JPH06158650A - Method for constructing underground continuous wall - Google Patents

Abstract

PURPOSE:To enhance the withstanding strength and toughness of a joint so as to enhance reliability and to freely adjust the holding force of the horizontal bars of a panel that follows and to prevent the horizontal bars from holding in excess by building a reinforcing cage for the following panel, and widening narrow end horizontal bars, and laying the bars on top of the horizontal bars of the preceding panels without gaps. CONSTITUTION:Channeled guide rails 10 are provided to the vertical insides of the ends of the horizontal bars 5 of a panel that follows. Hooks 9a, 9a formed at both ends of a plate 9 narrower than the width between the unbound horizontal bars 5, 5 are inserted into the guide rails 10 and the horizontal bars 5 are narrowed to such a degree that they can be forcibly restored. The horizontal bars 5 are constructed between the horizontal bars of the ends of the preceding panel and then the plate 9 is extracted from above the ground to return the space between the horizontal bars 5, 5 to initial width.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a continuous underground wall which constitutes a retaining soil, a water stop wall, a foundation structure and the like.

[0002]

2. Description of the Related Art Generally, a continuous underground wall is constructed by excavating a long hole, inserting a reinforcing bar cage into it, and concrete-placing it to divide it into individual panels. The panels will be installed one after another in sequence. And
It is necessary to wrap the reinforcing bars of adjacent panels so that the connecting portions between the panels maintain sufficient connection strength.

FIG. 7 shows an example thereof. In the figure, 1 is a front panel, 2 is a reinforcing bar cage inside thereof, and a horizontal bar 3 for wrap is projected from an end of the front panel 1, while a trailing line is provided. The horizontal widths 5 and 5 at the rear end of the panel reinforcing bar cage 4 are formed such that the widths between their front end portions are smaller than the width between the horizontal widths 3 and 3 of the preceding panel.

In this way, the horizontal stripes 5, 3 are located between the horizontal stripes 3, 3.
The length of the lap is secured by inserting 5 in this case, but in consideration of the ease of erection of the reinforcing bar cage 4 preassembled on the ground, there is a certain distance a between the horizontal bar 3 and the horizontal bar 5. Was there.

[0005]

In such a conventional underground continuous wall as described above, since the horizontal bars 3, 5 of the joint portion are separated by the distance a, as shown in FIG. Sewing cracks may occur and the joint may be brittlely broken.

This destruction occurs after the transverse bar yields when the reinforcing bar ratio is relatively small, and before the transverse bar yields when the reinforcing bar ratio is relatively large.

On the other hand, as shown in JP-A-57-21621, the longitudinal reinforcing bars of the reinforcing bars of the reinforcing bar cage to be built are pivotally attached to the transverse reinforcing bars, and the longitudinal reinforcing bars are star-wrapped. It is proposed that the reinforcing bars are welded in advance and installed, and then the longitudinal reinforcing bars are rotated to span the stirrup reinforcing bars.

However, in such a method, the structure of pivotally attaching the vertical rebars in the wrap portion is troublesome, and the connection between the vertical rebars and the horizontal rebars is weakened, so that a decrease in strength cannot be avoided.

Further, as disclosed in Japanese Patent Laid-Open No. 21621/1982, in the method of constructing an underground continuous wall, elastic protrusions protruding from the lateral edge of the reinforcing bar basket for the preceding panel are contracted inward and crossed. Insert an intervening member made of rebar in the center and lock it,
There is a construction method in which the interposing member is removed after being installed in the trailing panel to open the elastic protrusion outward due to its elasticity, and the bent portion at the tip of the elastic protrusion is entangled with the preceding panel.

However, in such a construction method, there is a possibility that the elastic protrusion is excessively bent and does not return to its original shape.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, and after constructing a reinforcing bar basket for a trailing panel, widen the end lateral bar that was narrow until then without leaving a gap in the lateral bar on the preceding panel side. Overlap, as a result, it is possible to improve the proof stress and toughness of the joint portion and to make it highly reliable, and moreover, it is possible to arbitrarily adjust the degree of flexion of the transverse stripes on the trailing panel side. , It is to provide a construction method of a continuous underground wall that can prevent excessive bending.

[0012]

Means for Solving the Problems In order to achieve the above object, the present invention provides a method for constructing an underground continuous wall in which a horizontal bar projecting from an end of a preceding panel is connected with a horizontal bar of a cage end of a trailing panel by wrapping the horizontal bar. , A channel-shaped guide rail is provided in the vertical direction of the inside at the tip of the horizontal stripe of the trailing panel, and hooks formed at both ends of the plate having a width narrower than the width between the horizontal stripes in an unrestrained state in the guide rail. Inserting this to make the horizontal bar of the cage for this trailing panel narrow enough to be able to reposition, and after installing this between the horizontal bars at the end of the preceding panel, pull out the plate from the ground Return the width to the width, and arrange the vertical bar that reaches the horizontal bar of the reinforcing bar for the leading panel on the outside and the vertical bar that reaches the horizontal bar of the reinforcing bar for the trailing panel on the inside. The vertical stripes on the panel side are both outside the horizontal stripes Place the horizontal stripes on the same plane in the vertical direction so that they are positioned.Further, after pulling out the plate, insert both ends of the push-out tool with a narrowed tip into this guide rail to forcefully spread the horizontal stripes. This is the summary.

[0013]

According to the first aspect of the present invention, when the hooks at both ends of the plate are inserted along the channel-shaped guide rails, the end lateral stripes are forcibly bent to have the same width as the plate. Since it bends, it can be easily inserted between the horizontal bars on the front panel side, and when the plate is removed after insertion, this end horizontal bar is restored by the elasticity of the reinforcing bar and the horizontal bars on the front panel side and the rear panel side automatically Unify. Therefore, if the width of this plate is appropriately selected, the degree of bending of the horizontal stripes on the trailing panel side can be adjusted without losing its elasticity.

According to the second aspect of the present invention, when the end lateral bar is repositioned, the lateral bars on the leading panel side and the trailing panel side overlap each other on the same plane in the vertical direction, so that the distance between the reinforcing bars is narrow. The joints become dense and the joints become dense, and the strength of the joints increases.

According to the third aspect of the present invention, when the lateral stirrup loses its elastic force and does not fully return to its original position even if the restraining member is removed because the squeezing method is too strong, the inside of the channel-shaped guide rail is You can insert both ends of the pusher into it and forcefully spread the lateral streaks. In addition, this pusher is
The horizontal streaks are buried to maintain a stable shape, which also helps improve the strength of the panel joints.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 3 are plan views showing respective steps of the method for constructing a continuous underground wall of the present invention, in which the same constituent elements as those in FIGS. 7 and 8 showing the conventional example are designated by the same reference numerals. .

First, as shown in FIG. 1, the preceding panel has been completed, and the trailing panel is formed so that the combined lattice of horizontal bars 3 and vertical bars 7 extends from the end of the reinforcing bar cage 2 in two rows. It is protruding to the side.

Next, as shown in FIG. 2, the rebar cage 4 for the trailing panel after drilling is assembled, and the rebar cage 4 is preliminarily used as a restraining member on the ground by using the plate 9 with hooks 9a at both ends. On the other hand, a channel-shaped guide rail 10 is provided on the lateral streak 5 side in the vertical direction of the inside, and the hook 9a is inserted into the guide rail 10 to squeeze through the plate 9.

The rebar cage 4 whose ends are squeezed with the wire steel material 6 in this manner is built up to a predetermined depth so that the squeezed portion can enter between the horizontal bars 3 of the preceding panel 1.

When the construction is completed, the plate 9 as the restraint member is pulled out from the upper end of the guide rail 10 so that it can be easily removed from the ground. When the plate 9 is pulled out, the horizontal muscle 5 is elastically restored to the horizontal muscle 3
And overlap in the same plane in the vertical direction.

At this time, the vertical stripes 7 reaching the horizontal stripes 3 are outward,
In addition, the vertical streak 8 that reaches the horizontal streak 5 is arranged on the inner side.
As shown in FIG. 5, these vertical streaks 7 and 8 are both located outside the overlapping portion of the horizontal streaks 3 and 5, and do not interfere.

By the way, even if the squeezing method is too strong, even if the restraining member is removed, the lateral streak 5 loses its elastic force and may not be sufficiently restored to form a straight line. In such cases,
As shown in FIG. 6, the channel-shaped guide rail 10 as described above is attached to the end of the horizontal bar 5, and the both ends of the truss-shaped push-out tool 11 having the recessed tip as shown in FIG. It is only necessary to insert it inside and forcefully spread the lateral streaks 5.

The push-out tool 11 is buried in order to keep the horizontal streaks 5 in a stable shape, and also helps to improve the strength of the joint portion of the panel.

[0024]

As described above, the method for constructing an underground continuous wall of the present invention is a method for constructing an underground continuous wall in which a horizontal bar protruding from the end of the preceding panel is connected to the horizontal bar of the cage end of the trailing panel by wrapping it. In the construction method, the lateral stripes to be wrapped are vertically overlapped with each other and are not separated in the horizontal direction, and as a result, the yield strength and toughness of the joint portion can be improved. Furthermore, it can be safely and easily installed from the ground without changing the structure of the conventional rebar cage.

Moreover, the bending condition of the lateral stripes on the trailing panel side can be arbitrarily adjusted, the excessive flexure of the lateral stripes is prevented, and the elasticity thereof is not lost. It's as simple as putting the hook in and out of the guide rail.

[Brief description of drawings]

FIG. 1 is a plan view showing a first step of a method for constructing an underground continuous wall of the present invention.

FIG. 2 is a plan view showing a reinforcing bar cage for a trailing panel of the method for constructing an underground continuous wall according to the present invention.

FIG. 3 is a plan view showing a second step of the method for constructing an underground continuous wall of the present invention.

FIG. 4 is a sectional view taken along line AA.

FIG. 5 is a front view of an extrusion tool used in the method for constructing an underground continuous wall of the present invention.

FIG. 6 is a plan view showing a usage state of the method for constructing an underground continuous wall of the present invention.

FIG. 7 is a plan view showing a conventional method of constructing a continuous underground wall.

FIG. 8 is a plan view showing a crack generation state in a conventional underground wall construction method.

[Explanation of symbols]

1 ... Leading panel 2 ... Reinforcing bar basket 3 ... Horizontal bar 4 ... Rear panel reinforcing bar basket 5 ... Horizontal bar 6 ... Wire steel 7,8 ... Vertical bar 9 ... Plate 9a ... Hook 10 ... Guide rail 11 ... Extruder 12 ... Width stopper muscle

Claims (3)

[Claims] 1. A method for constructing a continuous underground wall in which a horizontal bar projecting from the end of the preceding panel is connected to the horizontal bar of the reinforcing bar for the trailing panel by wrapping the horizontal bar, and the tip of the horizontal bar of the trailing panel is vertically inward. Provide a channel-shaped guide rail,
Into the guide rail, hooks formed at both ends of a plate having a width narrower than the width between the horizontal bars in the unrestrained state are inserted to make the horizontal bars of the reinforcing rod cage for the trailing panel into a narrow width capable of forcibly returning. A construction method for a continuous underground wall, characterized in that the plate is pulled out from the ground and restored to the original width after being installed between the horizontal stripes at the end of the preceding panel. 2. A longitudinal bar that reaches the horizontal bar of the reinforcing bar basket for the preceding panel is arranged outside, and a vertical bar that reaches the lateral bar of the reinforcing bar basket for the trailing panel is arranged inside, and the front panel side and the rear panel side are arranged. The method for constructing a continuous underground wall according to claim 1, wherein the horizontal streaks are superposed on the same plane in the vertical direction so that the vertical streaks are both outside the horizontal streaks. 3. Construction of a continuous underground wall according to claim 1 or 2, wherein after pulling out the plate, both ends of an extruding tool having a recessed tip are inserted into the guide rails to forcibly expand the lateral streaks. Law.