JPS61142221A - Construction of underground wall - Google Patents

Abstract

PURPOSE:To exactly support horizontal forces to be applied by a method in which a bearing wall, a form box, and a reinforcing bag cage are set in a trench, the bearing walls on both ends of the form box are connected with tie rods, concrete is placed into the form box, and cover plates are set in front of the excavating direction. CONSTITUTION:A given depth of trench 1 is excavated in the ground, and a form box 2 consisting of a bearing wall 3 and side plates 4 and reinforcing bars 6 are integrally penetrated into the trench 1. The form box 2 is fixed with tie rods 10 through the wall 3 by using nuts 11. Concrete 13 is placed in the rare part of the excavating direction of the box 2, and cover plates 14 are set in front of the excavating direction of the box 2 to close the trench 1. The ground in front is excavated. The underground wall can thus be exactly constructed without causing the displacement of the form box because of support by the tie-rods and can withstand the horizontal forces such as soil pressure, etc.

Description

[Detailed description of the invention] Industrial applications This invention relates to a method of constructing underground walls.

Prior Art Conventionally, when constructing a reinforced concrete earth retaining wall, a construction method has been adopted in which a reinforcing cage is suspended one panel at a time and concrete is poured. The problem with this construction method is that the reinforcing bars are not connected at the joints,
Therefore, it was not possible to sufficiently resist horizontal forces caused by water pressure, earth pressure, etc.

In order to solve these problems, the Special Publication Publication No. 47-331
The invention described in Publication No. 0 has been developed.

In this invention, the end of the reinforcing bar cage is made to protrude from a protective measure having a U-shaped cross section, the reinforcing bar cage and the protecting measure are suspended in a groove, and a closing plate is inserted into the protective measure to protect the end of the reinforcing bar. do. Concrete is poured behind the protective measure in the direction of travel, and after the concrete hardens, the closing plate is pulled out and the next reinforcing cage is lowered. It is overlapped with the end of the existing reinforcing bar cage inside the protective cylinder to strengthen the connection of the spliced part.

Problems to be Solved by the Invention Problems to be solved by the invention as described above are as follows.

■ When concrete is poured, the lateral pressure of the concrete is applied to the protective measures, and unless the concrete has a reasonable weight, the protective measures will be misaligned, making it impossible to perform accurate construction.

@ Because the poured concrete flows through the gap between the ground and the side plate of the protection tube and flows into the protection tube, a closing plate had to be inserted at the tip of the protection tube.

Means for Solving the Problems The method for constructing an underground wall according to the present invention includes a formwork box having a substantially U-shaped cross section in a trench excavated underground, and reinforcing bars penetrating the bearing wall of the formwork box. Insert the mold box, connect the previously inserted form box with a tie rod, pour concrete behind the form box so that the lateral pressure of the concrete is supported by the tie rod, and use sealing material to seal between the side plate and the ground. The above problem is solved by preventing the inflow of concrete.

In addition, a cover plate that closes the groove is placed at the tip of the support extending from the bearing wall in front of the form box in the excavation direction, crushed stone is buried in front of the cover plate in the excavation direction, and crushed stone is placed behind the form box. The lateral pressure of the installed concrete is supported by tie rods and crushed stone.

EXAMPLE One of the inventions according to this application will be explained in accordance with the construction order based on an example shown in FIGS. 1 and 2.

<1> Trench excavation A trench 1 of the required depth is excavated into the ground. The width of trench 1 is the same as the width of the underground wall to be constructed.

<2> Insert the form box 2 into the insertion groove 1 of the form box. The formwork box 2 includes a bearing wall 3 and two side plates 4 extending from both ends of the bearing wall 3 in the direction of excavation progress.
, 4 in a substantially U-shaped cross section. The width of the bearing wall 6 is approximately the same as the width of the groove 1. The side plates 4, 4 are made to protrude slightly in the direction of excavation progress than the bearing wall 3, and a sealing material 5 is attached to the rear end thereof in a continuous manner in the vertical direction.

The sealing material 5 is made of an elastic material such as rubber.

Reinforcing bars 6 are connected to the formwork box 2. The reinforcing bars 6 are assembled in advance vertically and horizontally, and their tips penetrate through the bearing wall 3 and are positioned between the side plates 4, 4. Rebar 6
is maintained at a distance from the side plate 4 of the formwork box 2 by a spacer 7. In the embodiment, L-shaped steel is used as the spacer 7.

Further, deformed reinforcing bars 8 are made to penetrate through the bearing wall 3 and protrude from the front and back surfaces. A nut 9 is fixed to the tip of the deformed reinforcing bar 8.

The formwork box 2 and the reinforcing bars 6 having the above-described configuration are inserted into the groove 1 together.

<3> The formwork box 2 connected by the tie rod is connected to the formwork box 2 and tie rod 10 inserted in advance.
Connect by. The tie rod 10 is the bearing wall 3 of the formwork box 2
is passed through and fixed with a nut 11. 12 is a tie rod reinforcing bar.

<4> Concrete pouring Concrete 13 is poured behind the form box 2 in the direction of excavation progress. The sealing material 5 prevents the water from flowing into the gap between the side plate 4 of the formwork box 2 and the ground.

The lateral pressure of the concrete 13 applied to the bearing wall 3 is supported by tie rods 10.

<5> Extension excavation of the groove A cover plate 14 is positioned in front of the form box 2 in the excavation direction to close the groove 1. The cover plate 14 is attached such that one end thereof is perpendicular to a support portion 15 fixed to the bearing pressure wall 3 and extending forward in the excavation direction. Both ends of the cover plate 14 extend to the inner surfaces of the side plates 4, 4 of the form box 2, or to a position close to the ground. Cleaner guides 16 are attached to the front and back surfaces of the support portion 15 in the vertical direction, respectively. In the embodiment, an H-shaped steel is fixed as the cleaner guide 16.

The groove 1 is extended by excavating the front of the cover plate 14.

The excavated soil is prevented from entering the formwork box 2 by the cover plate 14.

The cleaning machine is run using the cleaning machine guide 16 of the support part 15 to clean the reinforcing bars 6 in the formwork box 2.

<6> The cover plate 14 integrated with the concrete pouring support part 15 is removed, and the reinforcing bar 6 integrated with the form box 2 is suspended into the groove 1.

Since the reinforcing bars 6 protrude into the form box 2, the reinforcing bars 6 overlap each other.

In the above state, concrete 13 is poured into groove 1 as described above. Since the reinforcing bars 6 are overlapped at the concrete joint, it is possible to sufficiently withstand horizontal forces caused by earth pressure and the like.

<7> Another embodiment of the invention Next, another embodiment of the invention shown in FIGS. 6 and 4 will be described.

What is shown in FIG. 3 is a structure in which the lateral pressure of the concrete IJ-t 15 is supported by crushed stones 17 buried in front of the tie rods 10 and the cover plate 14.

That is, guide grooves 18 extending vertically are formed on the left and right sides of the surface of the bearing wall 3 of the formwork box 2, and in the guide grooves 1, guides protruding parallel to the left and right sides of the support portion 15 of the cover plate 14 are formed. The guide plate 14 is installed by fitting the parts 19 into each other before pouring the concrete 15 behind the formwork box 2.

Incidentally, a sealing material 20 is provided continuously projecting in the vertical direction at both left and right ends of the cover plate 14.

Crushed stone 17 is buried in front of the cover plate 14, and then concrete 13 is poured behind the form box 2. The lateral pressure of concrete 13 is supported by crushed stone 17 via tie rods 10, support portions 15, and cover plate 14.

After hardening of concrete 16, crushed stone 17, cover plate 1
4. Take out the support part 15 and guide part 19 from the groove 1, and perform the concrete pouring work as described above.

Furthermore, FIG. 5 shows another embodiment in which a kite groove 21 is formed on the surface of the bearing wall 3 of the formwork box 2, a bracket 22 at the tip of the support part 15 is locked, and the cover plate is fixed. 14 is made easy to install and remove.

Effects of the Invention Since the present invention has the above configuration, the following effects can be obtained.

■ Since the reinforcing bars are overlapped at the joints of the concrete, it can sufficiently withstand horizontal forces such as those caused by tonosho.

@ Since the lateral pressure of concrete is supported by tie rods, accurate construction is possible without shifting the formwork box, even if it is lightweight made of thin steel plate.

θ The sealing material prevents concrete from flowing into the space between the side plate of the formwork box and the ground, so concrete does not flow into the formwork garden.

Also, since the lateral pressure of the concrete is supported by the tie rods and by the buried crushed stone via the support section and cover plate, the form box can be supported more firmly.

[Brief explanation of drawings]

1 and 2 are construction order plan views of one embodiment of one invention related to this application, FIGS. 5 and 4 are construction order plan views of an embodiment of the other invention, and FIG. FIG. 7 is a plan view of another embodiment. 1. Groove, 2. Form box, 3. Bearing wall, 4. Side plate,
5. Sealing material, 6. Reinforcing bar 7. Spring spacer, 10
・・Tie rod, 13・φ concrete, 14・・Cover plate, 15・・Support part, 16・・Kite for cleaning machine, 17・・・Crushed stone. il figure

Claims (2)

[Claims] (1) A trench of a required depth is excavated in the ground, and a formwork box with a substantially U-shaped cross section consisting of a bearing wall and two side plates extending in the excavation progress direction from both ends of the bearing wall, and the mold Inserting a reinforcing cage into the groove that penetrates the bearing wall of the frame box and whose tip is located between the both side plates,
The bearing walls at both ends of the formwork box are connected by tie rods, and the lateral pressure of concrete acting on the bearing walls is supported by the tie rods, and concrete is poured behind the formwork box in the direction of excavation progress, and a sealing material is applied. This prevents concrete from flowing into the gap between the side plate and the ground, and furthermore, a cover plate that closes the groove is placed at the tip of the support extending from the bearing wall at the front of the formwork box in the excavation direction, and the front of the cover plate is A method of constructing an underground wall, which is characterized by excavation. (2) A trench of a required depth is excavated in the ground, and a form box with a substantially U-shaped cross section consisting of a bearing wall and two side plates extending in the excavation progress direction from both ends of the bearing wall, and the mold Inserting a reinforcing cage into the groove that penetrates the bearing wall of the frame box and whose tip is located between the both side plates,
The formwork box connects the bearing walls at both ends with tie rods, and a cover plate that closes the groove is placed at the tip of the support part extending from the bearing wall at the front of the formwork box in the direction of excavation. Crushed stone is buried in the front direction, concrete is placed behind the formwork box in the excavation direction, and sealing material is used to prevent concrete from flowing between the side plate and the ground.The lateral pressure of the concrete is controlled by tie rods and supporting parts. A method for constructing an underground wall characterized by supporting it with crushed stone through a cover plate and excavating in front of the cover plate after the concrete hardens.