JPH0362847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vertical joint construction method for continuous underground walls, which is employed when constructing large-scale foundations or other structures with high rigidity.

[Prior art]

In the past, various types of vertical joints between concrete walls have been proposed when constructing continuous underground walls, but the ones that have a good track record of construction are mainly lap joints in muddy water.

Conventionally, the main types of lap joints known are (1) partition iron plate and crushed stone filling method, (2) temporary box method, and (3) joint box method.

As shown in FIG. 58, in the method (1) above, a partition iron plate 9 is used to partition the preceding wall 8 and the area where the following wall is to be constructed, and this partition iron plate 9 is used as a reinforcing bar cage for the preceding wall 8. The horizontal reinforcing bars 10 of the reinforcing bar cage of the preceding wall are extended to the part where the succeeding wall is to be constructed over a length longer than the lap joint length, and the concrete of the preceding wall is poured. In the front, the trailing wall side of the partition iron plate is filled with crushed stone to prevent deformation of the partition iron plate and the movement of the reinforcing bar cage, and after excavating a groove 11 for the trailing wall body, shear reinforcing bars 12 are installed. This is a method in which a reinforcing bar cage 13 for the trailing wall is erected, and the transverse reinforcing bars 14 of the reinforcing bar cage 13 are arranged at intervals inside or outside the transverse reinforcing bars 10 protruding from the preceding wall 8. . However, the above (1)
In the case of the above method, it becomes difficult to remove the crushed stone if cement penetrates into the crushed stone, and it is difficult to confirm that the crushed stone has been removed when excavating the groove for the trailing wall. Since the effective height D1 is small, it is structurally disadvantageous for bending moments.
Furthermore, in the case of method (2) above, if concrete or the like gets around the temporary box, it becomes difficult to pull out the temporary box. Furthermore, in the case of method (3) above, there is a problem that the construction procedure is complicated.

Furthermore, the methods (1), (2), and (3) above have the following common problems.

A When suspending and lowering the reinforcing bar cage on the trailing side, the reinforcing bar cage may come into contact with the lap joint and deform the reinforcing bars, but this cannot be confirmed.
Even if it is known that the lap joint has been deformed, it is impossible to correct the deformation, so it is extremely difficult to ensure the design strength.

B Conventionally, in order to solve problem A above, designs have been made in which the leading side reinforcing bar cage and the trailing side reinforcing bar cage have a margin of space between them. Since the gap with the reinforcing bar cage is about 10 cm, it is disadvantageous in terms of resistance to bending moments. The value of this reduction in yield strength varies depending on the wall thickness, etc., but the calculated strength is 60 to 60% of the strength of the general part.
It is normal for the rate to drop to about 80%, which poses a problem in terms of economic efficiency.

C. As a method to solve the above problem of lap joints,
It is possible to install the vertical joint position of the wall body at a position where the bending moment and shear force are relatively small, but since the vertical joint position of the wall body is often restricted due to construction, it is necessary to solve the above problem. It is difficult.

[Purpose and structure of the invention]

This invention eliminates the above-mentioned problem of overlapping reinforcing bars in vertical joints of continuous underground walls in uncertain muddy water, and instead connects horizontal reinforcing bars in adjacent reinforcing bar cages in the dry space inside the joint box. The purpose of the present invention is to provide a vertical joint construction method for a continuous underground wall that can strengthen the entire continuous underground wall by connecting it by mechanical connection means such as pressure welding, welding, or screw joints through connecting reinforcing bars. The gist of the present invention is to provide a covering constructed by fitting an elastic covering tube 4 into at least one end of a large number of horizontal reinforcing bars 3 in a reinforcing bar cage 2 in a groove provided in the ground 1. Reinforcement cages with cylinders and hollow joint boxes extending vertically are arranged side by side alternately, and underwater concrete 6 is placed in the groove excluding the inside of the joint boxes, and the underwater concrete After the curing time of 6 has elapsed, the inside of the joint box is kept dry, and the horizontal reinforcing bars 3 in the adjacent reinforcing bar cages 2 are welded by pressure welding, welding, screw joints, etc. inside the joint box via the connecting reinforcing bars 7. A vertical joint construction method for a continuous underground wall is characterized in that after the joint is connected by a vertical joint means, concrete 8 is poured into the joint box.

〔Example〕

Next, the present invention will be explained in detail using illustrated examples.

19 to 23 show a covered reinforcing bar cage 15 having an elastic covered tube 4 on one side used in the first embodiment of the present invention, in which a large number of horizontal reinforcing bars 3 extending in the left-right direction are shown. , a large number of vertical reinforcing bars 17 are arranged at intervals in the vertical direction on two parallel vertical planes spaced apart from each other in the front-rear direction, and extend in the vertical direction. Horizontal reinforcing bars 3 and vertical reinforcing bars 17 that are fixed to each horizontal reinforcing bar 3 and are adjacent to each other in the front-rear direction
The vicinity of the intersection of is connected via a stopper reinforcing bar 18, and the reinforcing bar cage 2 is constituted by the large number of horizontal reinforcing bars 3, vertical reinforcing bars 17, and stopper reinforcing bars 18.

One end of a rubber cylinder 20 is fitted onto the outer periphery of one end of a box-shaped covering cylinder main body 19 made of metal or hard synthetic resin and fixed by pressure welding or adhesive, and the other end of the covering cylinder main body 19 A rubber annular packing 21 is fitted and locked to the rubber cylinder 20, and a lid 22 is removably fitted and fixed to the other end of the rubber cylinder 20 to form an elastic covering cylinder 4.
A rubber annular packing 21 of the elastic covering tube 4 is slidably fitted to one end of each horizontal reinforcing bar 3 in the elastic sheathing tube 4 .

24 and 25 show a reinforcing bar cage 16 with sheathing tubes 4 having elastic sheathing tubes 4 on both sides used in the first embodiment of the present invention. A rubber annular packing 21 is slidably fitted to both ends of each horizontal reinforcing bar 3 in the reinforcing bar cage 2.

26 and 27 show a steel joint box 23 used in the first embodiment of the present invention. A bottom plate 25 is fixed, a water hole 26 is provided in the bottom plate 25, an on-off valve 27 is attached, and the case 24 is fixed.
A large number of through-holes 30 for inserting horizontal reinforcing bars are provided in the plates 28 and 29 on both the left and right sides at the same intervals as the intervals between the ends of the horizontal reinforcing bars 3 in the reinforcing bar cage 2, and furthermore, the through-holes 30 are provided in the through-holes 30. Lid 3 with male thread on female thread
1 are screwed together.

1 to 18 show a first embodiment of the present invention using the underwater concrete 5 and steel joint box 23. First, as shown in FIGS. 1 and 2, the preceding elements are shown. The ground 1 in the planned installation area is excavated with a trench excavator using muddy water 32 for preventing collapse of trench walls, and a trench 33 for the preceding element of a predetermined depth is created.
4, the joint box 23 is lifted up and carried, and is lowered while contacting the right end of the groove 33, and the joint box 23 is seated vertically at the bottom of the groove. In this case, in order to prevent the joint box 23 from descending due to the buoyancy of the muddy water 32 in the groove 33, the on-off valve 27 is opened to prevent the muddy water 32 in the groove 33 from collapsing into the joint box 23. The joint box 23 is suspended while flowing into the water.

Next, as shown in FIG. 3 and FIG.
While bringing each elastic sheathing tube 4 into contact with the left side of the joint box 23, the reinforcing bar cage 15 with sheathing tubes is lowered into the groove 33 by the crane 34, and then, as shown in FIGS. 5 to 7, Both ends of the plurality of support beams 35 that straddle the upper part of the groove 33 are placed on a support stand 36 on the ground, and the hanging reinforcing bars 37 connected to the upper end of the reinforcing bar cage 2 are placed on the support beams 35.
The nut 39 is inserted into the center hole jack 38 for level adjustment placed thereon, and is engaged with the hollow piston of the center hole jack 38 by a nut 39.
Adjust the level of the reinforcing bar cage 15 with a covered tube, and arrange the ends of each horizontal reinforcing bar 3 in the reinforcing bar cage 15 with a covered tube so as to face each other in the through hole 30 for passing through the horizontal reinforcing bar in the joint box 23, In this state, the 8th
As shown in the figure and FIG. 9, underwater concrete 5 is placed in the groove 33.

Next, as shown in FIGS. 10 and 11, a groove 40 for the trailing element is provided using muddy water 32, and then, as shown in FIGS. 12 and 13,
The groove 4 is cut by a crane between the reinforcing bar cage 16 with sheathing tube, which has elastic sheathing tubes 4 on both left and right sides, and the joint box 23.
0 and the joint box 2 in the groove 40.
3 and the covered tube-equipped reinforcing bar cage 16 are supported by a level adjustment support device using the center hole jack 38 as described above, and the covered tube-equipped reinforcing bar cage 1 is
6, both ends of each horizontal reinforcing bar 3 are placed so as to face each other in the horizontal reinforcing bar insertion holes 30 in the left and right joint boxes 23, and then, as shown in FIGS. 14 and 15, each joint box 23 is A groove 40 between
Underwater concrete 5 is poured inside.

Next, after the curing time of the underwater concrete 5 has elapsed, the on-off valve 27 is closed and the muddy water inside the joint box 23 is removed by a pump. 16 to 18, connecting reinforcing bars 6 are placed across the ends of each horizontal reinforcing bar 3 in adjacent reinforcing bar cages 2 and fixed by welding, and then elastic coating is applied. After filling the tube 4 with mortar, concrete 7 is cast and filled into the joint box 23.

Next, the excavation of the groove 40 for the trailing element, the lifting and lowering of the joint box 23 and the reinforcing bar cage 16 with covered tube, the connection of the horizontal reinforcing bars 3 with the connecting reinforcing bars 6, and the filling of mortar and concrete 7 are repeated as many times as necessary. Then, construct a continuous earth wall of the required length.

As in the above embodiment, the elastic sheathing tube 4 is attached to the horizontal reinforcing bars 3.
If the elastic covering tube 4 is slidably fitted into the
If there is any misalignment in the lateral positions, it can be easily adjusted so that the lateral positions are aligned.

After suspending the steel joint box 23 into the groove, the reinforcing bar cages 15, 1 with covered tubes are placed along the joint box 23.
6, in order to prevent the reinforcing bar cages 15 and 16 with covered tubes from shifting in the groove width direction, as shown in FIGS. 28 and 29.
A web of a vertical guide member 41 with a T-shaped cross section is fixed by welding to the center of the plates 28 and 29 on both the left and right sides of the joint box 23, and the guide member 41 is used to guide both the front and rear sides of the reinforcing bar cages 15 and 16 with covered tubes. You may suspend it while guiding the end of the horizontal reinforcing bar 3.

When connecting horizontal reinforcing bars 3 of adjacent reinforcing bar cages 2 via connecting reinforcing bars, as shown in FIG. 30, connecting reinforcing bars 6A,
One end of the connecting reinforcing bars 6B may be fixed by welding, and the other ends of each of the connecting reinforcing bars 6A, 6B may be fixed to each other by welding, and as shown in FIG. 31, the ends of the horizontal reinforcing bars 3 are provided with male threads. In addition, male threads may be provided at both ends of the connecting reinforcing bar 6, and both ends of the connecting reinforcing bar 6 and the end of the horizontal reinforcing bar 3 may be connected by sleeve nuts 42. Furthermore, the ends of the horizontal reinforcing bars 3 and the ends of the connecting reinforcing bars 6 may be integrally connected by pressure welding.

As shown in FIGS. 32 and 33, the rubber annular packing 21 is not provided on the sheathing body 19 of the elastic sheathing tube 4, and horizontal reinforcing bars 3 are inserted into the end plates of the sheathing body 19 and fixed by welding. You may. Further, in order to eliminate the possibility that the rubber cylinder 20 is pressed and deformed by the pressure of the muddy water 32 and the underwater concrete 5, the elastic covering cylinder 4 may be filled with granular materials such as sand in advance.

Furthermore, when the covered reinforcing bar cage 16 having the elastic covered tubes 4 on both sides is suspended between the left and right joint boxes 23 that have been previously suspended in the groove,
At least one of the elastic sheathing tubes 4 on both the left and right sides of the reinforcing bar cage with sheathing tube 16 is slidably fitted onto the horizontal reinforcing bars 3, and the elastic sheathing tube 4 is slid as necessary. Then, while bringing the left and right elastic sheathing tubes 4 into contact with the joint box 23, the reinforcing bar cage 16 with sheathing tubes is suspended. However, when the reinforcing bar cage 16 with sheathing tube and the joint box 23 are hung down alternately, the sheathing tube main body 19 of the elastic sheathing tube 4 may be fixed to both ends of the horizontal reinforcing bar 3.

Fig. 34 shows a second embodiment in which the present invention is applied to an L-shaped joint of a continuous underground wall, and shows the outer horizontal reinforcing bars 3A in reinforcing bar cages 16A and 16B with covered tubes arranged at right angles. The end portion and both ends of the L-shaped connecting reinforcing bar 6A are connected by welding, and one end portion of the linear connecting reinforcing bar 6B is connected to the end of the inner horizontal reinforcing bar 3B in each covered reinforcing bar cage 16A, 16B. The other end of the connecting reinforcing bar 6B is fixed to the joint box 23 by welding, and the inclined connecting reinforcing bar 6C is attached to the end of the locking reinforcing bar 43 fixed to each covered reinforcing bar cage 16A, 16B. Although the end portions of are fixed by welding, the other structure is the same as that of the first embodiment.

FIG. 35 shows a third embodiment in which the present invention is applied to a T-shaped joint part of a continuous underground wall, in which reinforcing bar cages 16A with covered tubes are placed opposite each other with a joint box 23 in between.
Both ends of the connecting reinforcing bars 6A are connected by welding to the ends of each of the horizontal reinforcing bars 3A, and the ends of the horizontal reinforcing bars 3B in the reinforcing bar cage 16B with a sheathed tube are arranged at right angles to the reinforcing bar cage 16A with a sheathed tube. One end of the connecting reinforcing bar 6B is fixed by welding, and the other end of the connecting reinforcing bar 6B is fixed to the joint box 23 by welding, but the other configurations are the same as in the first embodiment.

FIGS. 36 to 39 show a fourth embodiment of the present invention. First, FIGS.
As shown in FIG. 7, the reinforcing bar cage 44 with a joint box, which is constructed by inserting the right end of each horizontal reinforcing bar 3 of the reinforcing bar cage 2 into the joint box 23, is inserted into the groove 33 for the preceding element.
Then, as shown in FIGS. 38 and 39, the right end of each horizontal reinforcing bar 3 of the reinforcing bar cage 2 is inserted into the joint box 23, and the left end of each horizontal reinforcing bar 3 of the reinforcing bar cage 2 is inserted into the joint box 23. A joint box and a reinforcing bar cage 45 with a sheathing tube, which are constructed by fixing or slidably fitting an elastic sheathing tube 4 to the end thereof, are configured to be suspended while the elastic sheathing tube 4 is in contact with the joint box 23. However, the other configurations are the same as in the first embodiment.

40 and 41 show a steel joint box 46 used in the fifth embodiment of the present invention, in which two connecting plates 48 perpendicular to the vertical flange plate 47 are arranged inside the vertical flange plate 47. The box unit 50 is constructed by disposing the flange plates 49 at intervals in the width direction of the flanges and fixing them by welding, and by disposing stiffening plates 49 across the inside of each connecting plate 48 and fixing them by welding. , two box units 5
0 are arranged parallel to each other at intervals, a band-shaped cover plate 51 is brought into contact with the inner surface of the connecting plate 48 in each box unit 50, and bolts 52 are inserted through the cover plate 51 from the inside. is connecting plate 4
8, and the cover plate 51 is detachably fixed to the connecting plate 48 by the bolts 52 thereof.

42 to 57 show a fifth embodiment of the present invention.
As shown in Figure 3, the ground 1 on both the left and right sides of the area where the preceding element is to be set is excavated using muddy water 32 with an excavator such as an earth auger to form circular vertical holes 53A and 53B of the required depth. As shown in FIG. 44 and FIG.
3A, 53B, as shown in FIGS. 46 and 47, a solidifying agent made of sodium silicate, cement, etc. is added to the muddy water around the joint box 46, and the mixture is stirred. The joint box 46 is fixed by the solidified muddy material 54, and the excavator uses the muddy water 32 for preventing trench wall collapse at a position a predetermined distance to the right from the vertical hole 53B on the right side. A vertical hole 53C for the preceding element is excavated.

In order to generate the solidified mud 54, solidified mud such as cement-containing mud may be injected into the trench to replace the mud 32, or solidified mud may be used when excavating the trench. The joint box 46 may be lowered into the trench before the hardenable mud solidifies.

Next, as shown in FIG. 48 and FIG.
A tremie pipe (not shown) is inserted into the joint box 46 inserted into the joint box 46, and concrete 55 is placed at the bottom of the joint box 46, and the roots at the bottom of the joint box 46 are poured. After hardening, the joint box 46 is suspended into the vertical hole 53C for the trailing element.

Note that after the foot protection concrete 55 is poured on the inside and outside of the lower part of the joint box 46 to perform foot hardening, the solidified mud 54 may be generated around the joint box 46 as described above. .

Next, as shown in FIGS. 50 and 51, the ground 1 and the solidified mud 54 between the joint boxes 46 on both sides of the part where the preceding element is to be set are excavated by an excavator using the mud 32. Groove 5 with a depth reaching near the level of the upper part of foot protection concrete 55
6A, and cover plate 51 on the groove 56A side of joint box 46 with muddy water 3 for preventing groove wall collapse in groove 56A.
2, concrete 55 is poured into the lower part of the joint box 46 in the vertical hole 53C for the trailing element, and the joint box 46 is
A muddy solidified substance 54 is generated around the .

Next, as shown in FIGS. 52 and 53, the reinforcing bar cage 16 with a covered tube having the structure shown in FIGS. 21, 24, and 25 is brought into contact with the joint box 46 on both sides of the groove 56A. After being suspended into the groove 56A, the underwater concrete 5 is cast into the groove 56A using a tremie pipe (not shown).

Next, in the same way as for the preceding element, the fifth
As shown in FIGS. 4 and 55, the ground 1 and solidified mud 54 between the joint boxes 46 on both sides of the trailing element installation area are excavated using mud to level the upper part of the foot protection concrete 55. After forming a groove 56B deep enough to reach the vicinity, the reinforcing bar cage 16 with a covering tube is suspended into the groove 56B, and then underwater concrete 5 is poured into the groove 56B.

Next, after the curing time of the underwater concrete 5 has elapsed, the muddy water in the joint box 46 in the groove 53B is removed, and then the bolts 52 in the joint box 46 are removed and the cover plate 51 is removed. A part of the concrete of the trailing element is exposed inside the joint box 46, and the elastic covering tube 4
Remove the lid and put it in the state shown in Figure 56.

Next, as shown in Fig. 57, adjacent reinforcing bar cages 2
After the connecting reinforcing bars 6 are arranged across the horizontal reinforcing bars 3 and fixed by welding, mortar is filled in the elastic sheathing tube 4, and concrete 7 is placed between the pair of box units 50 constituting the joint box 46. to be poured.

Next, the excavation of the groove 40 for the trailing element, the lifting and lowering of the joint box 23 and the reinforcing bar cage 16 with covered tube, the connection of the horizontal reinforcing bars 3 with the connecting reinforcing bars 6, and the filling of mortar and concrete 7 are repeated as many times as necessary. Then, construct a continuous underground wall of the required length.

In the case of the fifth embodiment as well, a guide member is attached to the box unit 50 or the cover plate 51 in the joint box 46, and the reinforcing bar cage 1 with the covered tube is guided by the guide member.
6 may be lowered while being guided, and the covered reinforcing bar cage 16 may be accurately installed at a predetermined position.

When carrying out this invention, if the reinforcing bar cage 2 having the stopper reinforcing bars 18 is used, the shearing force applied to the wall can be strongly resisted. Further, by placing reinforcing bars in the joint boxes 23, 46 and pouring concrete, the strength of the vertical joint portion of the continuous underground wall can be further improved. Furthermore, the horizontal reinforcing bars 3 and the connecting reinforcing bars may be integrally connected by pressure welding.

〔Effect of the invention〕

According to this invention, the interior of the joint box is kept dry, and in the dry joint box, the horizontal reinforcing bars 3 of adjacent reinforcing bar cages 2 are welded by a machine such as pressure welding, welding, or threaded joints via the connecting reinforcing bars 6. Since the connection is made using a mechanical connection means, the horizontal reinforcing bars 3 of adjacent reinforcing bar cages 2 can be connected more reliably and strongly than conventional lap joints performed in muddy water, and then concrete 7 is poured into the joint box. This makes it possible to significantly increase the strength of vertical joints of continuous underground walls and improve the reliability of the strength.
It can be easily applied to L-shaped, T-shaped, 10-shaped cross joints, etc., and a reinforcing bar cage with a covered tube is suspended from the grooves on both sides of the joint box to create underwater concrete 5.
After placing the following elements, the work on both sides of the joint box shall be carried out, regardless of the excavation of a trench for the trailing element at another location, the lifting and lowering of a reinforcing bar cage with a covering tube, the underwater concrete pouring, and the lifting and lowering of a joint box. Since the horizontal reinforcing bars 3 in the reinforcing bar cages 2 can be connected, the entire construction period for continuous underground wall construction can be shortened. In addition, the ends of the horizontal reinforcing bars 3 in the reinforcing bar cage 2 that is suspended along the joint box are covered with the elastic sheathing tube 4, so even if the joint box that has already been suspended is slightly inclined, the elastic sheathing tube When lowering the reinforced reinforcing bar cage, the elastic sheathing tube 4 is automatically elastically deformed by the joint box, so that the lifting work can be carried out without any trouble. Since the effective height D ₂ of the thickness does not decrease, the vertical joints in the continuous underground wall do not become weak points, and therefore the joints can be installed at any position depending on the construction convenience, etc.

[Brief explanation of drawings]

1 to 27 show a first embodiment of the present invention, in which FIG. 1 is a longitudinal sectional front view showing a state in which a joint box is inserted into a groove for a leading element provided in the ground, and FIG. Figure 2 is a cross-sectional plan view of the same, Figure 3 is a vertical front view showing the reinforcing bar cage with a sheathed tube being suspended in the groove for the preceding element, Figure 4 is its cross-sectional plan view, and Figure 5 is a cross-sectional view of the sheathed tube. FIG. 6 is a plan view showing a state in which the reinforcing bar cage is supported at a predetermined level, FIG. 6 is a longitudinal sectional front view thereof, FIG. 7 is a longitudinal sectional side view showing a state in which the reinforcing bar cage is supported by a level adjustment support device, and FIG. Fig. 9 is a longitudinal sectional front view showing a state in which underwater concrete is placed in the trench for the leading element; Fig. 10 is a longitudinal sectional front view showing the state in which the trench for the trailing element has been excavated; Fig. 11 12 is a vertical sectional front view showing a state in which the joint box and reinforcing bar cage with covering tube are suspended in the trailing element groove, and FIG. 13 is a lateral plan view thereof.
Fig. 14 is a longitudinal front view showing the state in which underwater concrete is placed in the trailing element groove, Fig. 15 is a cross-sectional plan view thereof, and Fig. 16 is a cross-sectional view showing how horizontal reinforcing bars of adjacent reinforcing bar cages are connected via connecting reinforcing bars. A longitudinal sectional front view showing the state in which the joints are connected and concrete is poured into the joint box, Fig. 17 is a cross-sectional plan view thereof, and Fig. 18 is the first
6 is an enlarged longitudinal sectional front view showing the vicinity of the horizontal reinforcing bar connection part, FIG. 19 is a plan view of a reinforcing bar cage with a covered tube having an elastic covered tube on one side used in the first embodiment of the present invention, and FIG. 20 21 is an enlarged partial longitudinal sectional front view showing a part of the reinforcing bar cage with sheathing tube, and FIG.
23 is a sectional view taken along line A-A in the figure, and B-- in FIG. 21.
24 is a plan view of a reinforcing bar cage with covering tubes having elastic covering tubes on both sides used in the first embodiment of the present invention, FIG. 25 is a partially cutaway front view thereof, and FIG. 26 is a sectional view taken along line B. FIG. 27 is a longitudinal sectional front view of the joint box used in the first embodiment of the present invention, and is a sectional view taken along the line CC in FIG. 26. FIG. 28 is a cross-sectional plan view showing the relationship between the guide member attached to the joint box and the covered reinforcing bar cage, and FIG. 29 is a vertical cross-sectional front view thereof. 30 and 31 are longitudinal sectional front views showing other examples of horizontal reinforcing bar connections in adjacent reinforcing bar cages, FIG. Figure 32 D-D
A line sectional view, FIG. 34 is a cross-sectional plan view showing an L-shaped joint of a continuous underground wall constructed by the method of the second embodiment of the present invention, and FIG. It is a cross-sectional plan view showing the T-shaped joint part of the constructed continuous underground wall. Figures 36 to 39
The figure shows a fourth embodiment of the invention,
FIG. 36 is a longitudinal sectional front view showing a state in which a reinforcing bar cage with a joint box is suspended in a groove for a leading element;
Fig. 37 is a cross-sectional plan view thereof, Fig. 38 is a longitudinal sectional front view showing a state in which the joint box and reinforcing bar cage with covering tube are suspended in the trailing element groove, Fig. 39
The figure is a cross-sectional plan view thereof. FIG. 40 is a partially cutaway longitudinal sectional front view of a joint box used in the fifth embodiment of the present invention, and FIG. 41 is a cross-sectional plan view thereof. 42 to 57 show a fifth embodiment of the present invention, in which FIG. 42 is a longitudinal sectional front view showing a state in which vertical holes are provided on both left and right sides of the portion where the preceding element is scheduled to be installed; Fig. 43 is a cross-sectional plan view of the same, Fig. 44 is a vertical cross-sectional front view showing the joint box suspended in each vertical hole, Fig. 45 is a cross-sectional plan view of the same, and Fig. 46 shows left and right views of the area where the preceding element is to be installed. A vertical sectional front view showing a state in which solidified mud is generated in the vertical holes on both sides and a vertical hole is provided on the right side of the part where the trailing element is planned to be installed. Figure 47 is a cross-sectional plan view thereof, and Figure 48 is the leading element. A vertical sectional front view showing the state in which foot protection concrete has been poured at the bottom of the joint boxes on both the left and right sides of the planned installation area, Fig. 49 is a cross-sectional plan view thereof, and Fig. 50 shows the trench for the preceding element being excavated and the preceding element being installed. Fig. 51 is a vertical cross-sectional front view showing a state in which solidified mud is generated in the vertical hole on the right side of the scheduled part and concrete is poured into the lower part of the joint box in the vertical hole;
Fig. 52 is a longitudinal sectional front view showing a state in which a reinforcing bar cage with a covering tube is suspended in the trench for the leading element and underwater concrete is placed, Fig. 53 is a cross-sectional plan view thereof, and Fig. 54 is the trench for the trailing element. A longitudinal front view showing a reinforcing bar cage with a covering tube suspended inside and underwater concrete being cast, Fig. 55 is a longitudinal sectional plan view thereof, and Fig. 56 is a cross-sectional view showing the joint part with the cover plate of the joint box removed. The plan view, FIG. 57, is a cross-sectional plan view showing a state in which horizontal reinforcing bars in adjacent reinforcing bar cages are connected via connecting reinforcing bars, and concrete is poured into the joint box. FIG. 58 is a cross-sectional plan view showing a conventional wall vertical joint. In the figure, 1 is the ground, 2 is the reinforcing bar cage, 3 is the horizontal reinforcement, 4 is the elastic covering tube, 5 is the underwater concrete, and 6
is connecting reinforcement, 7 is concrete, 15 and 16
17 is a vertical reinforcing bar, 18 is a stopper reinforcing bar, 19 is a covered tubing body, 20 is a rubber tubular body,
21 is a rubber annular packing, 22 is a lid, 23 is a steel joint box, 25 is a bottom plate, 26 is a water hole, 27 is an on-off valve, 30 is a through hole for inserting horizontal reinforcing bars, 31 is a lid, 3
8 is a center hole jack for level adjustment, 41
is a guide member, 44 is a reinforcing bar cage with a joint box, 45 is a reinforcing bar cage with a joint box and a covering tube, 46 is a joint box,
51 is a cover plate, 52 is a bolt, 53A to 53C are vertical holes, 54 is solidified mud, 55 is foot protection concrete, and 56A and 56B are grooves.

Claims (1)

[Claims] 1 In a groove provided in the ground 1, an elastic covering tube 4 is attached to at least one end of a large number of horizontal reinforcing bars 3 in the reinforcing bar cage 2.
Rebar cages with covered tubes and hollow joint boxes extending vertically are arranged side by side alternately in the horizontal direction, and submerged concrete 5 is placed in the groove except for the inside of the joint boxes. is poured, and after the curing time of the underwater concrete 5 has elapsed, the inside of the joint box is kept dry, and the horizontal reinforcing bars 3 in adjacent reinforcing bar cages 2 are pressure-welded through the connecting reinforcing bars 6 within the joint box. A vertical joint construction method for continuous underground walls, characterized in that after the joints are connected by mechanical connection means such as welding or screw joints, concrete 7 is poured into the joint box.