JPH07107266B2 - Method of joining underground continuous walls - 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 for joining underground continuous walls with horizontal reinforcing bar joints.

[0002]

BACKGROUND ART As is well known for underground continuous walls, a horizontally long excavation groove is formed in the ground, and a reinforcing bar basket is inserted into this excavation groove.
Next, concrete is placed in the excavation groove to produce a reinforced concrete panel in the ground, and the concrete panel is used as a unit element and sequentially connected. Then, conventionally, when the continuous underground wall is used as an earthquake-resistant wall of a basement floor, each panel is connected by a crossbar joint construction method or the like for transmitting in-plane force.

Further, as a joint construction method, a horizontal streak lap joint construction method may be adopted as an inter-wall joint construction method capable of transmitting in-plane and out-of-plane forces. This construction method is shown in FIG. 16 and FIG. 17. In the preceding element 1, the joining rebar 5 is projected from the partition plate 3 of the reinforcing bar basket 4 in which the partition plate 3 as the iron plate form is incorporated at the rear end. . This joint rebar 5 is also a rebar basket 4
Similarly, the horizontal streaks 5a and the vertical streaks 5b are combined.
The concrete placed on the side of the preceding element 1 is stopped by this partition plate 3. The trailing element 2 is provided with a reinforcing bar basket 9 having a joining reinforcing bar 8 at its tip. The joint reinforcing bar 8 has a narrow width so as to enter the joint reinforcing bar 5 and is composed of a combination of the horizontal reinforcing bar 8a and the vertical reinforcing bar 8b similarly to the bonding reinforcing bar 5, but the horizontal reinforcing bar 8a is bent and its mutual It is configured to narrow the gap.

After placing the concrete 6 of the preceding element 1, the reinforcing bar basket 4 of the trailing element 2 is arranged in the excavation groove 10, and although not shown, the concrete of the trailing element 2 is placed. Bonding is performed with the joining reinforcing bar 5 and the joining reinforcing bar 8 to be wrapped.

[0005]

In the conventional reinforcing bar joint structure shown in FIGS. 16 and 17, the horizontal bars 5a and 8a, which are joint bars, are simply wrapped to join the reinforcing bars together. When subjected to bending stress, these horizontal streaks on the pulling side may spring outward, and as shown by α in FIG. 16, cracks may occur in the concrete on the trailing element 2 side and the yield strength may decrease.

The splitting fracture by the horizontal streaks 5a and 8a is extremely fragile, and the splitting fracture cannot be prevented even if the amount of the horizontal streaks is increased. In addition, the splitting fracture resistance is positively correlated with the overlapping length of the horizontal streak, and even if the leading panel side horizontal strip and the trailing panel side horizontal strip are separated vertically Then, split fracture occurs.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, to increase the width-retaining effect of the end portion of the joint rebar, and to prevent it from flipping outward easily and surely, and to improve the yield strength of the joint portion. It is to provide a method of joining underground continuous walls.

[0008]

In order to achieve the above object, the present invention has an underground continuous wall in which a joining rebar of a leading end cage bar of a preceding element and a joining reinforcing bar of a trailing end bar of a trailing element are arranged by a lap joint. In the joining method of No. 2, when arranging these joining rebars in an overlapping manner, place a bar arranging machine that keeps the reinforcing bar by hoop or U-shaped in the horizontal state at appropriate intervals in the center of the excavation groove. The gist of the present invention is to push out the reinforcing bars in the horizontal direction with a wedge-shaped push-out tool that is hung from the ground and to arrange the reinforcing bars so as to cross over the horizontal bars of the lap joint.

[0009]

When the horizontal lap joint portion receives an out-of-plane force, the horizontal reinforcing bar of the joining reinforcing bar of the preceding element and the horizontal reinforcing bar of the joining reinforcing bar of the succeeding element move so as to separate from each other in the horizontal direction.
According to the present invention, the bar arrangement machine is arranged at the center of the horizontal bar of the left and right lap joints, that is, at the center position of the excavation groove, and the reinforcing bar is pushed out in the horizontal direction by the wedge-shaped pusher suspended from the ground. The reinforcing bar can be arranged so as to cross over the horizontal bars of the jointed reinforcing bars and cross each other. As a result, since this reinforcing bar acts as a width stop bar, it can be expected that an increase in splitting fracture resistance can be expected, and a rapid cracking can be prevented even if the joint portion receives an out-of-plane bending stress.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows the first method of joining underground continuous walls of the present invention.
FIG. 2 is a cross-sectional plan view before joining showing an embodiment, and FIG. 2 is a cross-sectional plan view after joining, in which the same components as those in FIGS. 16 and 17 showing the conventional example are designated by the same reference numerals.

1 and 2 show a first embodiment of the present invention. On the side of the preceding element 1, a partition plate 3 of a reinforcing bar cage 4 having a partition plate 3 as an iron plate frame at the rear end is installed from the partition plate 3. First, the joint reinforcing bar 5 formed by the combination of the horizontal reinforcing bar 5a and the vertical reinforcing bar 5b is projected, but the horizontal reinforcing bar 5a of this joint reinforcing bar 5 is assumed to be narrower than the width of the main body portion of the reinforcing bar basket 4, and will be described later. As described above, it is made to enter between the horizontal reinforcements 8a of the joint reinforcement 8 at the tip of the reinforcement basket 9 on the trailing element 2 side.

More specifically, a narrowed portion 4a is formed which narrows the mutual spacing of the horizontal bars of the main body portion of the reinforcing bar basket 4. The partition plate 3 is arranged at the end of this narrowed portion 4a, and the partition plate 3 is located in front of the partition plate 3. The width between the horizontal reinforcing bars 5a of the joint reinforcing bar 5 is maintained at the width narrowed by the narrowed portion 4a.

Further, flange plates 14 in a direction orthogonal to the partition plates 3 are provided at both ends of the partition plate 3 with a required width so that the partition plate 3 has an H-shape as a whole. Since the partition plate 3 is equal to the width of the excavation groove, the flange plate 14 is in contact with the excavation groove wall and is in a position parallel to the excavation groove wall.

On the other hand, the trailing element 2 is provided with a reinforcing bar cage 9 provided with a joining reinforcing bar 8 at its tip. The distance between the horizontal reinforcing bars 8a of the joining reinforcing bars 8 at the tip of the reinforcing bar basket 9 is the reinforcing bar cage. It is the same as the interval of the horizontal stripes of the main body portion of 9.

Next, the bar arrangement machine 16 used in the present invention will be described. As shown in FIGS. 5 to 8, this is a rack body in which a rib-shaped rail 17 is horizontally formed inside a wall body corresponding to an H-shaped flange that is open on the left and right.
The U-shaped reinforcement bars 11 are held horizontally in the upper and lower stages at appropriate intervals. The reinforcing bar 11 has a U-shaped opening facing outward, and the reinforcing bar 11 is attached to the vertical axis member 12 in a trapezoid shape with a vertical interval. Further, the reinforcing bar 11 formed by the U-shaped bar can be formed by forming a bulging head 11a at the open end thereof and then bulging the head 11a by stud welding. The vertical axis member 12 penetrates the innermost deepest part of the reinforcing bar 11, and the reinforcing bar 11 is fixed and attached by welding. The vertical axis member 12 may be made hollow by using a pipe in order to reduce the weight of the reinforcing bar 11 as a whole.

On the side of the preceding element 1, the reinforcing bar basket 4 with the partition plate 3 is hung in the excavation groove and the concrete 6 is cast to form the preceding panel. The cast concrete is stopped by the partition plate 3. . After the concrete 6 of the preceding element 1 is cast, the reinforcing bar basket 9 of the following element 2 is arranged in the excavation groove 10. At that time, the horizontal reinforcing bar 8a of the joint reinforcing bar 8 of the reinforcing bar basket 9 is located outside the horizontal reinforcing bar 5a of the reinforcing bar joint 5 to form a lap joint. Further, the tip of the horizontal streak 8a enters between the flange plate 14 and the horizontal streak 5a.

In this way, as shown in FIG. 1, the bar arrangement machine 16 accommodating the reinforcing bar 11 is provided with the horizontal bar 5a and the horizontal bar 8
It is arranged between the left and right ones of the lap joints of a, that is, at the center position of the excavation groove 10. Then, as shown in FIG. 7, a wedge-shaped push-out tool 21 is suspended from the ground, and the reinforcement bar 11 is
Push horizontally. As a result, extruded reinforcement bars
11 is the horizontal bar 5a and 8a of the lap joint protruding from the bar arrangement machine 16
Are arranged so as to cross over each other. The upper and lower positions of the reinforcing bar 11 are offset from the positions of the horizontal bars 5a and 8a so that they are placed on the horizontal bars 5a and 8a.

Although illustration is omitted, in this state, if concrete is placed on the trailing element 2 side to form a trailing panel, the joining rebar 5 and the joining rebar 8 to be wrapped are joined, and the hoop streak is stopped by the width. Acts as a muscle. Also, the vertical axis material
If a pipe is used for 12, the inside may be filled with mortar.

FIGS. 3 and 4 show a second embodiment of the present invention, in which a reinforcing bar 13 of a horizontally elongated elliptical hoop is used in place of the reinforcing bar 11 of the U-shaped bar. As in the first embodiment, the reinforcing bar 13 formed by the hoop bar is attached to the vertical axis member 12 in a trapezoid shape with a vertical interval.

In the case of using the reinforcing bar 13 of the hoop, the horizontal bar 5a of the lap joint is used as shown in FIG.
After arranging so as to cross over each other and 8a,
As shown in FIGS. 9 and 10, if a thin-walled pipe 18 having a sharp tip is inserted on the side opposite to the vertical axis member 12, the structure becomes stronger. The pipe 18 may also be filled with mortar inside.

11 to 15 show a third embodiment of the present invention, in which the bar arrangement machine 19 incorporates an extruding device 20.
As shown in FIG. 12, the push-out device 20 has a structure such as a knitting machine in which a claw-shaped push-out bar 20a successively moves in and out of a wedge-shaped shuttle 20b that moves vertically.
In the figure, 20c is a guide groove of the claw-shaped push-out bar 20 provided in the bar arrangement machine 19.

The operation of the bar arrangement machine 19 is shown in FIG. 13. The reinforcement bar 13 formed by the hoop bar is placed on the pushing bar 20a of the bar arrangement machine 19.
Then, as shown in FIG. 7, the reinforcing bars 13 are pushed out from the bar arranging machine 19 in order from the top by a wedge-shaped pushing tool 21.
After the reinforcing bar 13 is provided, the shuttle 20b is moved up and down to sequentially pull in the push-out bar 20a, and the bar arrangement machine 19
Collect. In this embodiment, since the bar arrangement machine 19 has the pushing device 20, the reinforcing bar 13 can be surely pushed out and arranged.

When the horizontal lap joint portion receives an out-of-plane force, the horizontal reinforcement 5a of the connecting rebar 5 of the preceding element 1 and the horizontal reinforcement 8a of the connecting rebar 8 of the trailing element 2 move to separate in the horizontal direction. However, in any of the first to third embodiments, not only the reinforcing bar 11 or 13 acts as a width stop bar, but the partition plate 3 having an H shape as a whole works, and the flange plate at the end of the partition plate 3 14 acts as a restraint by restraining this joint from the outside. As a result, it can be expected that the split fracture proof stress will increase.

Further, a flat bar 15 made of flat steel is attached to the tip of the horizontal bar 5a of the joining reinforcing bar 5 of the preceding element 1 and the end of the horizontal bar 8a of the joining reinforcing bar 8 on the trailing element 2 side to make it stronger. You can also do it.

[0025]

As described above, the method for joining underground continuous walls of the present invention is an underground continuation in which the joining rebar of the preceding element reinforcing bar basket end and the joining element of the trailing element reinforcing bar basket end are arranged by a lap joint. In the method of joining walls, it is possible to easily and reliably raise the width stop effect of the joining reinforcing bar tip to prevent it from popping outward, and increase the adhesive force to concrete and improve the yield strength of the joint. It is possible.

[Brief description of drawings]

FIG. 1 is a transverse plan view before joining showing a first embodiment of a method for joining underground continuous walls according to the present invention.

FIG. 2 is a cross-sectional plan view after joining showing the first embodiment of the method for joining underground continuous walls of the present invention.

FIG. 3 is a transverse plan view before joining showing a second embodiment of the joining method for underground continuous walls of the present invention.

FIG. 4 is a cross-sectional plan view after joining showing a second embodiment of the method for joining underground continuous walls according to the present invention.

FIG. 5 is a plan view of the bar arrangement machine.

FIG. 6 is a side view of the bar arrangement machine.

FIG. 7 is a vertical sectional front view of the bar arrangement machine.

FIG. 8 is an enlarged transverse plan view of the bar arrangement machine.

FIG. 9 is a plan view showing a pipe arrangement.

FIG. 10 is a side view showing a pipe arrangement.

FIG. 11 is a transverse plan view before joining showing a third embodiment of the joining method for underground continuous walls of the present invention.

FIG. 12 is a side view of an extrusion device used in a third embodiment.

FIG. 13 is a plan view showing the operation of the extrusion device used in the third embodiment.

FIG. 14 is a side view showing the operation of the extrusion device used in the third embodiment.

FIG. 15 is a cross-sectional plan view after joining showing a third embodiment of the method for joining underground continuous walls according to the present invention.

FIG. 16 is a cross-sectional plan view showing a conventional example.

FIG. 17 is a vertical sectional side view showing a conventional example.

[Explanation of Codes] 1 ... Leading element 2 ... Trailing element 3 ... Partition plate 4 ... Reinforcing bar basket 4a ... Drawing section 5 ... Joining rebar 5a ... Horizontal bar 5b ... Vertical bar 6 ... Concrete 8 ... Joining bar 8a ... Horizontal bar 8b … Vertical bar 9… Reinforcing bar basket 10… Drilling groove 11… Reinforcing bar 12… Reinforcing bar 13… Reinforcing bar 14… Flange plate 15… Flat bar 16… Rebar 17… Extruder 18… Pipe 19… Rebar 20 ... Extrusion device 20a ... Extrusion bar 20b ... Shuttle 20c ... Guide groove 21 ... Extrusion tool

Claims (1)

[Claims] 1. A method of joining underground continuous walls in which a joining rebar of a preceding element reinforcing bar basket end and a joining rebar of a trailing element reinforcing bar basket end are arranged by a lap joint, and these joining rebars are arranged in layers. In case of hoop muscle or U
A laying machine that keeps the reinforcing bars by the horizontal reinforcements in the upper and lower stages in a horizontal state at appropriate intervals is arranged at the center of the excavation groove, and the reinforcing bars are pushed out horizontally by the wedge-shaped pusher that is suspended from the ground, and the lap joint is formed. The method for joining underground continuous walls, characterized in that the horizontal stripes are arranged so as to cross over and cross each other.