JPH07166539A - Construction method for steel framed reinforced concrete continuous underground wall - Google Patents

Abstract

PURPOSE:To firmly connect reinforcing bars of upper and lower units together at high quality and connect upper and lower steel members together safely, efficiently, and precisely in the construction method for a steel framed reinforced concrete continuous underground wall mainly performed for building a large- scale, large-depth underground structure. CONSTITUTION:Part of vertical reinforcements and horizontal reinforcements are not arranged in a lower unit 2, thus working opening sections 5 are provided between steel members 22, 22. Part of vertical reinforcements and horizontal reinforcements of the lower section are not arranged in an upper unit 4, thus the working opening sections 5 are secured. After a temporary frame 6 is installed, the lower unit 2 is suspended in an excavation groove 10. Stirrups 8 are mounted on the temporary frame 6, the lower unit 2 is temporarily fixed in the excavation groove 10, and the upper unit 4 is suspended above it. Steels of the upper and lower units 2, 4 are connected, and the working opening sections 5 are utilized to connect the steel members 22, 42.

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 continuous steel-framed reinforced concrete (hereinafter abbreviated as SRC) underground wall, which is mainly used for building large-scale and deep underground structures.

[0002]

2. Description of the Related Art A conventional continuous underground wall is a reinforced concrete structure (hereinafter abbreviated as RC) having reinforcing bars as reinforcing members, and upper and lower reinforcing cages having partition plates at both ends are joined together.
Reinforcing bars are lap joints, and partition plates are welded or high tension bolt joints. When the lower cage is temporarily placed in the excavation groove at the time of joining the reinforcing bar cage, a so-called kanzashi is set on the excavation groove and placed on the so-called kanzashi.

On the other hand, an SRC continuous underground wall in which a steel frame member is added to a reinforcing body so as to withstand deep underground soil pressure and groundwater pressure has been developed in recent years. Applicant is Japanese Patent Application No. 4-34722
I applied first for the construction method of SRC continuous underground wall related to No. 5. In the specification 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 S of the steel member d is exposed. A method is described in which, after joining the upper and lower steel frame members d, d, a large mesh streak e is applied to the exposed joint portion S and all the upper and lower rebars are joined together.

[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 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 around 1.5 m,
On the other hand, it is necessary to join the upper and lower steel frame members located in the steel-frame reinforcing-bar cage unit to each other, which causes work inside the steel-frame reinforcing-bar cage unit. In addition, since it is necessary to accurately join a plurality of heavy steel frame members to each other, the lower cage must be accurately fixed to the upper cage while being horizontally maintained. However, with the conventional temporary fixing method using a general hairpin, once installed, it is extremely impossible to adjust the height and maintain the level, which is a problem.

In this respect, the construction method of Japanese Patent Application No. 4-347225 satisfies the workability required for joining the steel frame members and the reinforcing bars, but the dimensional specifications of the steel reinforcing bar cage unit are small,
It can be implemented only within the reach of workers. That is, when the unit is large and it is necessary to enter the inside to join the steel frame members to each other, it is impossible. Further, in this method, since the joining positions of the upper and lower reinforcing bars are at the same level, there is room for improvement in terms of joining strength.

Therefore, it is an object of the present invention that, in the SRC continuous underground wall, the reinforcing bars of the upper and lower steel rebar cage units can be bonded by increasing the bonding strength, and the upper and lower steel members within the steel rebar cage unit are connected to each other. 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, and has improved safety, workability, and quality.

[0007]

As a means for solving the above-mentioned problems of the prior art, a method for constructing a continuous underground wall of a steel-reinforced concrete structure according to the present invention is a steel-framed reinforcing bar cage in which a steel frame member and a reinforcing bar are integrated. The lower unit 2 of the unit 1 is provided with at least one working opening 5 between the steel frame members 22 and 22 by not arranging a part of the vertical and horizontal bars thereof, and directly below the working opening 5. The horizontal connecting member 3 in which the steel frame members 22 are horizontally connected is attached to the position, and the upper unit 4 does not arrange a part of the vertical stripes and the horizontal stripes in the lower part thereof, so that the working opening 5 of the lower unit 2 is formed. The installation of the temporary units 6 of the lower unit 2 on both sides along the ground opening of the excavation groove 10 and then the lower unit 2 is suspended in the excavation groove 10, Or .. are inserted under the horizontal tie 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, the reinforcing bars of the lower unit 2 and the upper unit 4 are joined to each other, and the upper and lower steel frame members 22 of the steel frame rebar cage unit 1 are utilized by using the working opening 5. After joining the steel frame members 42 to each other and closing the working opening 5 with a reinforcing bar, the hairpin 8 is removed to proceed with the laying of the steel-framed rebar cage unit 1, and similarly, a necessary number of the lower unit 2 and the upper unit 4 are joined. The method is characterized in that the work is repeated to construct a steel rebar cage having a desired length, and then concrete is cast to integrate the steel member and the rebar with the concrete.

The temporary mounting base 6 may be constructed by constructing a jack 7 whose legs are adjustable in height, and operating the jack 7 to horizontally support the lower unit 2. . Further, when joining the steel members 22 of the lower unit 2 and the steel members 42 of the upper unit 4 to each other, the work scaffolding 9 is utilized by using the work opening 5 of the steel rebar cage unit 1 for the steel rebar cage unit 1. It is also characterized in that the steel frame members 22 and 42 are carried into the inside of the car and placed on the hairpin 8 and used as a scaffold for joining the steel frame members 22 and 42.

[0009]

The lower unit 2 is provided with at least one working opening 5 between the steel members 22, 22 by not arranging some of the vertical and horizontal bars 20, 21, ..., On the other hand, the upper unit 4 has its vertical and horizontal bars. Since the working openings 5 of the lower unit 2 are secured by not partially arranging the muscles 40, 41, ... (FIG. 1), the temporary placement is carried out on the temporary placement stand 6 via the hairpin 8. By suspending the upper unit 4 on the lower unit 2 (FIG. 2), the work openings 5 ... With a required size are reliably formed (FIG. 3). At this time, by operating the jack 7 (FIG. 4) of the temporary placement stand 6, the height of the temporary placement stand 6 can be adjusted,
Allows horizontal support of the lower unit 2.

Further, the work scaffolding 9 is carried into the inside of the steel rebar cage unit 1 using the work opening 5 and placed on the hairpin 8 to form a scaffold (FIG. 5). Therefore, after joining the upper and lower rebars, when joining the upper and lower steel frame members, the worker can easily enter and leave the inside of the steel rebar cage unit 1 by using the working opening 5. Therefore, the work of joining the upper and lower steel frame members 22 and 42 can be performed safely and quickly using the work scaffolding 9 as a scaffold. Moreover, since the lower unit 2 is maintained horizontally, the steel members 22 and 42 are accurately and reliably joined at the position of the joint portion P (FIG. 3). After that, a small reinforcing bar sufficient to close the working opening 5 is used.
Steel frame rebar cage unit 1 is installed just by attaching to
By repeating the same joining work of the upper and lower units as necessary, the SRC continuous underground wall can be constructed efficiently and safely.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows essential parts of a lower unit 2 and an upper unit 4 which constitute a steel frame rebar cage unit 1 formed by integrating a steel frame member and a reinforcing bar. The lower unit 2 is configured such that at least one working opening 5 is provided between the steel frame members 22 and 22 by not arranging a part of the upper vertical bar and the horizontal bar. That is, between four (although the number is not limited to this and is a necessary number as appropriate) steel frames 22 which are arranged substantially evenly between adjacent steel frames 22 (the distance between the webs is about 120 cm). ), One working opening 5 is provided at the upper position. The size is about 70 cm in height and 50 cm in width, which is the minimum size necessary for one worker to pass through. Therefore,
Vertical and horizontal rebars 20, so that the working opening 5 can be formed,
21 is arranged. The horizontal streaks 21 are arranged up to a position directly below the working opening 5, and the vertical streaks 20 are arranged so as not to close the working opening 5, and the vertical streaks 20 are arranged to be different in length from the adjacent vertical streaks 20. The working openings 5 are secured (however, the positions and the number of the working openings 5 are not limited to this, and the working openings 5 are carried out at desired places and numbers according to the construction conditions). A horizontal connecting member 3 made of grooved steel or the like, in which the steel frame members 22 are laterally connected, is attached to a position directly below the working opening 5.

On the other hand, the upper unit 4 has its steel member 4
2 is arranged at a position facing the steel frame member 22 of the lower unit 2, and at a position projecting further below the lower end of the steel frame member 42, joining of upper and lower units by not arranging a part of the vertical and horizontal lines. At some time, the working opening 5 of the lower unit 2 can be secured. Specifically, the vertical stripes 20 formed on the lower unit 2 in different lengths ...
To have the required length of wrap (Fig. 3).
The vertical stripes 40 ... Are arranged in different lengths.

FIG. 2 shows the lower unit 2 constructed as described above.
The figure shows a state in which the is inserted into the excavation groove 10 and temporarily placed. To this end, first, the cradle 6 for temporary placement of the lower unit 2 is installed on both sides along the aboveground opening of the excavation trench 10 (see FIG. 4A). The temporary placement pedestal 6 has sufficient strength to support the lower unit 2, and is made of H-shaped steel longer than the width of the steel rebar cage unit 1. The legs on both ends are jacks 7 whose height can be adjusted.
(FIG. 4B), and by operating the jack 7, it is possible to adjust and support the height and level of supporting the lower unit 2. In addition, a bolt 6a for locking a hairpin 8 described later is attached to the upper end surface of the temporary placement mount 6 in a vertically upward direction. The temporary mount 6
After installing the lower unit 2, the lower unit 2 is suspended in the excavation groove 10 by a crane, and a plurality of H-shaped steel hairpins 8 (about 250 cm in length) are inserted under the horizontal connecting member 3 of the lower unit 2 (Fig. 3), and the lower units 2 are temporarily fixed in the excavation groove 10 by placing them on the temporary placing frame 6 at appropriate intervals (see FIG. 4A). At this time, the hairpin 8 is fixed to the bolt 6a of the temporary mounting base 6 by fastening a through nut to the lower unit 2 so that the lower unit 2 is cut into the excavation groove 10a.
It is securely supported horizontally on the hairpin 8 ...

Thereafter, the work scaffolding 9 shown in FIG. 5 is placed on the hairpins 8 in the lower unit 2. The work scaffolding member 9 is composed of mesh streaks formed in a size (width about 100 cm, depth about 55 cm) that fills the space partitioned by the adjacent steel frame members 22 of the lower unit 2 substantially horizontally (Fig. 5A). reference). Further, the work scaffolding member 9 is configured to be foldable at the two hinges 9c and 9c so that it can be easily carried in and out of the lower unit 2 through the work opening 5. . In addition, the outer frame 9a of the work scaffolding 9 has a hairpin 8
A long hole-shaped bolt hole 9b is provided at a contact position (a portion surrounded by a circle in FIG. 5B) with (see FIG. 5C), and the bolt 8a of the hairpin 8 is passed through the bolt hole 9b (see FIG. 5).
D), the nut 12 can be tightened to be temporarily fixed. Therefore, the worker can freely enter and leave the inside of the steel-framed rebar cage unit 1 by using the work scaffolding 9 and the work opening 5, and secure the safe scaffolding to perform the steel-frame joining work of the unit.

FIG. 3 shows the connection between the lower unit 2 and the upper unit 4. That is, the steel frame member 42 of the upper unit 4 suspended by the crane is placed so as to abut on the steel frame member 22 of the lower unit 2. The mounting position is indicated by a symbol P in the drawing. In this state, the working opening 5 is secured. Therefore, first, the reinforcing bars of the lower unit 2 and the upper unit 4 are lap joint welded, gas pressure welded,
Join 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 reinforcing bars is increased.

Subsequently, the steel frame members 22 and 42 are joined together. A worker enters the steel rebar cage unit 1 using the work opening 5 to perform a joining work. At this time, since the work scaffolding 9 in the lower unit 2 can be effectively used as a scaffold, the work of joining the steel frame members can be safely and quickly advanced. The steel frame members are joined together by welding or high tension bolt joining. After the work of joining the steel members is completed, the work scaffolding 9 is detached and carried out from the work opening 5, and the work opening 5 is made slightly longer than the opening 5 with a mesh line or the like (not shown). The construction of the steel rebar cage unit 1 is completed by closing. After that, the hairpin 8 is removed, and the steel frame rebar 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 work of the lower unit 2 and the upper unit 4 is repeated to construct a steel rebar cage having a desired length. Then, finally, concrete is poured to integrate the steel frame member and the reinforcing bar with the concrete to complete the SRC continuous underground wall.

[0018]

EFFECTS OF THE INVENTION According to the method for constructing an SRC continuous underground wall of the present invention, the reinforcing bars of the upper and lower steel rebar cage units can be firmly joined together with high quality, and of course, the upper and lower steel frames in the steel rebar cage unit can be connected. Since members can be joined safely, efficiently, and precisely, safety and workability are improved, which contributes to the construction of a high-quality SRC continuous underground wall.

[Brief description of drawings]

FIG. 1 is a front view showing respective configurations 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.

4A and 4B are a side view and an enlarged view of a temporary placement stand.

5A, 5B, 5C, and 5D are a use state diagram, a general view, an enlarged plan view, and an enlarged side view showing a work scaffolding material.

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

[Explanation of symbols]

 1 Steel Reinforcing Bar Basket Unit 2 Lower Unit 20 Vertical Bar 21 Horizontal Bar 22 Steel Frame Member 3 Horizontal Connecting Material 4 Upper Unit 40 Vertical Bar 41 Horizontal Bar 42 Steel Frame Member 5 Working Opening 6 Temporary Stand 7 Jack 8 Working Scaffolding 10 Excavation trench

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Moi 1-5 Otsuka, Inzai-cho, Inba-gun, Chiba Inside the Takenaka Corporation Technical Research Institute (72) Inventor Kunihiko Horie 8-21-1 Ginza, Chuo-ku, Tokyo No. Stock Company Takenaka Corporation Tokyo Main Store

Claims (3)

[Claims] 1. A steel rebar cage unit formed by integrating a steel member and a reinforcing bar, wherein at least one work is performed between the steel members by not arranging a part of a vertical bar and a horizontal bar in an upper part of the lower unit. A horizontal connecting member that horizontally connects steel members is installed directly below the work opening, and the upper unit does not reinforce part of the vertical streaks and horizontal streaks at the bottom of the work opening. The work opening of the lower unit is ensured, and the temporary mounting cradle 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. , A plurality of hairpins are inserted under the horizontal tie member of the lower unit and placed on the temporary mounting base to temporarily fix the lower unit in the excavation trench, and then the upper unit is placed in the lower unit. of The upper and lower units are joined together, and the work openings are used to join the upper and lower steel members of the steel rebar cage unit, and the work openings are closed with reinforcement. After that, remove the hairpin and proceed with the laying of the steel rebar cage unit.In the same way, repeat the work of joining the required number of lower units and upper units to construct a steel rebar cage of the desired length, and then place concrete. A method of constructing a steel-framed reinforced concrete continuous underground wall, characterized by integrating steel members and steel bars with concrete. 2. The legs of the temporary placement pedestal are constituted by jacks whose height can be adjusted, and the lower unit is horizontally supported by operating the jacks to construct the lower unit.
The method for constructing a steel reinforced concrete continuous underground wall according to claim 1. 3. When joining the steel members of the lower unit and the upper unit, the work scaffold is carried into the inside of the steel rebar cage unit by using the working opening of the steel rebar cage unit and placed on the hairpin. The method for constructing a continuous steel-framed reinforced concrete underground wall according to claim 1, characterized in that the steel frame members are placed and the steel frame members are joined using the work scaffolding material.