent half PC plates 3 may be fastened with bolts as in a known tunnel segment.
You may leave it as it is.

Here, the characteristics of the floor slab 1 will be verified.
Immediately after the lining of the half PC plate 3, the hardened concrete layer 2
Can be used for traffic opening even if the strength is not sufficiently developed. This is to prevent the half PC plate 3 from dispersing the load of the traffic vehicle and partially concentrating the load on the stiff concrete layer 2.

After the curing period, the hard half-PC plate 3 not only protects the hardened concrete layer 2 to release the hardened concrete layer 2 from abrasion but also reduces the wear of the half-PC plate 3 itself. Less is needed.

It goes without saying that secondary lining may be performed by casting concrete on the floor slab 1.

[0024]

[Embodiment 2] The floor slab 1 of a tunnel has been described above as an example. However, the present invention is also applicable to pavement of general roads. For example, when applied to areas where roads with heavy traffic tend to be rutted, or to intersections and bus stops where vehicles stop and start frequently, not only does the pavement surface wear less, but also compared to conventional pavement methods. There are many advantages such as good repairability and the time to open the traffic significantly earlier than before.

The present invention can also be applied to the pavement of a runway for light aircraft and various yards (ports, storage areas, parking lots, etc.).

[0026]

Third Embodiment FIG. 3 shows another embodiment in which a reinforcing bar 8 is integrally provided on the half PC plate 3. FIG. 3A shows a case where the reinforcing steel bar 8 is integrally fixed to the dowel 4 by welding or the like, and FIG. 3B shows a case where a plurality of support rods 9 are attached to the half PC plate 3 separately from the dowel 4. The reinforcing rods 8 are attached to the support rods 9.
Shows a case where are fixed together. The reinforcing reinforcing bar 8 integrally provided on the half-PC plate 3 is buried by pushing unhardened hardened concrete when the half-PC plate 3 is covered.

In the present embodiment, a part of the reinforcing reinforcing bar 8 is laterally protruded from the half-PC plate 3, and when the half-PC plate 3 is covered, the reinforcing reinforcing bars 8, 8 adjacent to each other are formed. When they are arranged in an overlapping manner, continuity can be imparted to the reinforcing steel bars 8.

In the present embodiment, the reinforcement work of the reinforcing steel bar 8 can be performed simultaneously with the lining of the half PC plate 3, so that the workability is further improved and the strength of the floor slab 1 is further improved. I can do it.

[0029]

According to the present invention, the following effects can be obtained. <A> By composing the floor slab by combining the hardened concrete layer and the semi-PC version, the PC version functions as a strength member and a load dispersing member until the strength of the hardened concrete layer is developed. Deformation of the kneaded concrete layer can be avoided. Therefore, it is possible to open the traffic earlier than a conventional slab in which only hardened concrete is compacted. <B> Vibration applied to the half-PC plate can be applied to the deep portion of the hardened concrete layer via a dowel. Therefore, it is possible to compact the thick plate in a single operation using the half-PC plate. <C> After laying the hardened concrete layer, it is only necessary to lay the half PC plate on the hardened concrete layer while applying vibration, and the workability is excellent. <D> When the present invention was applied to a floor slab (inverted portion) of a tunnel, it was difficult to use hardened concrete due to the limitation of the plate thickness that can be compacted once. Not only is it possible to use kneaded concrete, but it can also effectively prevent the floor slab from bulging during the curing period,
The safety of construction is higher. <E> Conventionally, a method of constructing a floor slab using a precast plate has also been proposed. However, the present invention is more advantageous in terms of both the production cost and the transportation cost of a half-PC plate than this conventional precast plate Excellent economy. <F> If the half-PC version is integrally equipped with reinforcing steel, reinforcing work can be performed at the same time as the half-PC version lining. I can do it.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a construction example of a floor slab with a part omitted.

FIG. 2 is an explanatory view of a construction example of a floor slab partially omitted.

FIG. 3 is an explanatory view of another embodiment in which a reinforcing bar is integrally provided on a half-PC version.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floor slab 2 Rigid concrete layer 3 Semi-PC version 4 Jibel 5 Ground 6 Exciter 7 Installation frame 8 Reinforcing steel 9 Support bar

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-197701 (JP, A) JP-A-3-197702 (JP, A) JP-A-7-97898 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) E21D 11/10 E01C 7/32

Claims (7)

(57) [Claims] 1. A method of constructing a concrete floor slab on a ground, comprising: laying a layer of hardened concrete on the ground in a layered manner; and applying vibration to a half-PC slab equipped with a plurality of dowels. A method of constructing a concrete floor slab, comprising a step of lining a kneaded concrete layer. 2. A method of constructing a concrete floor slab on a ground, comprising: laying a layer of stiff concrete on the ground, and applying vibration to a half-PC slab equipped with a reinforcing steel bar. A method of constructing a concrete floor slab, comprising a step of lining a kneaded concrete layer. 3. The method for constructing a concrete slab according to claim 1 or 2, wherein the stiffened concrete layer is laid while layering the hardened concrete and applying vibration to the half PC slab. A method for constructing a concrete floor slab, characterized by repeatedly performing the steps of: 4. A half slab for a floor slab which is laid on a layer of hardened concrete laid in layers on a ground and is a concrete precast slab, wherein a plurality of dowels are planted on one surface of the precast slab. The half-PC version for floor slabs. 5. A semi-PC plate for a floor slab, which is laid on a layer of hardened concrete laid in layers on a ground and is a concrete precast plate, wherein reinforcing bars are arranged on one surface of the precast plate. The half-PC version for floor slabs. 6. A layered concrete slab, comprising: a stiffened concrete layer spread and leveled prior to the ground, compacted by applying vibration, and a surface layer of the stiffened concrete layer. A structure of a concrete floor slab, comprising an engineered half-PC slab, and exhibiting an integral structure with a hardened concrete layer through a dowel planted in the half-PC slab. 7. A concrete slab formed in a layered form, comprising: a stiffened concrete layer which is spread and leveled prior to the ground, compacted by applying vibration, and a surface layer of the stiffened concrete layer. A structure of a concrete floor slab, comprising a modified half-PC version, wherein reinforcing reinforcing bars integrally provided on the half-PC version are embedded in a hardened concrete layer.