JP3062910B2 - Construction method of steel basement reinforced concrete continuous basement wall - 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 continuous underground wall of a steel reinforced concrete structure (hereinafter abbreviated as "SRC") mainly used for construction of a large-scale and deep-depth underground structure.

[0002]

2. Description of the Related Art A conventional general continuous underground wall is made of reinforced concrete (hereinafter abbreviated as RC) using reinforcing bars as reinforcements, and upper and lower rebar cages provided with partition plates at both ends are joined together.
The reinforcing bars are lap joints, and the partition plates are welded or joined by high tension bolts. In addition, when the lower cage is temporarily placed in the excavation groove when joining the reinforcing steel cage, a so-called hairpin is installed on the excavation groove and is placed on the excavation groove.

On the other hand, an SRC continuous underground wall in which a steel member is added to a reinforcing member so as to withstand the earth pressure and the underground water pressure of a deep underground has been developed in recent years. The applicant is Japanese Patent Application No. Hei 4-34722.
We applied for construction method of SRC continuous underground wall concerning No. 5 earlier. In the description and the drawings, as shown in FIG. 6, the upper and lower steel rebar cage units a are arranged with vertical bars b and horizontal bars c so that the joint portions S of the steel members d are exposed. A method is described in which, after joining the upper and lower steel members d, d, a large mesh bar e is applied to the exposed joint portion S, and all the upper and lower bars are joined.

[0004]

In the case of the conventional RC continuous underground wall, the joining of the upper and lower reinforcing bars or the partition plates is relatively easy. However, in the case of RC, the wall pressure reaches 3 m to 5 m at a large depth, the construction cost increases, and the utilization of the underground space is limited. On the other hand, in the case of the SRC continuous underground wall, the wall pressure can be reduced to about 1.5 m,
On the other hand, it is necessary to join upper and lower steel frame members located inside the steel frame cage unit, and work inside the steel frame cage unit occurs. Moreover, since it is necessary to accurately join a plurality of heavy steel members to each other, the lower basket must be temporarily fixed to the upper basket accurately and horizontally. However, in the conventional temporary fixing method using a general hairpin, once installed, it is almost impossible to adjust the height of the temporary fixing method and maintain the horizontal position.

In this respect, the construction method disclosed in Japanese Patent Application No. 4-347225 satisfies the workability required for joining a steel frame member and a reinforcing bar, but the dimensions of the steel frame rebar cage unit are small.
Implementation is only possible within the reach of workers. That is, when the unit is large and it is necessary to enter the inside of the unit and join the steel members, it is not possible to perform the operation. In addition, since the joining method of the upper and lower reinforcing bars is at the same level, there is room for a slight improvement in the joining strength.

[0006] Accordingly, an object of the present invention is to provide an SRC continuous basement wall in which the reinforcing bars of the upper and lower steel frame cage units can be joined with increased joint strength, and the upper and lower steel frame members in the steel frame steel cage unit are connected to the unit. It is an object of the present invention to provide a method for constructing an SRC continuous underground wall which can be efficiently joined as a safe work inside a building and improved in safety, workability and quality.

[0007]

As a means for solving the above-mentioned problems of the prior art, a method for constructing a steel-framed reinforced concrete continuous underground wall according to the present invention comprises a steel-frame cage formed by integrating a steel member and a reinforcing bar. The lower unit 2 of the unit 1 is provided with at least one working opening 5 between the steel members 22, 22 by not arranging a part of the vertical and horizontal streaks. The upper unit 4 does not arrange a part of the vertical streak and the horizontal streak at the lower part thereof, so that the work opening 5 of the lower unit 2 is not arranged. After the gantry 6 for temporary placement of the lower unit 2 is installed on both sides along the ground opening of the excavation groove 10, the lower unit 2 is suspended in the excavation groove 10. Or .. Are inserted under the horizontal connecting member 3 of the lower unit 2 and placed on the temporary mounting base 6 to temporarily fix the lower unit 2 in the excavation groove 10, and then the upper unit 4 is suspended on the lower unit 2, and the reinforcing members of the lower unit 2 and the upper unit 4 are joined together, and the upper and lower steel members 22 of the steel frame cage unit 1 are connected to each other by using the working opening 5. The steel members 42 are joined together, the working opening 5 is closed with a reinforcing bar, the hairpin 8 is removed, and the laying of the steel frame cage unit 1 is advanced. Similarly, the necessary number of the lower unit 2 and the upper unit 4 are joined. After the work is repeated to construct a steel rebar cage of a desired length, concrete is cast to integrate the steel member and the rebar with the concrete.

Incidentally, the temporary placing stand 6 is constituted by a jack 7 whose legs are adjustable in height, and the lower unit 2 is supported horizontally by operating the jack 7. . Further, when the steel frame members 22 of the lower unit 2 and the steel frame members 42 of the upper unit 4 are joined to each other, the work scaffolding material 9 is formed by using the work opening 5 of the steel frame cage unit 1 and the steel frame cage unit 1. It is also characterized in that it is carried into the inside of the car and placed on the hairpin 8, and this is used as a scaffold to join the steel members 22, 42.

[0009]

The lower unit 2 has at least one working opening 5 between the steel members 22, 22 by partially arranging the vertical and horizontal streaks 20, 21,. Since the working openings 5 of the lower unit 2 are secured by not arranging some of the streaks 40, 41... (FIG. 1), they are temporarily placed on the temporary placing stand 6 via the bridge 8. By suspending the upper unit 4 on the lower unit 2 (FIG. 2), working openings 5 of a required size are reliably formed (FIG. 3). At this time, the height of the temporary placing base 6 can be adjusted by operating the jack 7 (FIG. 4) of the temporary placing base 6;
The lower unit 2 can be supported horizontally.

The work scaffolding material 9 is carried into the steel reinforced cage unit 1 using the work opening 5, and is placed on the hairpin 8 to form a scaffold (FIG. 5). Therefore, after the joining operation of the upper and lower rebars is completed, when joining the upper and lower steel members, the worker can easily go in and out of the steel rebar cage unit 1 by using the working opening 5. Thus, the joint work of the upper and lower steel frame members 22 and 42 can be performed safely and quickly using the work scaffold 9 as a scaffold. Moreover, since the lower unit 2 is kept horizontal, the steel members 22, 42 are accurately and reliably joined at the position of the joint P (FIG. 3). Thereafter, a small reinforcing bar sufficient to close the working opening 5 is inserted into the opening 5.
The steel frame cage unit 1 is constructed simply by attaching it to the
By repeating the same joining operation of the upper and lower units as necessary, the SRC continuous underground wall is efficiently and safely constructed.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows essential parts of a lower unit 2 and an upper unit 4 constituting a steel frame cage unit 1 formed by integrating a steel frame member and a reinforcing bar. The lower unit 2 has a configuration in which at least one work opening 5 is provided between the steel members 22, 22 by not arranging a part of the upper and lower streaks. That is, the four (although the number is not limited to this, and the number is required as appropriate) four substantially equally arranged steel members 22 adjacent to each other (the distance between the webs is approximately 120 cm). The work openings 5 are provided one by one in the upper part of the parentheses. The size is 70 cm in height and 50 cm in width, which is the minimum size that one worker can pass through. Therefore,
The vertical and horizontal reinforcing bars 20 are formed so that the work opening 5 can be formed.
Arrange 21 bars. The horizontal streaks 21 are arranged to a position immediately below the work opening 5, and the vertical streaks 20 are arranged so as not to block the work opening 5, and are arranged at different lengths from the adjacent vertical streaks 20. The working openings 5 are secured (however, the position and the number of the working openings 5 are not limited to this, and the working openings 5 are implemented at desired places and numbers according to the construction conditions). At the position directly below the working opening 5, a horizontal connecting member 3 made of a channel steel or the like in which the steel members 22 are horizontally connected is attached.

On the other hand, the upper unit 4 has its steel member 4
2 is disposed at a position facing the steel member 22 of the lower unit 2, and at a position protruding further below the lower end of the steel member 42, some of the vertical and horizontal streaks are not arranged, thereby joining the upper and lower units. In some cases, the working opening 5 of the lower unit 2 can be secured. Specifically, the vertical streaks 20 formed at different lengths of the lower unit 2.
(See FIG. 3)
..) Are also arranged at different lengths.

FIG. 2 shows the lower unit 2 constructed as described above.
Is inserted into the excavation groove 10 and temporarily placed and installed. For that purpose, first, the gantry 6 for temporary placement of the lower unit 2 is installed on both sides along the ground opening of the excavation trench 10 (see FIG. 4A). The temporary mounting base 6 has sufficient strength to support the lower unit 2, and is made of an H-shaped steel longer than the width of the steel frame cage unit 1. The feet at both ends are height-adjustable jacks 7
(FIG. 4B). By operating the jack 7, the lower unit 2 can be supported by adjusting its height and horizontality. A bolt 6a for locking a hairpin 8 described later is attached to the upper end surface of the temporary mounting base 6 vertically upward. The temporary mounting base 6
After installing the lower unit 2, the lower unit 2 is hung into the excavation groove 10 by a crane, and a plurality of hairpins 8 (about 250 cm in length) made of H-shaped steel are inserted below the horizontal connecting member 3 of the lower unit 2 (FIG. 3), and the lower unit 2 is temporarily fixed in the excavation groove 10 by being placed on the temporary mounting base 6 at appropriate intervals (see FIG. 4A). At this time, since the hairpin 8 is fixed by passing the nut 6 through the bolt 6a of the temporary placing base 6, the lower unit 2
It is securely supported horizontally on the hairpin 8 inside.

Thereafter, the work scaffold 9 shown in FIG. 5 is placed on the hairpins 8 in the lower unit 2. The work scaffolding material 9 is made of a mesh streak formed in a size (about 100 cm in width and about 55 cm in depth) to substantially horizontally fill the space partitioned by the adjacent steel members 22 of the lower unit 2 (FIG. 5A). reference). Further, the work scaffolding material 9 is configured to be foldable at two hinges 9c, 9c so that the work can be easily carried in and out of the lower unit 2 through the work opening 5. . Further, the outer frame 9a of the work scaffold 9 has a pin 8
5B is provided with an elongated bolt hole 9b (see FIG. 5C), and the bolt 8a of the hairpin 8 is passed through the bolt hole 9b (see FIG. 5B).
D), the nut 12 can be temporarily fixed by being tightened. Therefore, the worker can freely enter and leave the inside of the steel-frame reinforced cage unit 1 by using the work scaffolding material 9 and the work opening 5, and secure a safe scaffold and perform the steel frame joining work of the unit.

FIG. 3 shows a connection state between the lower unit 2 and the upper unit 4. That is, the steel member 42 of the upper unit 4 suspended by the crane is placed so as to abut on the steel member 22 of the lower unit 2. The mounting position is indicated by a symbol P in the figure. In this state, the working opening 5 is secured. Accordingly, first, the reinforcing bars of the lower unit 2 and the upper unit 4 are overlapped with each other, and joint welding, gas pressure welding,
It is joined by means such as crimping. At this time, the upper and lower vertical stripes 4
Since 0 and 20 are joined to each other at different level positions, the joining strength between the upper and lower rebars is increased.

Subsequently, the steel members 22, 42 are joined together. Using the work opening 5, a worker enters the steel reinforced cage unit 1 to perform a joining operation. At that time, the work scaffolding material 9 in the lower unit 2 can be effectively used as a scaffold, so that the joining operation of the steel frame members can be safely and quickly performed. The joining of the steel members is performed by welding or high tension bolt joining. After the joining work of the steel members is completed, the work scaffolding material 9 is removed and carried out from the work opening 5, and the work opening 5 is slightly longer than the opening 5 by a mesh bar or the like (not shown). By closing, the construction of the steel frame cage unit 1 is completed. Thereafter, the hairpin 8 is removed, and the steel reinforced cage unit 1 is sunk into the excavation groove 10 by a crane.

When a large number of units need to be connected, the above-described joining operation of the lower unit 2 and the upper unit 4 is repeated to construct a steel frame cage having a desired length. Finally, concrete is cast and the steel frame member and the reinforcing bar are integrated with the concrete to complete the SRC continuous underground wall.

[0018]

According to the method for constructing an SRC continuous underground wall of the present invention, the reinforcing bars of the upper and lower steel frame cage units can be firmly joined to each other with high quality, as well as the upper and lower steel frames in the steel frame cage unit. Since the members can be joined safely and efficiently and with high accuracy, safety and workability are improved and contribute to the construction of a high quality SRC continuous underground wall.

[Brief description of the drawings]

FIG. 1 is a front view showing the configuration of upper and lower units.

FIG. 2 is a plan view showing a temporary placement state of a lower unit.

FIG. 3 is a front view showing a joined state of upper and lower units.

FIGS. 4A and 4B are a side view and an enlarged view of a temporary mounting base.

FIGS. 5A, 5B, 5C, and 5D are a use state diagram, an overall view, an enlarged plan view, and an enlarged side view showing a work scaffold.

FIG. 6 is a front view of a conventional steel frame cage unit.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 steel frame cage unit 2 lower unit 20 vertical bar 21 horizontal bar 22 steel frame member 3 horizontal connecting member 4 upper unit 40 vertical bar 41 horizontal bar 42 steel frame member 5 work opening 6 temporary mounting base 7 jack 8 hairpin 9 work scaffolding material 10 Digging trench

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Moi 1-5, Otsuka, Inzai-cho, Inba-gun, Chiba Prefecture Inside the Technical Research Center, Takenaka Corporation (72) Kunihiko Horie 8--21 Ginza, Ginza, Chuo-ku, Tokyo No. 1 Takenaka Corporation Tokyo Main Store (56) References JP-A-2-147716 (JP, A) JP-A-6-193050 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) E02D 5/20

Claims (3)

(57) [Claims] 1. A steel rebar basket unit formed by integrating a steel frame member and a reinforcing bar, the lower unit does not arrange a part of a vertical bar and a horizontal bar above the lower unit, so that at least one work is performed between the steel frame members. The upper unit does not arrange a part of the vertical streak and the horizontal streak at the lower part of the work unit. The work opening of the lower unit is ensured, and the gantry for temporary placement of the lower unit is installed on both sides along the ground opening of the excavation trench, and then the lower unit is suspended in the excavation trench. Inserting a plurality of hairpins under the horizontal connecting member of the lower unit, placing the lower unit on the temporary mounting base and temporarily fixing the lower unit in the excavation trench, and then replacing the upper unit with the lower unit of In addition to joining the reinforcing bars of the lower unit and the upper unit with each other, joining the upper and lower steel members of the steel frame cage unit using the working opening, and closing the working opening with the reinforcing bar. After that, remove the hairpin and proceed with the laying of the steel frame cage unit.Similarly, repeat the joining work of the required number of lower unit and upper unit, construct the steel frame cage of the desired length, and then cast concrete. A method for constructing a steel-framed reinforced concrete continuous underground wall, comprising integrating a steel frame member and a reinforcing bar with concrete. 2. The leg of the temporary placing stand is constituted by a jack whose height can be adjusted, and the jack is operated to support the lower unit horizontally to be constructed.
The construction method of the steel-framed reinforced concrete continuous underground wall according to claim 1. 3. When joining the steel frame members of the lower unit and the upper unit, the work scaffold is carried into the steel frame cage unit using the work opening of the steel frame cage unit, and the work scaffold is placed on the hairpin. The method for constructing a steel-framed reinforced concrete continuous underground wall according to claim 1, wherein the work is carried out and the steel scaffold members are joined using the work scaffold.