JPH057520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a reinforcing bar support and a method of constructing a rock wall surface using the reinforcing bar support.

[Conventional technology]

In recent years, the mainstream construction method used for excavating underground tanks, tunnels, etc. is to use shotcrete and rock bolts as the main supporting members, and utilize the bearing capacity of the ground.

By the way, it is important to increase the rigidity of the supporting material, to stabilize the face until the supporting function of shotcrete and rock bolts is activated, and to support the face with steel pipes, steel sheet piles, etc. When a fulcrum was required, steel supports such as H-beams were often used.

[Problem to be solved by the invention]

However, in the case of conventional steel shoring using H-beams, etc., the shotcrete does not flow sufficiently around the back and wave parts, so if the shoring and shotcrete are integrated into an integrated structure. Moreover, it was not compatible with the secondary lining concrete, and the connection between adjacent shotcrete concrete, which was sequentially applied to the required length in the length direction of the tunnel, was insufficient.

Furthermore, steel shoring using H-shaped steel has the problem that it is not easy to bend on site due to its shape, and the steel pipes or sheet piles used for receiving the tip of the face do not use the steel shoring as a fulcrum. In order to
A hole must be made in the wave of the H-shaped steel for the steel pipe, etc. to be inserted, or it must be cast onto the upper flange. As a result, the insertion angle becomes large, resulting in an increase in overcutting, resulting in a problem of poor workability.

Nono's invention provides a method for constructing a ground wall surface using a shoring and a shoring, which improves the coverage of shotcrete, integrates the concrete and shoring into an integral structure, and obtains sufficient strength, and also has excellent workability. It is intended for the purpose of providing.

[Means for solving problems]

In the first invention, a reinforcing bar support is fixed to three or more main reinforcing bars placed in related positions such as at each corner of a polygonal cross section, and both ends of these main reinforcing bars are connected to each other. It is formed from a pair of fixing members and a reinforcing member that connects the main reinforcing bars to each other, and the reinforcing member is fixed to each of the main reinforcing bars by welding to connect the main reinforcing bars to each other,
In addition, the reinforcing member is welded to at least one of the main reinforcing bars so that the reinforcing member is welded inside the main reinforcing bar in a space surrounded by each main reinforcing bar, and the reinforcing member is welded to at least one of the main reinforcing bars at a desired position. They are arranged at intervals that allow them to be deformed into shapes.

The second invention is a method for constructing a rock wall, in which the rock wall is stabilized using the reinforcing steel support constructed as described above, and then concrete is sprayed to support the rock.

In addition, the third invention uses the above-mentioned reinforcing bar support to stabilize the ground wall surface, cover and protect the main reinforcing bars on the inner side of the reinforcing bar support, then spray concrete, and then remove the covering and expose them. This is a method of constructing a ground wall in which distribution bars are attached to the main reinforcing bars, and then concrete is poured.

〔Example〕

1 to 5 show an embodiment of the present invention. First, a reinforcing bar support 1 is prepared. This reinforcing bar support 1 consists of three deformed reinforcing bars (main reinforcing bars) 1
a are arranged so that they extend parallel to each other in the length direction so that the cross sections are located at the corners of a substantially triangular shape, and both ends of each deformed reinforcing bar 1a are welded or the like. Rectangular fixing member 1b
The three deformed reinforcing bars 1a are connected to each other by a reinforcing member 1c.

The reinforcing member 1c has a pair of connecting members 1d bent into a triangular shape, which are tilted into a mountain shape.
After forming the reinforcing bar support, the three deformed reinforcing bars 1a are connected to each other by welding or the like, with a sufficient gap between each reinforcing member to allow bending and deformation of the main reinforcing bars into a desired shape. It is composed of That is, in the embodiment, the reinforcing member 1c is fixed to each deformed reinforcing bar (main reinforcing bar) 1a by welding to connect the deformed reinforcing bars 1a to each other. As shown in FIGS. 1 to 4, the welding position of the reinforcing member 1c is
The deformed reinforcing bars 1a are welded so as to be inscribed inside each deformed reinforcing bar 1a in a space surrounded by .

In addition, the connecting members 1d are arranged at equal intervals in the direction of the main reinforcing bars as shown in Figs. 1 and 2, and are deformed so as to come into contact with the ground. This makes it easy to bend and deform when necessary, making it easier to blend into the ground.

That is, this reinforcing bar support 1 uses three deformed reinforcing bars 1a, and the welding position of the reinforcing member to each main reinforcing bar is inscribed inside the deformed reinforcing bars within the space surrounded by each deformed reinforcing bar. By welding in this shape, the restraining force of the reinforcing members against the bending deformation of the deformed reinforcing bars themselves is reduced, and the various reinforcing members are spaced sufficiently apart to prevent them from becoming rigid like a truss structure. , conventional H
Compared to steel shoring using shaped steel, it is easier to deform by bending to suit the wall shape of the tunnel ground 2, and the deformed reinforcing bars 1a include
Since the shotcrete 9 described later is completely attached, the deformed reinforcing bars 1a and the shotcrete 9
and become an integrated structure. Furthermore, by changing the rigidity, spacing, etc. of the deformed reinforcing bars 1a or reinforcing members 1c depending on the strength of the ground 2 and the wall shape of the tunnel ground 2, the rigidity of the reinforcing bar support 1 can be adjusted arbitrarily within a deformable range. It can be easily changed and adjusted.

As shown in FIG. 1, the reinforcing bar support 1 configured in this manner has two deformed reinforcing bars 1a in contact with the wall surface of the ground 2, and the fixing members 1b are brought into contact with each other, and the fixing members The ground 2 is temporarily stabilized by inserting bolts or the like into two or more holes 1e provided in the hole 1b and sequentially connecting the whole wall surface of the ground 2 of the tunnel. In this case, if the shape of the tunnel's ground is extremely deformed compared to the standard cross section, the reinforcing bar support 1 may be bent in advance to match the wall shape of the tunnel's ground 2. It is necessary to deform it by doing so.

Depending on the ground, if necessary, the reinforcing steel supports 1 erected at required intervals in the length direction of the tunnel are installed at both ends of the U-shaped tie bolts 8. They are connected to each other by being inserted into pipes 8a provided on the sides of the deformed reinforcing bars 1a on the ground 2 side of the reinforcing bar support 1. Note that the tie bolts 8 are installed between the reinforcing steel supports 1.
In addition, by disposing a wire mesh made of wire rods vertically and horizontally along the ground 2, the adhesion and strength of shotcrete 9, which will be described later, to the ground 2 can be made sufficient.

Furthermore, the deformed reinforcing bar 1a located on the inner space side is cut in the length direction of the rubber hose 3 and inserted into the rubber hose 3 through a fitting groove provided, thereby covering and protecting the deformed reinforcing bar 1a from adhesion of shotcrete. (Figure 2). Here, since the reinforcing member 1c is welded so as to be inscribed inside the deformed reinforcing bar 1a, the reinforcing member 1c does not get in the way when the rubber hose 3 is mounted over the deformed reinforcing bar 1a. Workability becomes extremely good. That is, for example, if a reinforcing member such as reinforcing bar is welded to the deformed reinforcing bar 1a wrapped around it from the outside, the reinforcing member may get in the way when the rubber hose 3 is placed over the deformed reinforcing bar 1a. Therefore, it is necessary to cut the rubber hose 3 short to a length corresponding to the spacing between the reinforcing members and then cover it. 3
can be used to cover the deformed reinforcing bars 1a at once.

In addition, depending on the situation of the ground 2, a steel pipe 4 for advance receiving is installed.
is inserted between the deformed reinforcing bars 1a on the hollow side of the reinforcing bar support 1 and the deformed reinforcing bars 1a on the ground 2 side, and is driven into the ground 2 from the face 2a along the outer periphery of the excavation cross section. Stabilize the rock wall surface prior to excavation (3rd step)
figure). Therefore, in the case of steel shoring using conventional H-shaped steel, it is necessary to make a hole in the wave part of the H-shaped steel to insert the steel pipe 4 in order to reduce the insertion angle of the steel pipe 4. However, in the reinforcing bar support 1 of the present invention, reinforcing bars are used to create a large space and the degree of freedom of the steel pipe 4 is increased, so there is no need for processing such as drilling holes, and the insertion angle can be freely selected. As a result, overall workability is excellent.

Further, in order to reinforce the ground 2 if it is soft, lock bolts 5 are driven into the ground 2 to stabilize the ground 2 together with the reinforcing steel support 1 (FIG. 4). For example, lock bolts 5 may be driven into two deformed reinforcing bars 1a on the side of the earth 2 from above rectangular expanded metal or plates 6. This expanded metal or plate 6 has one end attached to one deformed reinforcing bar 1a on the ground 2 side.
At the same time, attach the other end to another deformed reinforcing bar 1.
The other end is bent with a fixing bolt 7. In addition, as shown in FIG. 7, the expanded metal 6a is folded in half into a U-shape,
The bent portion may be hooked to the deformed reinforcing bar 1a on one side, and the open end on the other side may be fixed with a fixing bolt 77a. Incidentally, since the lock bolts 5 are for reinforcing the ground 2, they do not necessarily have to be used in combination with the reinforcing steel support 1, and may be driven into the support as appropriate.

Next, shotcrete 9, which will become the primary lining concrete, is applied to the ground 2 and the reinforcing steel support 1.
The reinforcing bar support 1 is constructed to a position approximately halfway between the deformed reinforcing bars 1a on the ground 2 side and the deformed reinforcing bars 1a on the hollow side. In this state, the shotcrete 9 goes to the back side of the expanded metal 6 to form the primary lining concrete, so the reinforcing steel support 1, the lock bolts 5, and the shotcrete 9 form an integral structure with the ground 2. . Shotcrete 9
After solidifying, the exposed inner hollow side deformed reinforcing bar 1
Remove the rubber hose 3 from a, as shown in FIG. Orthogonal and deformed reinforcing bars 1
Secondary lining concrete 12 is formed by installing main reinforcing bars 11 in parallel to a. That is, since the above-described deformed reinforcing bars 1a on the inner space side are exposed to the inner part of the shotcrete 9, the deformed reinforcing bars 1a do not just serve as fixing fittings for the distribution bars 10a of the secondary lining concrete 12. Shotcrete 9 for primary lining concrete and secondary lining concrete 1 act as a binder for poured concrete.
2 are completely integrated to form a composite structure with excellent strength.

In the above embodiment, the reinforcing bar support 1 was formed using three deformed reinforcing bars 1a and was applied to a tunnel. It may be applied to space excavation, round steel may be used as the main reinforcing bars, or four or more deformed reinforcing bars may be used. In the case of four or more deformed reinforcing bars, the shape of the reinforcing member will naturally be changed accordingly.

〔Effect of the invention〕

As explained above, in this invention, since the reinforcing bar support is formed by three or more main reinforcing bars, the shotcrete is sufficiently spread around the back side, and the rock bolts, the reinforcing bar support, the shotcrete, and the ground are integrated. Not only does this result in a structure of the same size, but it also provides a sufficient connection between adjacent shotcrete pieces that have been successively constructed to the required length in the lengthwise direction of the tunnel. In addition, it is easy to bend according to the shape of the earth wall surface, and the number of bolts required to connect the shoring to each other is small due to the fixed members that connect the main reinforcing bars to each other.In addition, the arch action allows for load transmission. This is done evenly between each main reinforcing bar, so it is easy to follow the deformation of the shoring. Moreover, even when driving a steel pipe into the tip of the face, there is no need for any machining, resulting in excellent workability. After erecting this reinforcing steel support, the main reinforcing bars on the inner side are covered and protected with hoses, etc., then shotcrete is applied, and then the hoses are removed and the main reinforcing bars are removed. Because it is exposed, the main reinforcing bars on the inner side act as fixing fittings for the distribution bars of the secondary lining concrete, and also serve as a binding material for the secondary lining concrete, so the shotcrete and secondary lining concrete are completely connected. It has the advantage of being able to be integrated into a composite structure with excellent strength. Further, according to the present invention, the welding position of the reinforcing member to at least one of the main reinforcing bars is such that the reinforcing member is inscribed inside the main reinforcing bar within the space surrounded by each main reinforcing bar. Not only can the restraining force of the reinforcing member against the bending deformation of the reinforcing bars be weakened, making it easier to bend and deform the main reinforcing bars from this point of view, but also the reinforcement member It does not get in the way, and therefore the workability can be made extremely good. That is, for example, if a reinforcing member is welded so as to surround the main reinforcing bar from the outside, the reinforcing member will get in the way and will not be able to cover the main reinforcing bar with a rubber hose. This requires cutting the rubber hose short to a length corresponding to the spacing between the reinforcing members and then covering the reinforcing members with each other. However, in the present invention, the length of the rubber hose between the fixed members is used to connect one main reinforcing bar. It has excellent effects such as being able to cover the entire surface at once.

[Brief explanation of the drawing]

Figures 1 to 6 show one embodiment of the present invention. Figure 1 is a perspective view showing a state in which a reinforcing steel support is erected, and Figure 2 is a perspective view showing a state in which a rubber hose is covered with a steel support. A perspective view, Fig. 3 is a front view showing the state in which the steel pipe is driven into the face, Fig. 4 is a front view showing the state in which the expanded metal is attached, Fig. 5 is its detailed sectional view, and Fig. 6 is the secondary FIG. 7 is a sectional view showing a state in which lining concrete has been sprayed, and FIG. 7 is a sectional view showing a modified example of the state in which expanded metal is attached. 1...Reinforcing bar support, 1a...Deformed reinforcing bars (main reinforcing bars), 1b...Fixing member, 1c...Reinforcement member, 2
...Ground, 2a...Face, 3...Rubber hose, 4
...Steel pipe, 9...Shotcrete.

Claims (1)

[Scope of Claims] 1. Three or more main reinforcing bars that extend parallel to each other in the length direction and are arranged in related positions such as being located at each corner of a polygonal cross section, and both ends of these main reinforcing bars are connected to each other. a pair of fixing members connected and fixed;
A reinforcing bar support is constructed by a reinforcing member that connects each of the main reinforcing bars to each other, and is constructed by bending and deforming each of the main reinforcing bars so as to follow the shape of the wall surface of the excavated ground, the reinforcing member comprising: The reinforcing member is fixed to each main reinforcing bar by welding to connect the main reinforcing bars to each other, and the welding position of the reinforcing member to at least one of the main reinforcing bars is within the space surrounded by each main reinforcing bar. The reinforcing bar support is welded so as to be inscribed inside the reinforcing bars, and further, the reinforcing members are arranged at intervals such that each of the main reinforcing bars can be bent and deformed into a desired shape. 2 Three or more main reinforcing bars that extend parallel to each other in the length direction and are arranged in related positions such as at each corner of a polygonal cross section, and both ends of these main reinforcing bars are connected and fixed to each other. a pair of fixing members;
a reinforcing member that connects the main reinforcing bars to each other, the reinforcing member is configured to be fixed to each of the main reinforcing bars by welding to connect the main reinforcing bars to each other, and at least one of the main reinforcing bars The welding position of the reinforcing member is inscribed inside the main reinforcing bar in a space surrounded by each main reinforcing bar, and the reinforcing member is capable of bending and deforming each of the main reinforcing bars into a desired shape. The reinforcing steel supports placed at certain intervals are deformed into the shape of the rock wall surface and brought into contact with the rock wall surface to stabilize the rock wall surface, and then concrete is sprayed onto the rock wall surface. A method for constructing a rock wall using reinforced steel supports that support the rock. 3. A method for constructing a rock wall surface using a reinforcing steel support according to claim 2, characterized in that locking bolts are used in combination to stabilize the rock wall surface. 4. The reinforcing bar support according to claim 2, characterized in that a steel pipe inserted between predetermined reinforcing bars of the reinforcing bar support and cast along the outer periphery of the excavation cross section is used to stabilize the rock wall surface. A method of constructing a rock wall using a method of construction. 5. Claim 2, characterized in that lock bolts and steel pipes inserted between predetermined main reinforcing bars of the reinforcing steel support are used together to stabilize the rock wall surface.
A method for constructing a rock wall using reinforced steel supports as described in Section 1. 6 Three or more main reinforcing bars that extend parallel to each other in the length direction and are placed in related positions such as at each corner of a polygonal cross section, and both ends of these main reinforcing bars are connected and fixed to each other. It consists of a pair of fixing members and a reinforcing member that connects each of the main reinforcing bars to each other, and the reinforcing member is configured to be fixed to each of the main reinforcing bars by welding to connect each of the main reinforcing bars to each other, and The welding position of the reinforcing member to at least one of the main reinforcing bars is such that the reinforcing member is inscribed inside the main reinforcing bar in a space surrounded by each main reinforcing bar, and further, the reinforcing member is welded to at least one of the main reinforcing bars as desired. The reinforcing bar supports, which are arranged at intervals that can be bent into the shape of Spray concrete after covering the main reinforcing bars on the inner side of the
Next, the covering is removed and distribution bars are attached to the exposed main reinforcing bars, and then concrete is further poured to support the ground using a reinforcing bar support. 7. The rock wall surface using the reinforcing bar support according to claim 6, characterized in that lock bolts and steel pipes inserted between predetermined main reinforcing bars of the reinforcing bar support are used together to stabilize the ground wall surface. Construction method.