JPH07107265B2 - Reinforcing bar cage joining method for continuous underground 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 joining reinforcing steel baskets for underground continuous walls.

[0002]

BACKGROUND ART As is well known, an underground continuous wall constructed as a continuous panel made of reinforced concrete has a laterally long excavation groove formed in the ground, a reinforcing cage is inserted into the excavation hole, and then concrete is excavated into the excavation hole. A reinforced concrete preceding panel is cast in the ground to form it in the ground, and this individual concrete panel is used as a unit element and sequentially connected.

FIG. 6 shows a case where the lap joint method is adopted in the construction of such an underground continuous wall, and the preceding element 1 has a reinforcing bar basket 4 in which a partition plate 3 as an iron plate form is incorporated at the rear end portion. The joint reinforcing bar 5 is projected from the partition plate 3 first. Concrete 6 placed on the side of the preceding element 1
Is stopped by this partition plate 3.

The trailing element 2 is provided with a rebar cage 8 having a joint rebar 7 at its tip. The joint rebar 7 has a narrow width so as to enter the joint rebar 5.

After the concrete 6 of the preceding element 1 is poured, the reinforcing bar basket 8 of the trailing element 2 is arranged in the excavation groove 9, and although not shown, the concrete of the trailing element 2 is poured. The joint reinforcing bars 5 and 7 to be wrapped together are joined by a lap joint.

[0006]

In the conventional joining method shown in FIG. 6, the horizontal reinforcement of the joint rebar 5 and the joint rebar 7 is separated from each other in the horizontal direction for the purpose of joining the rebar cages to each other. There is no reinforcement across the muscles. As a result, when an out-of-plane bending stress β is applied, as shown by α in FIG. 6, there is a risk that splitting cracks will occur across the lap joint portion due to horizontal streaks in the concrete on the trailing element 2 side, and the yield strength will decrease. is there.

The object of the present invention is to eliminate the inconvenience of the conventional example, and to dispose the front end of the reinforcing bar basket of the trailing element at the end of the reinforcing bar basket of the preceding element by a lap joint, and then to move horizontally between the lap joint bars. The purpose of the present invention is to provide a reinforcing bar cage joining method for underground continuous walls that can prevent the adhesive splitting failure by arranging the reinforcing material.

[0008]

In order to achieve the above-mentioned object, the present invention has a horizontal bar on the left and right of the tip of the reinforcing bar basket of the trailing element, which is arranged by a lap joint on the reinforcing bar basket end of the preceding element. The reinforcing material that intersects with is rotatably engaged through the elongated hole, and the end portions of the reinforcing material are axially attached between the left and right horizontal streaks, and this axially attached portion is attached to the trailing element. It is connected by a vertically moving operation rod provided in the tip of the reinforcing bar basket with a link mechanism that rotates in the vertical direction, and when the reinforcing bar basket of the trailing element is installed, the reinforcements are folded so that they are in a horizontal horizontal shape. After arranging and arranging, the shaft attachment part is horizontally moved by the operating rod through the link mechanism so that the reinforcing members are spread out in a straight line shape with each other. The main idea is to project it to the outside of the It is.

[0009]

According to the present invention, after the tip of the cage of the trailing element of the trailing element is placed on the joint reinforcement of the cage of the leading element of the preceding element by the lap joint, the operating rod is moved up and down until that time. The stiffener contained in the element's rebar cage is spread out in a straight line, and the tip of this stiffener projects outside the horizontal bar of the preceding element's rebar cage and is placed across the lap joint. It As a result, since this reinforcing material acts as a width stop material, it can be expected that an increase in splitting fracture proof strength can be expected, and abrupt crack development can be prevented even when the joint portion receives out-of-plane bending stress.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view showing a first embodiment of a reinforcing bar cage joining method for an underground continuous wall of the present invention, and FIG. 2 is a side view of the same. In the figure, 5 is a joint bar of the reinforcing bar basket on the side of the preceding element,
Reference numeral 7 denotes a joint rebar at the tip of the rebar cage 8 on the trailing element side. The joint rebar 7 is a lap joint and has a narrow width so as to enter between the joint rebars 5 as in the conventional example. . In addition, the joint rebar 7 includes a horizontal bar 7a and a vertical bar 7a.
b, and the left and right horizontal streaks 7a in combination with the purse stop 7c.

According to the present invention, the rotary shaft pin 10 is projected from the left and right horizontal bars 7a at the joint reinforcing bar 7 at the tip of the reinforcing bar basket 8 on the trailing element side. The reinforcing material 11 is inserted into the elongated hole 12 provided in the middle of the strip-shaped reinforcing material 11 so that the reinforcing material 11 is rotatably engaged with the horizontal line 7a. Also,
The reinforcing member 11 has its one end axially attached to each other between the left and right horizontal streaks 7a. This axially attached part is formed by passing a vertically extending longitudinal rod 13 through the end of the reinforcing member 11. Constitute. In addition, the reinforcing member 11 corresponds to the horizontal streaks 7a having a plurality of upper and lower stages (it is not necessary to correspond to all the horizontal streaks 7a, but may be every other or every several). The shafts are vertically attached to each other at intervals.

The reinforcing member 11 is a shaft rod in this embodiment.
The tip portion opposite to the coupling side with 13 is configured as a ring body 18, but as shown in FIG. 4 as a second embodiment, the tip portion of the reinforcing member 11 is further directed toward the tip portion of the joint rebar 7. To form an L-shaped hook 19 at a right angle to, or as an L-shaped hook as in the second embodiment as shown in FIG. 5 as a third embodiment. It is also possible to provide a bar 20 having an end with an enormous head and make the entire reinforcing member 11 substantially U-shaped.

A guide tube 14 is attached to one central position of the purse streak 7c, and the guide tube 14 is inserted into the guide tube 14 to make an operating rod.
15 is provided so that it can move up and down. Further, the operating rod 15 and the shaft rod 13 serving as the end shaft mounting portion of the reinforcing member 11 were connected by a link mechanism 17 with an extruding rod 16 having both ends axially mounted.

In this way, after the reinforcing bar basket is hung down and concrete is cast to form the preceding element panel, the reinforcing bar basket 8 of the trailing element is arranged in the excavation groove 9. At this time, Inside the joint reinforcing bar 7, the pushing rod 16 is in the up-down direction, the operating rod 15 and the shaft rod 13 are close to each other, and the reinforcing members 11 are close to each other and folded so as to form a horizontal shape. In this state, the tip of the reinforcing member 11 has a horizontal streak 7
It does not significantly project to the outside of a.

The joint rebar 7 of the rebar cage 8 of the trailing element is inserted between the joint rebars 5 on the leading element side to form a lap joint, and then the operating rod 15 is pulled up or pulled down (in the example of FIG. 2, The pushing rod 16 falls horizontally and the shaft rod 13 moves away from the operating rod 15. This allows reinforcement
The rotary shaft pins 10 serve as fulcrums for pivoting in the horizontal direction to spread the rolls 11 so that they are straight.

Then, as shown in FIG. 3, the tip of the reinforcing member 11 wraps above or below the horizontal bar of the joint reinforcing bar 5 and projects to the outside of this horizontal bar so as to cross the lap joint. Although illustration is omitted, in this state, if concrete is placed on the trailing element side to form the trailing panel, the joint rebar 5 and the joint rebar 7 are mutually restrained by the reinforcing member 11 and the tensile force Will also exhibit sufficient strength.

Also in the case of the second and third embodiments, the first
Similar to the embodiment, detailed description is omitted, but in the case of the second embodiment, even if the expanded reinforcing member 11 does not directly intersect with the horizontal reinforcement of the joint reinforcing bar 5, the hook 19 comes to the outside and the effect of restraint is obtained. In the case of the third embodiment, in addition to the function of the second embodiment, the bar 20 having an enlarged head is arranged so as to cross the lap joint portion, so that a stronger restraining force can be obtained. .

[0018]

As described above, the reinforcing bar cage joining method for underground continuous walls according to the present invention is a lap joint after the tip of the reinforcing bar cage of the following element is arranged at the end of the reinforcing bar cage of the preceding element by a lap joint. A horizontal reinforcing material can be easily and surely arranged between the reinforcing bars, and this reinforcing material can improve the width-stopping effect and prevent the adhesive splitting fracture.

[Brief description of drawings]

FIG. 1 is a first method of a reinforcing bar cage joining method for an underground continuous wall according to the present invention.
It is a top view before setting a reinforcing material showing an example.

[Fig. 2] The first of the reinforcing bar cage joining methods for the underground continuous wall of the present invention
It is a side view before a reinforcing material set showing an example.

[Fig. 3] The first method of joining the reinforcing bar cage to the continuous underground wall of the present invention.
It is a top view after a reinforcing material set showing an example.

FIG. 4 is the second method of the reinforcing bar cage joining method for the underground continuous wall of the present invention.
It is a top view after a reinforcing material set showing an example.

FIG. 5: Third method of reinforcing bar cage joining method for underground continuous wall of the present invention
It is a top view after a reinforcing material set showing an example.

FIG. 6 is a cross-sectional plan view showing a conventional example.

[Explanation of symbols]

 1 ... Leading element 2 ... Trailing element 3 ... Partition plate 4 ... Reinforcing bar basket 5 ... Joint reinforcing bar 6 ... Concrete 7 ... Joint reinforcing bar 7a ... Horizontal reinforcing bar 7b ... Vertical reinforcing bar 7c ... Purse bar 8 ... Reinforcing bar basket 9 ... Excavation groove 10 … Rotating shaft pin 11… Reinforcement 12… Slot 13… Shaft rod 14… Guide tube 15… Operation rod 16… Extrusion rod 17… Link mechanism 18… Annulus 19… Hook 20… Bar

Claims (1)

[Claims] 1. A reinforcing element that crosses a horizontal reinforcing bar at the tip of a reinforcing bar basket of a trailing element, which is disposed as a lap joint on a reinforcing bar basket of a preceding element, is passed through an elongated hole. The end portions of the reinforcing member are movably engaged with each other, and the end portions of the reinforcing member are axially attached to each other between the left and right horizontal reinforcements. Connected by a link mechanism that rotates in the same direction, and when the reinforcing bar basket of the trailing element is installed, the reinforcing materials are folded so that they are mutually horizontal, and after the installation, the operation rod is connected via the link mechanism. An underground continuous wall characterized by horizontally moving the shaft attachment part and expanding these reinforcing materials so that they are straight to each other and projecting the tip of this reinforcing material to the outside of the horizontal bar of the reinforcing bar basket of the preceding element. Reinforcing bar cage joining method.