JPH03212508A - Continuous underground wall construction method and reinforcement cage for continuous underground wall - Google Patents

Abstract

PURPOSE:To improve reliability dynamically by connecting a variable form reinforcement cage to a fixed form reinforcement cage built in a preceding vertical groove through couplings to be built in the following groove, and applying tension across both couplings by placing concrete. CONSTITUTION:After a fixed form reinforcement cage 1 having coupling member 10b is built in a precedingly dug vertical groove 21, concrete 22 is placed in the vertical groove 21. Subsequently, a following vertical groove 23 is dug, and a variable form reenforcement cage 13 having a coupling nember 10c is connected to the fixed form reinforcement cage 1 by fitting of the couplings 10b, 10c to be built in the vertical groove 13. Subsequently, concrete 25 is precedingly placed in a column-like cavity 24 formed in the coupling members 10b, 10c 10 apply tension between both fitted couplings. Further, concrete is placed in the following vertical groove 23.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for constructing a continuous underground wall that serves as a base when constructing foundations of structures, quays, etc. in the civil engineering and architectural fields, and a reinforcing bar cage for continuous underground walls. Regarding.

(Prior Art) As is well known, in the fields of civil engineering and architecture, various types of continuous concrete underground walls are often constructed as a base when constructing the foundations of structures.

Therefore, it is desirable to have a concrete continuous underground wall that has the desired bearing capacity and is more economical, and for this reason, a number of construction methods have been devised. Many rebar cages have been devised to make loading and transporting easier.

Conventional reinforcing bar cages are made by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars to create a rectangular cage-shaped frame, and using engagement plates or engagement rods that are made to protrude from both sides of the cage-shaped frame in advance. The leading reinforcing bar cage and the trailing reinforcing bar cage are engaged by wrapping them around each other, and because the reinforcement ratio at the engaging part is relatively small, it is difficult to prevent the reinforcing bars from being exposed to large bending forces after concrete is placed. There is a problem in that the engaging portion is prone to cracking.

Therefore, in order to ensure the engagement between the leading reinforcing bar cage and the trailing reinforcing bar cage and to reduce mechanical weaknesses, some of the reinforcing bars that make up the frame are constructed as joint reinforcing bars that are separate from the main building reinforcing bars. However, a method has been developed in which double-fitting joints are provided on both sides of the joint reinforcing bars, and the main body reinforcing bars and the joint reinforcing bars are loosely engaged with each other so that they can be displaced horizontally.

For example, Japanese Patent Application Laid-Open No. 82-244917 discloses a shaped reinforcing bar cage that has twin fitting joints and partition plates on both end sides of a cage-shaped frame, and three-dimensionally connects horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars. This method uses a cage-shaped frame formed by a cage-shaped frame and a variable-shaped reinforcing bar cage in which the cage-shaped frame and a double-fitting joint are connected by a loose engagement member, and increases the tolerance of joint fitting when closing reinforcing bars. An invention (hereinafter referred to as Invention A) has been disclosed that facilitates the work and increases the strength of reinforcing bars by increasing the reinforcement ratio of the engaging portion, thereby reducing construction costs.

In addition, JP-A-83-184 [i10] also includes the above-mentioned A
For the same purpose as the present invention, an invention (hereinafter referred to as B
invention) is shown.

(Problems to be Solved by the Invention) Invention A uses a variable-shaped reinforcing bar cage in which a cage-shaped frame and a double-fitting joint are connected by a loose engagement member, so that the engagement with the regular reinforcing bar cage is smooth; Furthermore, the variable rebar cage has a high dimensional tolerance and has the advantage of being able to flexibly accommodate construction errors, but it is somewhat difficult to align the fitting joints during erection work, and as mentioned above, Due to the high dimensional tolerance and clearance inherent in double-fitting joints, looseness occurs in the fit between double-fitting joints, and it is difficult to fill grout to eliminate the loosening. There is a problem in that the joint strength becomes weak and the joint does not become a rigid joint, leaving concerns about stress transmission.

Furthermore, invention B has the same problems as invention A, and also has the problem that processing and construction work is relatively expensive because the male and female pipes of the fitting joint need to be filled with mortar or grout.

The purpose of the present invention is to solve these problems and provide a method for economically constructing a continuous underground wall that is mechanically reliable and easy to erect leading and trailing reinforcing bar cages. In addition, the fitting process of the joint is smooth, there is no need to fill the joint with grout, and the structural strength is high, so there is no concern about stress transmission, and it is easy to manufacture for continuous underground walls. Our goal is to provide steel cages.

(Means for Solving the Problems) The gist of the present invention is the means shown below to achieve the above-mentioned objects. That is, (a) a continuous process in which a desired vertical trench is excavated in the ground, a reinforcing bar cage with joint members on both end sides is fitted with joints, and then concrete is poured into the said plentiful area. In an underground wall construction method, a structural frame is formed by three-dimensionally linking horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars; A shaped reinforcing bar cage equipped with a joint member (consisting of a groove or a section steel such as H or I) having a fitting joint and a partition plate is used as the preceding reinforcing bar cage and is then erected. A structural frame formed by three-dimensionally combining reinforcing bars and reinforcing bars, and a double fitting joint at both flange edges on both side edges of the structural frame (full, H, or 1 shaped steel) When closing the reinforcing bars by using a variable rebar cage formed by connecting joint members (consisting of the following) so as to be expandable and retractable in the horizontal direction via a loose engagement member as a trailing reinforcing bar cage, the reinforcing bar cage is formed by fitting the joint members. Continuous underground wall construction method in which concrete is placed in advance in a columnar cavity, tension is applied between twin fitting joints, and then concrete is poured abundantly; (b) Horizontal reinforcing bars, vertical reinforcing bars, and hoop reinforcing bars and a double-fitting joint and a partition plate at the end edges of both flanges fixed to the side edges of both ends of the form frame (from a groove or a section steel such as H or 1). (c) A structural frame formed by three-dimensionally connecting water-colored reinforcing bars, vertical reinforcing bars, and hoop reinforcing bars, and both ends of the structural frame. A continuous area in which a joint member (consisting of a groove or a section steel such as H or ■) having double-fitting joints at both flange end edges on the side edges is connected via a loose engagement member so as to be expandable and contractible in the horizontal direction. It is a variable-shaped reinforcing bar cage for inner walls, and (d) is characterized in that the twin fitting joints used in the fixed-shaped and variable-shaped reinforcing bar cages described in (a) to (C) above are composed of half-cut bodies of straight steel sheet piles. Make it one.

(Function) The method for constructing a continuous underground wall according to the present invention involves excavating a desired depth in the ground, and then attaching a reinforcing bar cage provided with joint members on the side edges of both ends. In the continuous underground wall construction method of fitting and erecting into the said bulge, and then pouring concrete into the bulge, first, after excavating the desired bulge, the shaped reinforcing bar cage is used as a preliminary reinforcing bar cage and is erected. A structural frame formed by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and a double-fitting joint and a partition plate fixed to the side edges of both ends of the structural frame, and attached to both flanges. Preferably, the joint member is constructed of a groove or H or summer steel section, so that the construction is strong and can be carried by a crane. There is little morphological deformation even when raising α, and since the partition plate is fixed to the edges of both flanges of the highly rigid joint member, deformation during construction is small and it can be installed accurately in the designated position of the plump area. can.

The process of constructing the pond wall is to excavate the above-mentioned abundance on both sides, leaving the ground for closing, and erect a preliminary reinforcing bar cage, then excavate so that the closing abundance is continuous with the aforementioned abundance, and then close to the closing abundance. However, in the present invention, the trailing reinforcing bar cage includes a structural frame formed by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and both ends of the structural frame. A variable type in which a groove having a double-fitting joint on both flange end edges or a joint member made of a section steel such as H or 1 is connected via a loose engagement member so that it can expand and contract in the horizontal direction. Since reinforcing bars are closed using reinforcing bar cages, even if the preceding reinforcing bar cage is deformed due to manufacturing errors or distortions during erection, or there is some deviation in the erection position, the joint members will remain in the form of the building frame. On the other hand, since they are connected so as to be expandable and contractible in the horizontal direction via the loose engagement member, the joint member of the deformable reinforcing bar cage moves appropriately with respect to the joint member of the preceding reinforcing bar cage, allowing complete joint fitting.

In addition, in the present invention, since a highly rigid section steel is used as the joint member as described above, there is little morphological deviation and centering of the joint is easy. Since it moves appropriately following the movement, smooth and efficient joint fitting work can be performed.

Next, in the present invention, concrete is pre-cast in the columnar cavity formed by fitting the joint members of the regular reinforcing bar cage, which is the leading reinforcing bar cage, and the variable-shaped reinforcing bar, which is the trailing reinforcing bar cage. However, both joint members are forced apart by this pre-cast concrete, and as a result, a large tension is applied between the twin fitting joints.

Therefore, there is no gap between the double-fitting joints, and the double-fitting joints can function as rigid joints and can transmit large acting forces.

In other words, in the present invention, concrete is poured after forming reinforcing bars with no mechanical weaknesses as described above.
It is possible to economically construct continuous underground walls with high quality and reliability.

Next, the shaped reinforcing bars for continuous underground walls according to the present invention include a supplementary frame formed by three-dimensionally combining horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and fixed to the side edges of both ends of the supplementary frame. The edges of both flanges are equipped with a double-fitting joint and a groove with a partition plate, or a joint member made of H or ■ shaped steel, and the highly rigid joint member and complementary frame are fixed together. Therefore, it is easy to manufacture and has good dimensional stability.

In addition, since double-fitting joints are provided on both flange edges of the section steel, it is structurally strong and less likely to be damaged during handling.Furthermore, it is highly morphologically stable, making erection work easier. It's easy.

Next, the ability of variable reinforcing bars for continuous underground walls according to the present invention is as follows:
A complementary frame formed by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and grooves or H or 1 grooves having double-fitting joints at both flange end edges at both end side edges of the complementary frame. It has a structure in which joint members made of shaped steel such as
When fitting the joint to the shaped reinforcing bar, the joint member moves freely in the horizontal direction via the loose engagement member, making the fitting smooth and easy. As in the case of shaped steel bars, the structure is such that double fitting joints are provided at both flange edges of the shaped steel, making the structure extremely sturdy and preventing damage during fitting and erection work. Very few.

In addition, in the present invention, as described above, concrete is placed in advance in the columnar cavity formed by the fitting of the joint member between the regular reinforcing bar part, which is the leading reinforcing bar part, and the variable shape reinforcing bar part, which is the trailing reinforcing bar part. However, since the joint members for fixed-shaped reinforcing bars and variable-shaped reinforcing bars are configured with double-fitting joints at the edges of both flanges of the section steel, concrete should be poured immediately after the joints are fitted. Even if the concrete leaks, there is no fear of concrete leakage, and the poured concrete can be pushed and expanded to form a columnar cavity that exerts an acting force on the loose engagement member.

Furthermore, by using semi-cut pieces of straight steel sheet piles as double-fitting joints for both fixed and variable reinforcing bars, we are able to take advantage of its cosine joint properties to create extremely reliable joints in terms of strength and water-tightness. result.

(Example) FIG. 1 is a schematic plan view of a shaped reinforcing bar R1 according to the present invention.
The horizontal reinforcing bars 2, the vertical reinforcing bars 3, and the band reinforcing bars 4 are three-dimensionally connected to form a rectangular complementary frame 5, and then both end side edges 5a of the complementary frame 5 are formed.

5b, a double fitting joint 7a is provided at both flange end edges 6a to 6d.
~7d and H-shaped steels 9a and 9b having partition plates 8a to 8d
Although the above-mentioned prosthetic frame 5 is already a widely known structure, a detailed explanation will be omitted.

Now, the joint members 10a and lOb are straight steel sheet piles (
JIS-^-5528) One side joints of 12a to 12d are fused and welded together with long steel strips 11a and 11b as web materials to form build-up H-beams 9a and 9b, and the partition plate 8a is 8d are melted so as to protrude perpendicularly to the double fitting joints 7a to 7d, as is clear from the figure.

The partition plates 8a to 8d have the function of stabilizing the erection posture of the shaped reinforcing bars 1 by coming into contact with the voluptuous surface (not shown), and the function of preventing poured concrete from going around, but this is also a widely known structure. Therefore, detailed explanation will be omitted.

In the present invention, the regular reinforcing bar capacity 1 is used as the leading reinforcing bar capacity, and the variable reinforcing bar RI3, which will be explained next in FIG. 2, is used as the trailing reinforcing bar capacity for closing.

FIG. 2 is a schematic plan view of the deformable reinforcing bar R13, and the same reference numerals as those in FIG. 1 are the same members, so redundant explanation will not be given.

In FIG. 2, the joint members 10c and lOd have the same structure as the joint members 10a and lOb, but both ends of the joints 10a to 14d are fixed to the flanges 14a to 14d on the opposite side of the double fitting joints 7a to 7d. 15a.

A plurality of portal reinforcing bars represented by 15b are installed vertically, and each of the portal reinforcing bars 15a and 15b is a rectangular parallelepiped reinforcing bar formed by three-dimensionally combining water burial reinforcing bars 2, vertical reinforcing bars 3, and band reinforcing bars 4. The horizontal reinforcing bars 2 and spiral reinforcing bars 1 of the cage-shaped frame IB
They are loosely engaged with each other through pins 7a to 17d so that they can move in the direction of water 5V.

Therefore, during actual construction, the cage-shaped frame 16 is installed so as not to move relative to the plump bottom, so the joint members 10c and IOd move horizontally relative to each other, allowing smooth joint fitting. .

That is, as mentioned above, the movement of the joint members 10c and 10d is possible because of the loose engagement between the portal reinforcing bars 15a and 15b and the horizontal reinforcing bars 2 and the spiral reinforcing bars 17a to 17d. , these are collectively referred to as "C". In the present invention, the joint members are connected horizontally via loose engagement members so as to be expandable and contractible in the horizontal direction, and the joint member 10e
, lOd, the dimensions of the reinforcing bar cage can be changed mainly in the horizontal direction, and therefore, in the present invention, such a reinforcing bar cage is referred to as a variable-forming reinforcing bar cage 13.

Thus, the loose engagement member is not limited to this form, and a loose engagement configuration as shown in the schematic perspective view of FIG. 3 can be adopted.

Although each member is omitted in FIG. 3 for convenience of explanation, in the joint member 10c, horizontal reinforcing bars 2, vertical reinforcing bars 3, and a band reinforcing bar The ends 5c of a rectangular cage-shaped frame 5 formed by three-dimensionally bonding 4 and 4 are inserted in a loosely engaged manner so as to be slidable in the horizontal direction. Although not shown, use appropriate guide hardware.

Various slide mechanisms are already well known, and one may be selected and adopted depending on the purpose.

Next, joint members 10e and 1O[' used in continuous underground wall construction methods according to different embodiments of the present invention will be explained according to the schematic partial views shown in FIGS. 4 and 5.

The joint member lop shown in FIG. 4 has double fitting joints 7e welded to both flanges of a channel steel 18. A portal reinforcing bar 15c is fixed to the channel steel 18, and a spiral reinforcing bar 17e is used to slowly engage the joint member lop. It is composed of

The joint member lO in FIG. However, the horizontal reinforcing bar 2 is held loosely by the clamp fitting 2.
This is an example of a loose engagement configuration at 0.

Now, as mentioned above, shaped reinforcing bar iVl! 1 and deformable reinforcing bar 813
The main points of the continuous underground wall construction method according to the present invention using
The schematic partial plan view of FIG. 6 will be explained.

Figure 6 shows that fixed reinforcing bars ml are erected in the previously excavated Pampan 21, concrete 22 is poured, then the trailing Pampan 23 is excavated, and variable-shaped reinforcing bars a13 are fitted with the fixed reinforcing bars R1 while being constructed. After the fitting, concrete 25 is placed in advance in the columnar cavity 24 formed between the joint members 10b and lOc, and tension is applied between the two fitting joints.

Arrows 26a and 26b indicate the pushing and spreading force acting between the joint members 10b and 10c due to the internal pressure of the concrete 25.

Next, with reference to FIGS. 7a-H, a schematic procedure of the continuous underground wall construction method according to the present invention will be explained.

Figure 7a shows the desired size of the voluptuous areas 27a and 2 in the ground for underground wall construction.
FIG. 7 shows the state in which 7b has been excavated, and the preceding reinforcing bars R2 made of shaped reinforcing bar cages are attached to each of the above-mentioned plumes 27a and 27b.
8a and 28b have been erected, but the preceding reinforcing bar R2
A canvas sheet is often placed on the side surfaces of 8a and 28b facing the groove side in order to prevent the collapse of the groove surface of the above-mentioned plumes 27a and 27b and to make concrete placement easier. , illustration and description are omitted for convenience of explanation.

FIG. 7C and FIG. 7D show the preceding reinforcing bar cage 2, respectively.
After finishing the erection of 8a and 28b, concrete 2
9a and 29b, and then the plump 27a.

It shows the situation where the plump 27c which communicates with 27b is excavated.

FIG. 7e shows trailing reinforcing bars made of variable-shaped reinforcing bar cages in the vertical groove 27c? Il! 30 is erected while being fitted with the preceding reinforcing bars R28a and 28b, and FIG.
As explained in the figure, concrete 32a, 32b is pre-cast in columnar cavities 31a, 31b formed by fitting the joints together.

Now, as mentioned above, by pouring concrete into the columnar cavities 31a and 31b, the preceding reinforcing bar cage 28a,
Since a pushing and expanding force acts between the joint members of the reinforcing bar cage 28b and the trailing reinforcing bar cage 30, a strong tension is applied between the double fitting joints, and as a result, the leading and trailing reinforcing bar cages are strongly engaged and the structural weakness is eliminated. There's nothing left.

FIG. 7g shows a state in which concrete is poured into the ample area 27c as the final step and construction is completed.

Next, the double-fitting joint according to the present invention will be explained.

Conventionally, various types of joints have been used for reinforcing bar cages, such as male and female pipes, combinations of pipes and round bars, or combinations of pipes and shaped steel.
Both have large clearances, tend to be structural weaknesses, and have the disadvantage of high processing costs.

Therefore, the half-section joint for straight steel sheet piles according to the embodiment of the present invention is a cosine joint, has a small clearance, has extremely high water-stopping properties, is easy to manufacture, and is inexpensive.

As such joints, male and female joints for straight steel sheet piles, U-shaped, and Z-shaped steel sheet piles specified in J15-A-5528 are preferably the same, and joints for straight steel sheet piles are particularly suitable for processing, strength, and It is in this sense that the double-fitting joint according to the invention is used, as it is the most suitable for the purpose in terms of price.

(Effects of the invention) The continuous underground wall construction method according to the present invention has a strong structure;
In addition, it uses fixed-shaped reinforcing bar cages and variable-shaped reinforcing bar cages that have good joint fitability, making it easy to construct and work efficiently, making it extremely economical. This makes it possible to construct continuous underground walls with excellent strength and reliability.

Further, the fixed reinforcing bar cage and variable shape reinforcing bar cage according to the present invention are economical because their joint members have high strength and morphological stability, and are easy to manufacture.

Furthermore, by the combination of the fixed-shaped reinforcing bar cage and the variable-shaped reinforcing bar cage according to the present invention, the columnar cavity formed between the joint members has high morphological rigidity and is easy to place concrete. Effective tension is applied to the joint by internal pressure, making it possible to obtain a reinforcing bar cage with no weak points.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of a shaped reinforcing bar dragon according to the present invention, FIG. 2 is a schematic plan view of a deformable reinforcing bar cage, FIG. 3 is a partial schematic perspective view showing a loose engagement configuration of a joint member, and FIG. Fig. 5 is a partial schematic plan view showing the structure of a joint member according to a different embodiment, and Fig. 6 is a partial plan view showing the structure of a joint member according to a different embodiment. Figures 7g to 7g are explanatory diagrams schematically showing the steps of the continuous underground wall horizontal construction method according to the present invention. 1... Shaped reinforcing bar cage 2... Water/Reinforcing bar material 3
... Vertical reinforcement material 4 ... Hoop reinforcing bar 5 ... Complementary frame 5a, 5b ... End side edges 6a to 6d ... Flange end edges 7a to 7c ... Double fitting joint 8a ~8d...Partition plate 9a. 10a-10"...Joint members 11a, llb...Long steel strip plates 12a-12d...Straight steel sheet pile 3...Variable reinforcing bar cages 4a-14d...Flanges 5a, 15d... Portal reinforcing bar 1B... Complementary frame 7
a-17r... Spiral reinforcing bar 8... Channel steel 19...■ Shape steel 20.
・・Clamp fitting 2 ・・Vertical 22 ・・Concrete 23 ・・ Trailing vertical groove 24 ・・Columnar cavity 25 ・・Concrete 26a, 26
b -... Pushing and spreading force 27a, 27b,... Vertical 28a, 28b... Leading reinforcing bar cage 29a, 29b... Concrete 30... Trailing reinforcing bar cage 31a, 31b... Column-shaped cavity 9b...・H-shaped steel grooves 32a, 32b...Concrete 33...Concrete applicant Nippon Steel Corporation sub-agent

Claims (6)

[Claims] (1) After excavating a desired trench in the ground, a reinforcing cage with joint members on both end sides is fitted with joints and built into the trench, and then concrete is poured into the trench. In the underground wall construction method, there is a cage-shaped frame formed by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and two flanges fixed to the side edges of both ends of the cage-shaped frame. A cage-shaped frame in which a regular reinforcing bar cage equipped with a fitting member having a fitting joint and a partition plate is used as a leading reinforcing bar cage and is erected, and then horizontal reinforcing bars, vertical reinforcing bars, and hoop reinforcing bars are three-dimensionally connected. and a variable-form reinforcing bar cage formed by connecting joint members having double-fitting joints at both flange end edges so as to be expandable and contractible in the horizontal direction via loose engagement members at the side edges of both ends of the cage-shaped frame. , When closing the reinforcing bars as a trailing reinforcing bar cage, concrete is placed in advance in the columnar cavity formed by the fitting of the joint members, tension is applied between the twin fitting joints, and then concrete is poured into the vertical groove. Continuous underground wall construction method. (2) A cage-shaped frame formed by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and a double-fitting joint and a partition at the end edges of both flanges fixed to the side edges of both ends of the cage-shaped frame. A shaped reinforcing bar cage for continuous underground walls equipped with a joint member having plates. (3) A cage-shaped frame formed by three-dimensionally connecting horizontal reinforcing bars, vertical reinforcing bars, and band reinforcing bars, and a double-fitting joint and a partition plate on both flange edges at both end side edges of the cage-shaped frame. A variable rebar cage for continuous underground walls, which is formed by connecting joint members via loose engagement members so that they can expand and contract in the horizontal direction. (4) The method for constructing a continuous underground wall according to claim 1, characterized in that regular and variable-shaped reinforcing bar cages having half-cut bodies of straight steel sheet piles are used as the double-fitting joints. (5) The shaped reinforcing bar cage for continuous underground walls according to claim 2, wherein the double fitting joint is constructed of a half-cut straight steel sheet pile. (6) The variable reinforcing bar cage for continuous underground walls according to claim 3, wherein the double fitting joint is constructed of a half-cut straight steel sheet pile.