JPS6146606B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a joint for a diaphragm wall, and particularly to the structure of a joint for a diaphragm wall in which a locking box is used during construction.

In general, an underground continuous wall is constructed by placing a reinforcing bar assembly in an excavated trench, then pouring concrete into the trench to form a reinforced concrete underground wall, and then It is constructed by pouring concrete in the direction of extension. In this way, underground walls constructed through concrete pouring are required to have high bonding strength between underground walls and sufficient water-tightness for their integrity and continuity. .

Conventionally, a reinforcing bar assembly with a joint attached to one side in advance is built in the trench so that the joint is located on the side of the trench where concrete will be poured later, that is, at the joint between the underground walls. , the underground walls are interconnected through the joint. One of the joints used in the construction of this conventional diaphragm wall is a partition plate disposed across the slot;
There is a joint that includes a plurality of joint members made of reinforcing bars attached to the partition plate in a crossing manner.

In the conventional underground continuous wall in which this joint is used, after the reinforcing bar assembly is erected in the excavated trench, a locking box is installed around the part of the joint member on the side where the concrete is to be poured. is inserted, and the locking box and the partition plate of the joint prevent concrete poured into the slot except for the slot side from flowing into the slot side.

Although the joint members are spaced apart in the depth direction of the slot, they are not necessarily aligned in the same vertical plane, which prevents smooth insertion of the locking box into the slot. Therefore, it is necessary to remove the locking box from the joint member by moving it up and down, and sometimes the joint member may be damaged or deformed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to ensure and smooth insertion of a locking box into a trench in the construction of a continuous underground wall, and to increase the strength and provide sufficient locking at the joints between continuous walls. The purpose is to provide a joint that provides water resistance.

The present invention involves placing a reinforcing bar assembly with a joint on one side in a drilled slot, placing a locking box on the joint side of the slot, and then placing a locking box on the joint side of the slot. An underground continuous wall is constructed by pouring concrete into the trench except for the section, constructing an underground wall, removing the locking box, and pouring concrete in the extending direction of the underground wall. The joint includes a partition plate disposed within the slot and across the slot, and a joint attached to a substantially central portion of the partition plate, extending in the depth direction of the slot and mutually connecting with the partition plate. a joint plate that is perpendicular to each other and has a serrated notch extending in the depth direction of the slot on the sides on both sides of the partition plate; a plurality of anchors spaced apart in the depth direction of the slot on one side thereof and fixed to the joint plate at their ends; and on the other side of the partition plate to which the concrete is to be poured. A plurality of reinforcing bars are installed perpendicularly to both sides of the joint plate and across the notch.

The features of the invention will become clearer from the following description of the illustrated embodiments.

As shown in FIG. 1, the diaphragm wall joint 10 according to the present invention is attached in advance to one side of a reinforcing bar assembly 16 formed by combining a plurality of horizontal reinforcing bars 12 and vertical reinforcing bars 14.

The joint 10 includes a partition plate 20 welded to the transverse reinforcing bars 12 of the reinforcing bar assembly 16 via a pair of flanges 18 provided near both ends of the reinforcing bar assembly 16 in the thickness direction, and a partition plate 20 that and a joint plate 22 attached to the section.

The joint plate 22 extends in the height direction of the reinforcing bar assembly 16, that is, in the depth direction of the slot 30 to be described later into which the reinforcing bar assembly is inserted, and is perpendicular to the partition plate 20. The joint plate 22 further has serrated notches 22c extending in the depth direction of the slot 30 on both sides of the partition plate 20.

The joint plate 22 can be formed of a single plate-like member that extends through a through hole (not shown) provided in the center of the partition plate 20 and is welded to the partition plate 20. When the joint plate 22 is made of a single plate-like member, a through hole for the partition plate 20 made of a single plate is provided in the plate-like member, and the partition plate passes through the through hole. The plate member can be attached to 20 by welding. Furthermore, a joint plate 22 made of a single plate member can be welded to the partition plate 20 made of a pair of plate bodies. Furthermore, joint plate 2
2 may be constructed of a pair of plate-like members, and these plate-like members may be welded to the partition plate 20 made of a single plate.

As shown in FIGS. 1 and 2, the joint plate 22 has its tips mutually connected to one part 22a, that is, the part on the side of the reinforcing bar assembly 16 located on one side of the partition plate 20 (on the left side in the figure). A plurality of anchors 24 are attached having bent portions 23 bent in opposite directions, that is, on opposite horizontal and vertical reinforcing bars 12 and 14 sides in the thickness direction of the reinforcing bar assembly 16. The joint plate 22 has a plurality of vertical holes on both sides of the other portion 22b located on the local side (right side in the figure) of the partition plate 20, vertically and spaced apart from each other, and also across the notch 22c. Reinforcing bars 26 are attached.

The joint 10 has the function of interconnecting each unit of the underground wall in the underground continuous wall 28 constructed in the following manner in the extending direction shown by the imaginary line in FIG.

First, the joint 10, which has been previously attached to the reinforcing bar assembly 16, is erected together with the reinforcing bar assembly 16 in the trench hole 30, which has been excavated while being filled with muddy water to prevent the collapse of the hole wall. The joint 10 is arranged in the trench 30 such that the vertical reinforcing bars 26 are located on the trench side 30a on the side where the underground continuous wall 28 is extended. Further, the joint 10 has its partition plate 20 disposed across the slot 30, thereby defining the slot 30 in its length direction.

Next, as shown in FIG. 4, a plurality of locking boxes 32 are placed inside the slot side portion 30a defined by the partition plate 20 under the guidance of the vertical reinforcing bars 26 of the joint 10.
Insert. At this time, the joint plate 22
Since the vertical reinforcing bars 26 are attached to both sides of the other part 22b, the locking box 32 does not hit the joint plate 22, and furthermore, since the vertical reinforcing bars 26 reach from the upper end of the slot 30 to the lower end. During the descent of rocking box 32,
This will guide you and encourage a smooth descent.

After inserting the locking box 32, the slot side 3
The muddy water in the slot 30 except for the slot 0a is removed to the outside of the slot 30, and concrete is placed inside the slot 30 except for the slot side 30a. Concrete is firmly attached to the entire surface of one part 22a of the joint plate made of a plate-like member, and the saw-toothed notch 2
2c will be filled with concrete.

Since the concrete placement area in this slot 30 and the slot side 30a are separated by the partition plate 20 and the locking box 32,
Concrete can be prevented from flowing into the slot side 30a. In this way, first, one unit of underground wall 34 made of reinforced concrete is constructed.

Thereafter, as shown in FIG. 5, a groove hole 30' for an underground wall to be constructed by pouring concrete later into the underground wall 34 is excavated using muddy water in the same manner as described above. After excavating the slot 30', the locking box 32 is pulled out and removed from the slot side 30a, thereby communicating the slot side with the slot 30'.

Furthermore, a reinforcing bar assembly 16 with a joint 10 according to the invention attached to one side is installed in the slot 30'. The other side 16a of the reinforcing bar assembly 16, as shown in FIG. 26
They are placed at intervals.

Further, as shown in FIG. 7, the slot side portion 30a
Then, concrete is poured into the groove hole 30' to construct the next unit of underground wall 34'. thus,
Both underground walls 34, 34' are connected to each other.

A joint plate 22 embedded in the concrete and located at the center in the thickness direction of the underground wall is constituted by a plate-shaped member extending in the depth direction of the groove hole and therefore in the height direction of the underground wall. Since the underground walls 34 and 34' are connected to each other, they form a water stop plate. Similarly to the one part 22a, the other part 22b of the joint plate has concrete firmly attached to its entire surface, and has a serrated notch 22c.
is filled with concrete, and the notch 22c
The concrete filling the vertical reinforcing bars 26 is surrounded by concrete.

Since the joint 10 has an anchor 24 attached to one part 22a of the joint plate and a plurality of vertical reinforcing bars 26 attached to the other part 22b, the underground walls 34, 34'
Sufficient bonding strength is provided in the extension direction.

Another example of a joint is shown in FIG.
Indicated by The other part 22 of the joint plate 22
A flange 3 extending parallel to the partition plate 20 at the tip of b
6, the locking box 32 can be inserted more easily into the slot side 30a under the guidance of the flange 36.

Furthermore, by attaching a sealing material (not shown) to both ends of the slot 30 of the partition plate 20 in the thickness direction, the gap between the concrete placement area of the slot 30 and the slot side 30a is made liquid-tight. It can also be blocked.

According to the present invention, when constructing an underground continuous wall using a locking box, by attaching vertical reinforcing bars to the joint plate of the joint, the locking box can be inserted into the trench without being hooked on the joint plate. It can be inserted smoothly into the Additionally, the vertical reinforcing bars attached to the joint plates increase the joint strength of the underground walls in the direction of their mutual extension.

Further, according to the present invention, the joint plate is installed substantially at the center of the partition plate and perpendicular thereto, and extends in the depth direction of the groove hole and therefore in the height direction of the underground wall. Therefore, it forms a water stop plate at the joint between the underground walls, thereby increasing the water stop performance of the underground continuous wall.

Further, according to the present invention, the serrated notches on both sides of the joint plate are filled with concrete, and a plurality of anchors are embedded in the concrete on the side of one part, and the plurality of anchors are embedded in the concrete on the side of the other part. Since the vertical reinforcing bars are surrounded by the concrete filling the notch, the bonding strength between the joint plate and the concrete, that is, the bonding strength with the underground wall is significantly increased. For this reason, the lack of adhesion strength with concrete, which is the weak point of the plate material applied to improve water-stopping properties at the joints between underground walls, is fully compensated for, and the shearing in the height direction of both underground walls is made up for. Even when external forces such as seismic forces act, the individual vertical movements of both underground walls are effectively suppressed, thereby preventing shear failure.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the joint according to the present invention attached to a reinforcing bar assembly, FIG. 2 is a side view of the partition plate and joint plate of the joint, FIGS. 3, 4, 5, Figures 6 and 7 are plan views showing step by step an example of constructing a diaphragm wall using the joint according to the present invention, and Figure 8 is an example of a joint in which a flange is provided at the tip of the joint plate. FIG. 10, 10': Joint, 16: Rebar assembly, 2
0: Partition plate, 22: Joint plate, 22
a, 22b: one part and the other part of the joint plate, 22c: serrated notch, 26:
Vertical reinforcement, 28: underground continuous wall, 30, 30': trench, 30a: trench side, 32: locking box, 34, 34': underground wall, 36: flange.

Claims (1)

[Scope of Claims] 1. A reinforcing bar assembly having a joint on one side is placed in an excavated slot, and a locking box is placed on the side of the slot on the joint side, and then a locking box is placed on the side of the slot on the joint side. An underground wall is constructed by pouring concrete into the trench except for the sides, and then the locking box is removed and concrete is poured in the extending direction of the underground wall. The structure of the joint of a medium continuous wall includes a partition plate disposed within the slot and across the slot, and a partition plate installed approximately in the center of the partition plate and extending in the depth direction of the slot. and a joint plate that is orthogonal to the partition plate and has serrated notches extending in the depth direction of the slot in the side portions on both sides of the partition plate; A plurality of anchors spaced apart in the depth direction of the slot on one side where the reinforcing bar assembly is located and fixed to the joint plate at their ends, and the concrete of the partition plate being cast. A joint structure for a diaphragm wall, comprising: a plurality of reinforcing bars attached perpendicularly to both sides of the joint plate and across the notch on the other side to be joined. 2. The underground continuous wall according to claim 1, wherein the joint plate is a single plate-like member that extends through a through hole provided in the partition plate and is welded to the partition plate. joint structure. 3. The diaphragm wall joint structure according to claim 1, wherein the joint plate is comprised of a pair of plate-like members welded to both sides of the partition plate. 4. The underground continuous wall according to claim 1, wherein the joint plate has a flange extending parallel to the partition plate at the end portion on the side where the vertical reinforcing bars are attached. Joint structure.