JPS6122688B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for placing concrete in a shear connector part of a continuous underground wall, and more specifically, a method for placing reinforcing bar cages underground using thin steel plates and protective bags whose volume and size can be changed. The method is to place it in close contact with the wall surface to prevent the concrete from going around and reduce the amount of streaks during chiseling work.

Conventionally, when an underground continuous wall is used as the main structure or as a water-stop earth retaining wall and is connected to other structural members, the joint reinforcing bars are made of foam polystyrene a or , deck plate b
The direct bonding method uses these to prevent concrete from going around and reduces chiseling work, and the steel plate c with a reinforcing bar cage for fixing or the cutter d shown in Figures 3 and 4 is installed in advance. There is a method using a so-called sheer connector, such as an embedded indirect joining method.

However, when Styrofoam a shown in Figure 1 is used in these methods, Styrofoam A is light and weak, so it often comes off or lifts up with the slightest impact when erecting reinforcing steel cages e, etc. F rotates around, increasing the number of chiseled parts g, and the installation method is difficult.

Furthermore, metal fittings such as the deck plate b shown in FIG. 2, or materials that prevent concrete from going around with high rigidity, may cause the underground wall surface to collapse when the reinforcing steel cage e is erected. Therefore, the concrete f inevitably goes around, increasing the chiseled portion g, and making it difficult to find the embedded position.

Further, even when the steel plate c and the coupler d shown in FIGS. 3 and 4 are used, the above-mentioned drawbacks are unavoidable.

The present invention was made to solve the above-mentioned conventional problems, and its gist is to install a thin steel plate in the shear connector forming part on the inner surface of the underground wall of a reinforcing bar cage for continuous underground walls. Attachment: Drill multiple holes in the thin steel plate for inserting the joint reinforcing bars, insert the joint reinforcing bars for the shear connector into the holes, bend the ends of the joint reinforcing bars so that they are aligned with the front surface of the thin steel plate, and then A long and narrow protective bag made of a liquid-tight and pressure-resistant material is attached to the front side of the thin steel plate so as to cover the outside of the bent joint reinforcing bars, and in this state the reinforcing bar cage is erected into the underground wall hole. , Inject a liquid into the protective bag and inflate it so that it is in close contact with the inner surface of the underground wall hole and the outer surface of the thin steel plate, and wrap the joint reinforcing bar on the front side of the thin steel plate, and then Continuous underground characterized by placing concrete in a wall hole and excavating the inside of the formed underground wall to remove the protective bag exposed on the inner surface and expose the joint reinforcing bar. The problem lies in the concrete placement method for the wall shear connector area.

An embodiment of the method of the present invention will be described in detail below with reference to the accompanying drawings.

Reference numeral 1 denotes a reinforcing bar cage, and a long thin steel plate 3 of an appropriate width is attached to the shear connector mounting position of the reinforcing bar cage 1 to receive the reaction force of the protective bag 2 and to protect the protective bag 2 during insertion. An optional shear connector with a hole drilled at the attachment position of the joint reinforcing bar 6 is inserted into the steel plate 3 and fixed.

The protective bag 2 is made of a liquid-tight, pressure-resistant material, and is formed into a long and thin rectangular or circular shape of an appropriate size, and is fixed to the thin steel plate 3 with a string, adhesive, or the like.

The reinforcing steel cage 1 with the protective bag 2 installed is installed in the underground wall hole 4, and a liquid 8 such as water or bentonite liquid is pressurized into the protective bag 2 with a pump 9 to expand it, and the underground wall surface is expanded. A protective bag 2 is brought into close contact with a steel plate 3 attached to a reinforcing bar cage 1 and a joint reinforcing bar 6, and the joint reinforcing bar 6 is wrapped in the protective bag 2 to prevent poured concrete 7 from going around. After the poured concrete 7 is hardened and excavated, the liquid in the protective bag 2 that has come out to the surface is discharged, the protective bag 2 is removed, and the joint reinforcing bars 6 are exposed to perform the joining work.

The present invention has a thin steel plate 3 in the reinforcing bar cage 1 as described above.
Since the protective bag 2 is provided on the thin steel plate 3, the fixing is easy and reliable, and there is no damage. Also, since it does not come into contact with the underground wall surface 5 during erection, it is possible to prevent the wall surface from collapsing. Furthermore, since the volume and size of the protective bag 2 can be varied by pressurizing the liquid into the protective bag 2, the protective bag 2 can be completely adhered to the underground wall surface 5, and it is possible to reliably prevent poured concrete from going around and eliminate chiseling work. It has characteristics.

[Brief explanation of the drawing]

Figures 1 to 4 show the conventional shear connector joining method, Figure 1 shows the joining method using styrofoam, and Figure 2 shows the joining method using a deck plate.
Fig. 3 shows a joining method using steel plates, Fig. 4 shows a joining method using a coupler, Figs. Partial side view of the construction site, Figure 6 is a plan view of Figure 5, Figure 7 is a vertical cross-sectional view of concrete being poured, Figure 8 is a cross-sectional view of Figure 7, Figure 9
FIG. 10 is a layout diagram of the protective bag. 1... Reinforced cage, 2... Protective bag, 3... Steel plate,
4...Underground wall hole, 5...Underground wall surface, 6...Joint reinforcing bar, 7...Concrete, 8...Liquid, 9...
…pump.

Claims (1)

[Claims] 1. Attach a thin steel plate to the shear connector forming part on the inner surface of the underground wall of the reinforcing bar cage for continuous underground walls, drill multiple holes in the thin steel plate for inserting the joint reinforcing bars, and insert the shear connectors into the holes. A joint reinforcing bar is inserted, the tip of the joint reinforcing bar is bent along the front surface of the thin steel plate, and a liquid-tight and pressure-resistant material is made so as to cover the outside of the joint reinforcing bar bent on the front surface of the thin steel plate. Attach a long and narrow protective bag consisting of a protective bag, and in this state install the reinforcing bar cage inside the underground wall hole, and inject liquid into the protective bag and inflate it to protect the inner surface of the underground wall hole and the thin steel plate. The joint reinforcing bars on the front side of the thin steel plate are wrapped in a state in close contact with the outer surface, and then concrete is poured into the underground wall hole, and the inner surface is formed by excavating the inside of the formed underground wall. A method for placing concrete at a shear connector part of a continuous underground wall, the method comprising: removing the protruding protective bag to expose the joint reinforcing bars.