JPH0377889B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a joint member in a diaphragm wall.

Generally, an underground continuous wall is constructed for each unit wall, so a joint is created between the preceding unit wall and the following unit wall. Conventionally, in order to obtain shear strength in the vertical and horizontal directions at this joint, a joint member in which joint reinforcing bars processed into various shapes are fixed to the side surface of a partition plate that partitions the ends of the preceding unit wall is used.

However, in conventional joint members, it is necessary to use a large amount of joint reinforcing bars in order to obtain the required shear strength, which requires a great deal of labor and time to secure the joint reinforcing bars (generally welding). Since the joint reinforcing bars are arranged in a complicated manner vertically and horizontally, it is difficult to completely clean the slime caused by muddy water adhering to the reinforcing bars, resulting in the disadvantage that the required strength cannot be obtained.

This invention solves the above-mentioned conventional problems, simplifies the shape of the joint member while maintaining the required shear strength, and thereby saves labor during assembly. The object is to provide a joint member that can be easily processed.

That is, in this invention, a plurality of joint plates having a large number of notch openings spaced apart on both sides and having an overall shape of a fern are arranged vertically at intervals, and a plurality of joint plates are arranged vertically at intervals. A partition plate is fixed vertically and at right angles, and elongated members for closing the entrances of each notch opening are fixed vertically to both end edges of the joint plate, and the opposing joint plates are connected together. A joint member characterized by being connected by a large number of steel bars.

The embodiments shown in the drawings will be described below.

As shown in FIG. 1, the joint member 1 includes a plurality of vertically oriented partition plates 2a, 22b, 2c, and a pair of joint plates 3a, 3b spaced apart from each other. Partition plates 2a and 2b are provided on the surface,
Furthermore, partition plates 2b and 2c are fixed to both sides of the joint plate 3b at right angles by welding or the like.
Three or more joint plates 3a, 3b may be arranged in the partition portion depending on the width of the wall.
Also, the partition plates 2a, 2b, 2c and the joint plates 3a, 3
b is usually made of a steel plate, but other plate-shaped bodies, such as reinforced plastic plates, may be used as long as they have the same strength. joint plate 3a,
3b is a large number of notch openings 4 spaced apart on both side edges.
The joint plates 3a and 3b have elongated members 5 vertically fixed to both end edges thereof to close the entrances of the notch openings.
In this example, the elongated member 5 is made of flat steel and is connected to the joint plate 3.
It is fixed along the width direction of a and 3b. 1 each
A large number of steel bars 6 are arranged between the pair of joint plates 3a, 3b, and both ends thereof penetrate through the joint plates 3a, 3b and are fixed by welding or the like. The elongated member 5 may be fixed perpendicularly to the width direction of the joint plates 3a, 3b as shown in FIG. 2, or a steel bar may be used as the elongated member 5 as shown in FIG. .

As described above, the joint member 1 can be manufactured in the following manner to save on materials.
Economical.

That is, as shown in FIG. 4A, a plurality of continuous cuts 7 having serrated protrusions of the same pitch and shape are made in the plate-like body P, and the tips 8 and base ends 8' of the protrusions are straight lines parallel to each other. Make it. Then, as shown in FIG. 4B, the plate-like body P is separated along the notch 7. In this way, one plate-shaped body P has a fern-shaped joint plate 3 having a large number of notch openings 4.
After preparing a plurality of plates a and 3b, as shown in Fig. 4C, the elongated member 5 is fixed to the joint plates 3a and 3b.
The partition plate 2 is fixed to the joint plates 3a, 3b in the manner described above.

Next, a method for constructing a diaphragm wall using the joint member 1 as described above will be explained.

First, as shown in FIG. 5, a preliminary groove hole 9 is excavated in the ground E, and the joint member 1 is inserted and installed into this preliminary groove hole 9. At this time, sheets 10 for preventing concrete leakage are placed on the ends of the partition plates 2a and 2c, and the joint plates 3
A reinforcing bar cage 11 is fixed in advance to one half of each of a and 3b. Next, the partition plates 2a, 2b, 2
A gutter-shaped protective fence 12 is inserted and installed in the space S between C and the end wall of the leading slot 9, and covers the other half of the joint plates 3a and 3b. Further, a locking material 13 is inserted between the protective fence 12 and the end wall of the slot 9, so that the lateral pressure during concrete pouring is supported by the locking material 13.

Next, concrete is poured and hardened in the area where the reinforcing bar cage 11 is placed, and the preceding unit wall 14 is constructed.

After constructing the leading unit wall 14, as shown in FIG. 4, the locking material 13 is removed and the trailing groove hole 15 including the space S is excavated. After the excavation is completed, the protective fence 12 is removed and the joint plate is removed. After removing slime due to muddy water adhering to the joint member 1 including 3a and 3b and cleaning it, concrete is poured into the trailing groove hole 15 by the same procedure as described above and hardened, and the trailing unit wall 16 is
After that, unit walls are successively constructed and connected in the same manner.

According to the joint member 1 described above, when a vertical shear force is applied to concrete placed in a space surrounded on all sides by the partition plate 2, the steel bar 6, and the joint plates 3a and 3b when viewed from above, , the load is concentrated on the bearing surface 4' of the notch opening 4, and a beam action with the partition plate 2 and the elongated member 5 as fulcrums acts on the joint plates 3a and 3b from the bearing surface 4', and this bearing force (fulcrum reaction force) ) is the shear strength of the joint member. At this time, the concrete is restrained by a large force by the partition plate 2, the steel bar 6, the joint plates 3a, 3b, etc., and the shear resistance force in the vertical direction becomes large, and the bearing force acts effectively on the steel bar 6, so that Shear strength can be increased compared to conventionally used joint members. Incidentally, looking at the shear strength Qc of the joint member in this case, it is expressed by the following equation.

Qc=cQy+hQc Here, cQy is the shear resistance of the steel bar 6, and hQc is the bearing pressure effect of the concrete by the joint plates 3a and 3b.

7 to 9 show another embodiment of the joint member 17, in which reinforcing plates 18 protruding from both sides of the joint plates 3a and 3b are fixed to the periphery of the notch opening 4. The other points are the same as in the previous embodiment. According to such a joint member 17, the shear strength in the horizontal and vertical directions can be further increased, and is extremely effective particularly against earthquake force and earth pressure.

The joint member of the present invention is as described above, and includes a plurality of joint plates having a plurality of notch openings spaced apart from each other on both sides and having a fern-like shape as a whole, arranged vertically at intervals. and a partition plate is fixed vertically and at right angles to both sides of the joint plate, and elongated members for closing the entrances of each notch opening are fixed vertically to both end edges of the joint plate. , since the opposing joint plates are connected with a large number of steel bars, the concrete is restrained by a large force by the partition plates, steel bars, joint plates, etc., resulting in a large shear resistance force in the vertical direction, and the concrete is supported by the steel bars. By applying pressure effectively, the shear strength can be increased compared to conventionally used joint members, and the overall shape is greatly simplified, reducing assembly work, especially the work of fixing joint plates. This can be done with extremely little effort, and since the joint plate is fixed to the partition plate at the edge opposite to the notch opening side, the horizontal cross-sectional shape of the partition plate and the joint plate is T-shaped. As a result, the permeable system path becomes maze-like, which increases the water-stopping effect, and since the joint members are mainly formed from plate-shaped bodies, even if some impact is applied during construction, they will not be affected like conventional joint reinforcing bars. In addition, the attached slime can be easily and reliably cleaned without causing any damage to the joint plate.Furthermore, the joint plate has a number of cut-out openings, so that the connection between the two sides of the joint plate can be made through the cut-out openings. It is possible to improve the circulation of concrete, that is, the concrete can move around better, and high-quality concrete can be placed.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the joint member according to the present invention, Figs. 2 and 3 are perspective views showing other embodiments, and Figs. 4A, 4B, and 4C are manufacturing of the joint member according to the present invention. A plan view showing the main parts of the method, Figures 5 and 6 are cross-sectional views showing the construction state using the joint member, and Figures 7, 8, and 9 are perspective views showing another example of the joint member. be. DESCRIPTION OF SYMBOLS 1, 17... Joint member, 2a, 2b, 2c... Partition plate, 3a, 3b... Joint plate, 4... Notch opening, 5... Elongated member, 6... Steel bar, 7... Notch, 8... Tip of projection, 8'... Base end of protrusion, 18...reinforcement plate.

Claims (1)

[Claims] 1. A plurality of joint plates having a large number of notch openings spaced apart on both sides and having a fern-like shape as a whole are arranged vertically at intervals, and on both sides of the joint plates are arranged vertically. Attach the partition plate at right angles,
An underground continuous wall characterized in that elongated members for closing the entrances of each notch opening are vertically fixed to both end edges of the joint plate, and the opposing joint plates are connected with a large number of steel bars. A joint member in.