JPH07145628A - Method of constructing concrete retaining wall - Google Patents

Abstract

PURPOSE:To reduce the transfer weight to facilitate haulage to the construction site, facilitate the works of the construction site and make it rapid to shorten the construction period and reduce the cost. CONSTITUTION:A buried steel rod 14 embedded in a foundation concrete C at the lower side is provided in a semi-precast concrete slab 11 from which reinforcements are exposed at the rear face side of concrete 15. Two semi- precast concrete slabs are unified by a connection steel rod 12 with a distance at the rear side. And an erecting metal fitting 16 is attached to a nut 13 buried in the surface of the lower part of the semi-precast concrete slab 11. In this way, the concrete slab is erected on the leveling concrete B of the foundation and the buried steel rod 14 is embedded in the foundation concrete C placed on the leveling concrete B and further, concrete D is poured between the two semi-precast concrete slabs 11.

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 concrete retaining wall which is erected on the lower side of a slope to prevent the slope from collapsing or to fill the inside with earth to form a flat land. .

[0002]

2. Description of the Related Art A conventional method for constructing a concrete retaining wall is as follows. Assembling the concrete reinforcing bar of the retaining wall on the outside of the frame, and then constructing the formwork forming the outside part of the retaining wall
Concrete was poured between the inner and outer molds, and after the solidification, the molds were removed.

This construction method of the retaining wall is not only a long work period and a long construction period, but also a dangerous work since the work of constructing the formwork, assembling the reinforcing bars and the like are all performed on site. At the same time, since the work requires skill, a skilled worker is required, and the work cost increases, so that there is a drawback that the work is expensive.

[0004] In order to solve this problem, a method has been used in which the concrete of the retaining wall and the reinforcing bar are formed in advance in the factory, and the reinforcing bar is erected on site. Two examples of retaining walls made of precast concrete formed in this factory will be described below with reference to FIGS. 5 and 6, and FIGS. 7 and 8.

In the retaining wall of FIGS. 5 and 6, legs 3 whose bottom end height can be adjusted by bolts 2 are provided on the left and right lower surfaces of the retaining wall main body 1 made of concrete, and the retaining wall main body 1 is also provided.
In the concrete supporting wall 4 provided on the back side of the, the leg 5 having a constant height is provided on the lower surface on the side opposite to the retaining wall 1, and the lower surface of the supporting wall 4 is embedded in the basic concrete. The reinforcing bar 6 fixed to the foundation concrete is refracted and exposed.

This retaining wall is erected at the installation position of the retaining wall,
After the retaining wall main body 1 is horizontally inclined by the rotation of the bolt 2 of the leg 3 and the retaining wall main body 1 is slightly tilted rearward, the lower portions of the retaining wall main body 1 and the supporting wall 4 are embedded in the basic concrete. Concrete construction is performed as described above, and the construction of the retaining wall is completed.

In addition, in the retaining wall shown in FIGS. 7 and 8, a bottom 8 made of concrete is provided at the lower end on the back side of the retaining wall main body 7 made of concrete. The upper surface and the rear surface of the retaining wall main body 7 are connected and reinforced by a supporting wall 9. This retaining wall is one in which the foundation concrete 10 and the retaining wall are integrated by pouring the foundation concrete 10 up to the upper surface of the bottom 8 or more after being set up at the installation position of the retaining wall.

[0008]

In the conventional concrete precast concrete retaining wall as described above, since the entire retaining wall is integrally formed of precast concrete, the weight of the retaining wall becomes large and transportation from the factory to the construction site is difficult. It was very difficult to do so, and even at the construction site, it was not easy to stand the retaining wall at a predetermined position and install it at a predetermined angle.

Therefore, the width of the precast concrete retaining wall in the width direction must be reduced,
The means for connection with the adjacent precast concrete retaining wall, as well as the time of connection, and also the strength of this connection, have been a problem.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to construct a concrete retaining wall construction site by integrating two semi-precast concrete plates with exposed reinforcing bars on the back surface. By transporting it to the building and pouring concrete between the two semi-precast concrete plates after standing, facilitating transportation to the construction site and standing up work by reducing the transport weight, and facilitating construction work at the construction site. The purpose is to provide a method for constructing a concrete retaining wall that can speed up, shorten the construction period, and reduce the construction cost.

The method of constructing a concrete retaining wall of the present invention is intended to achieve the above-mentioned object, and means for exposing a part of the reinforcing bar to the back side and burying the reinforcing bar in the concrete, Semi-precast concrete board with structural rebars embedded in the bottom and two pieces of the semi-precast concrete board facing each other with their back sides facing each other with an appropriate gap and joined by welding or the like to join them together. A concrete retaining wall formwork provided with reinforcing bars and a standing means provided at the lower part of the semi-precast concrete plate to stand up the connected semi-precast concrete plate, and stood up on the waste concrete of the foundation by the standing means. Then, the structural rebar is embedded in the basic concrete poured onto the discarded concrete, and the semi-precast Doo concrete plates is characterized in that the pouring concrete.

The above-mentioned standing means has fasteners such as nuts and bolts attached to the lower portion of each of the connected semi-precast concrete plates, and the fasteners for horizontally installing the concrete retaining wall formwork by the fasteners. Is detachably attached, the surroundings of the standing uprights are surrounded by a barrier, the lower part of the semi-precast concrete plate is filled with basic concrete except for the uprights, and then the uprights are removed. It is what

The standing means is formed by fixing a standing metal fitting for horizontally installing the semi-precast concrete board under the connected semi-precast concrete boards, and embedding the standing metal fitting in the foundation concrete. The standing means may be formed as a protrusion on the lower surface of the semi-precast concrete plate, and the protrusion may be embedded in the basic concrete.

[0014]

In the method for constructing a concrete retaining wall according to claim 1 of the present invention, in a factory for producing precast concrete plates, two semi-precast concrete plates with reinforcing bars exposed on the back face are provided with a space on the back face. Provided and fastened by joining welded rebars to form a concrete retaining wall formwork, which is transported to the construction site, and then raised up on waste concrete by the standing metal fittings of the concrete retaining wall form, a structure of semi-precast concrete plate It will be embedded in the basic concrete including the reinforcing bars.

Then, concrete was poured into the gap between the two semi-precast concrete plates, and the reinforcing bars embedded in the semi-precast concrete plates and exposed at the back were buried in this concrete and poured into the semi-precast concrete plates. It is intended to be integrated with concrete.

Further, in the method for constructing a concrete retaining wall according to a second aspect of the present invention, a standing metal fitting for raising the concrete retaining wall body is provided by a fastener such as a bolt and a nut embedded in the lower portion of the semi-precast concrete plate. , Detachably attached.

After standing up of the concrete retaining wall,
The standing metal is surrounded by a barrier and the surrounding concrete is filled to maintain the standing state of the semi-precast concrete board.After that, the standing metal is removed by the cavity formed by the barrier, and the other It enables re-use in the place.

Further, in the method for constructing a concrete retaining wall according to claim 3, the semi-precast concrete plate is integrally provided with the upright metal fittings in advance so that the number of attaching the upright metal fittings on the construction site can be eliminated and the upright metal fittings can be raised. It eliminates the trouble of removing the standing metal fittings by embedding the metal fittings in the basic concrete that is poured into the concrete.

Further, in the method for constructing a concrete retaining wall according to claim 4, by providing a projecting portion on the lower surface of the semi-precast concrete plate, it is not necessary to construct the standing metal fitting separately, and the number of steps for constructing the concrete retaining wall is increased. To simplify.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the place where the retaining wall is constructed is dug down as in the conventional case, and the split A and the discarded concrete B are performed.

Also, the semi-precast concrete board 1
What is called an omnier plate is used as 1, and the reinforcing bars of this semi-precast concrete plate 11 are fixed in combination with the reinforcing bars 11a, which are fixed in combination in the vertical and horizontal directions, and are raised from the reinforcing bars 11a. The saw-toothed reinforcing bar 11b is provided, and the back reinforcing bar 11c is vertically and horizontally combined and fixed on the saw-toothed reinforcing bar 11b.

This rebar is assembled on a formwork into which concrete 15 for forming the semi-precast concrete plate 11 is poured, and the joining rebar 12 is joined to the rebar 11a in an upward direction perpendicular to the plane of the rebar 11a. Although fixed, this joint reinforcing bar 12 may be omitted when the other joint reinforcing bar is welded to the serrated reinforcing bar 11b as described later.

Further, at a predetermined position on the lower side of the semi-precast concrete plate 11 of the form when standing,
The nuts 13 are arranged in two sets on the left and right, but the mounting bolts may be embedded so that the nuts 13 project below the mold instead of the nuts 13.

A plurality of structural rebars 14 bent in a substantially right angle, that is, the semi-precast concrete plate 11 completed as a retaining wall, is required below the formwork in order to maintain strength so as not to collapse. It is fixed to the rebar 11a on the lower side such that the number of bent portions is exposed to the outside from the lower side.

Then, the concrete 15 is prevented from flowing into the screw hole of the nut 13, and the saw-toothed reinforcing bar 11b is provided.
The concrete 15 is poured onto the mold to the extent that about half of the above and the reinforcing bars 11a are buried, and the mold is removed after solidification of the mold to form the semi-precast concrete plate 11.

Therefore, the surface of the nut 13 is exposed and buried on the lower surface of the semi-precast concrete plate 11, and about half of the serrated rebars 11b and the back rebar 11c are exposed on the rear surface side. Further, the joint reinforcing bar 12 is erected on the back surface, and the structural reinforcing bar 14 is buried further below so as to expose its bent portion.

The two semi-precast concrete plates 11 formed in this way are arranged so that the exposed rear side of the serrated rebar 11b is wide so that the exposed lower side of the structural rebar 14 is wide and the opposite upper side is narrow. The two semi-precast concrete plates 11 are integrated by facing each other at predetermined intervals and welding the joining reinforcing bars 12 to each other to form a concrete retaining wall formwork. As aforementioned,
When the semi-precast concrete plate 11 is integrated by welding both ends of another joint reinforcing bar different from the joint reinforcing bar 12 to the serrated rebar 11b, it is not necessary to embed the joint reinforcing bar 12 in the semi-precast concrete 11.

The concrete retaining wall formwork is to be transported to the installation site of the concrete retaining wall. At this installation site, the upright metal fitting 16 is screwed into the nut 13 by the bolt 20 so that the lower part of the semi-precast concrete plate 11 is lowered. Attached to. However, when the mounting bolts are embedded in the semi-precast concrete plate 11, they are similarly mounted by screwing a nut.

The upright metal fitting 16 is constructed by welding a short rectangular tubular mounting portion 16b and a long rectangular tubular mounting portion 16a with their upper ends aligned and welded to each other. The mounting portion 16b and the mounting portion 16a are not joined to each other. A through hole is bored, and the bolt 20 having the head inserted through the through hole is screwed into the nut 13 to attach the mounting portion 16b to the semi-precast concrete plate 11.

In addition, the upright fitting 16 includes an installation portion 16
A female screw 17a that is screwed into the bolt leg 17 is attached to the lower end of a, and the length of the bolt leg 17 protruding from the female screw 17a can be changed by the rotation of the bolt leg 17.

In this way, the concrete retaining wall formwork of the two integrated semi-precast concrete plates 11 to which the standing metal fittings 16 are attached is formed on the waste concrete B for constructing the retaining wall, It is set up so as to form a predetermined taper. The right and left inclinations when standing up are the two left and right standing metal fittings 1.
By the bolt legs 17 of No. 6, the taper in the front-back direction is adjusted by the bolt legs 17 of any of the semi-precast concrete boards 11.

Next, a shielding wall 18 for enclosing the surroundings of the upright metal fittings 16 for erecting the respective semi-precast concrete plates 11 so as to prevent the concrete from flowing inside is disposed on the concrete B. Circulate. After that, the basic concrete C is poured onto the discarded concrete B to a height at which the lowermost part of the semi-precast concrete plate 11 is buried.

Therefore, the structural rebar 14 is embedded in the basic concrete C, and plays a role of supporting the semi-precast concrete plate 11 after removing the upright 16 and integrating the basic concrete C.

After the solidification of the basic concrete C is awaited, the shielding wall 18 is removed, and the mounting bolt 20 screwed to the nut 13 is removed, so that the upright 16 is removed from the semi-precast concrete plate 11. In this case, as described above, the semi-precast concrete plate 11 is embedded in the base concrete C at its lowermost portion and is supported by the structural reinforcing bars 14 embedded in the base concrete C. There is no fear of collapse.

Concrete 19 is poured into a hollow portion formed by the shielding wall 18 generated after the removal of the upright 16 to close the hollow, and the upright metal fitting 16 can be reused at another place by removing it. .

Further, by pouring concrete D between the front side and the back side of the semi-precast concrete plate 11, the back reinforcing bar 11c of the semi-precast concrete plate 11 and the exposed part of the serrated reinforcing bar 11b are embedded in the concrete D. However, the concrete D and the semi-precast concrete board 11 are integrated.

The construction work of the retaining wall is completed by arranging the countersunk stones on the inner surface side of the concrete retaining wall thus installed and performing a predetermined construction such as embedding soil. Therefore, since the formation of the semi-precast concrete board in the factory and the integration of the two semi-precast concrete boards are performed, the work on the construction site is reduced, the construction period is shortened, and the dimensions of the concrete retaining wall are accurate. Can be realized.

Then, as compared to the conventional precast concrete retaining wall that carried the entire concrete retaining wall,
The amount of the concrete D poured between the two semi-precast concrete plates 11 can reduce the carrying weight, and in the case of carrying the same weight, it is possible to carry a retaining wall with a long span, Combined with the fact that it can be used, construction costs can be reduced.

Next, a second embodiment of the present invention will be described below. In this embodiment, before the semi-precast concrete plate 11 in the previous embodiment is integrated by welding the joint rebar 12, the same standing metal fitting 16 as in the previous embodiment is fixedly attached to the semi-precast concrete plate 11. . And the basic concrete C that is driven in at the construction site
Since the standing metal fitting is embedded in the inside so as not to be removed, it is troublesome to attach and detach the standing metal fitting 16 at the site, to surround the surrounding wall with the shielding wall 18 and to remove it, and to embed the cavity formed thereby. Is omitted.

Further, a third embodiment of the present invention will be described below with reference to FIG. In this embodiment, the mold for pouring the concrete 15 forming the semi-precast concrete plate 11 in the previous embodiment is provided with a portion where the protrusion 21 as shown in FIG. 4 is formed, but the nut 13 is embedded. The construction of the semi-precast concrete plate 11 is the same as that of the previous embodiment except that it is not provided.

A nut 22 is preliminarily attached to the portion forming the projecting portion 21 so that concrete does not flow into the screw hole, and then concrete 15 is poured in the same way as in the previous embodiment, and the nut is placed on the lower surface. The protrusion 21 in which the nut 22 is embedded is formed.

The semi-precast concrete plates 11 thus formed are integrated by welding the two reinforcing steel bars 12 to each other with their backs facing each other at an appropriate interval as in the previous embodiment. And nut 22
The adjusting bolt 23 is screwed into the screw.

This integrated semi-precast concrete plate 11 is transported to the construction site of the concrete retaining wall in the same manner as in the previous embodiment and is erected on the concrete B to be discarded. The taper of No. 1 is performed by rotating the adjusting bolt 23, which is the same as in the previous embodiment.

In this case, the adjusting bolt 23 is attached to the protrusion 21.
Instead of screwing in, a block having an adjusting screw that can be expanded and contracted in the vertical direction may be interposed below the protruding portion 21, and the adjustment screw may be rotated to level out left and right and adjust the front and rear taper.

Then, without preventing the flow of the basic concrete C by the shielding wall 18 in the first embodiment, the projecting portion 21, the structural rebar 14, and the upright metal fitting 16 are completely buried. Since the concrete C is poured, it is possible to omit the steps of attaching and detaching the upright metal fitting 16 of the first embodiment, removing the shielding wall 18, and pouring the concrete 19 into the removal mark.

[0046]

Industrial Applicability As described above, the present invention is a method for constructing a concrete retaining wall in which front and rear surfaces of the retaining wall are formed of semi-precast concrete plates, and concrete is poured into the retaining wall to form a retaining wall. The weight of the produced semi-precast concrete board can be reduced compared to the case where the entire retaining wall is made of precast concrete at the factory.

Therefore, the transportation cost can be greatly reduced,
Alternatively, when using semi-precast concrete plates of the same weight, the width of the span of the semi-precast concrete plates can be increased, so that the width of one-time retaining wall construction will be large, and in any case the retaining wall construction cost will be low. You can

In addition, the semi-precast concrete plates forming the front and rear surfaces of the retaining wall are welded to the reinforcing bars for joining, which project from the back surface of the retaining wall, so that the two semi-precast concrete plates are integrated, and the concrete is poured between them. Even if it does, the semi-precast concrete board will not fall outside.

Since the semi-precast concrete board is made lighter, not only is it easy to stand up at a predetermined position, but also by providing an elongating means in the erecting means, the left and right are horizontally leveled and the front and rear tilts are made. Settings are easy, work can be speeded up, and the construction period can be shortened.

Furthermore, the structural rebar projecting to the bottom of the semi-precast concrete plate is used as the basic concrete that is driven onto the discarded concrete, and the rebar exposed on the back surface of the semi-precast concrete plate is the front and rear semi-precast concrete plate. Being embedded in the concrete filled in the space between them and being integrated, and further filling the space between the semi-precast concrete plates with the adjacent integrated semi-precast concrete plates Combined with what is done, it can be a strong retaining wall.

When the standing metal fittings are detachably attached to the integrated semi-precast concrete board, the cost of necessary parts can be reduced by finally removing the standing metal fittings, and the fixed metal fittings can be fixed to the semi-precast concrete board. Or when it is provided as a protrusion, it has the effect of shortening the time required for the attachment / detachment.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a main part of a first embodiment of the present invention.

FIG. 2 is a plan view of the above.

FIG. 3 is a vertical sectional view of the entire same as above.

FIG. 4 is a front view of the third embodiment of the present invention.

FIG. 5 is a vertical sectional view of an example of a conventional precast concrete retaining wall.

FIG. 6 is a plan view of the above.

FIG. 7 is a vertical cross-sectional view of another example of a conventional precast concrete retaining wall.

FIG. 8 is a plan view of the above.

[Explanation of symbols]

 B Discarded concrete C Foundation concrete D Concrete 11 Semi-precast concrete plate 11a Reinforcing bar 11b Sawtooth rebar 11c Back reinforcing bar 12 Joined reinforcing bar 13 Nut 14 Structural rebar 16 Standing metal fitting 18 Barrier wall 20 Mounting bolt 21 Protruding part 23 Adjusting bolt

Claims (4)

[Claims] 1. A semi-precast concrete plate in which a part of the reinforcing bar is exposed to the back side and is embedded in the concrete, and a structural reinforcing bar fixed in the basic concrete is embedded in the lower part, and the semi-precast concrete plate is 2
Sheets, with their rear sides facing each other through an appropriate interval, connected by welding or the like, and joined reinforcing bars that integrate them and are provided at the bottom of this semi-precast concrete plate, and the connected semi-precast concrete plate is connected. A concrete retaining wall formwork having an erecting means for erecting, erecting on the waste concrete of the foundation by the erecting means,
A method for constructing a concrete retaining wall characterized by burying structural reinforcing bars in basic concrete poured onto discarded concrete, and pouring concrete between semi-precast concrete plates. 2. The erection means has fasteners such as nuts and bolts attached to the lower portion of each of the connected semi-precast concrete plates, and the fasteners are used to horizontally install the concrete retaining wall formwork. The standing metal fittings are detachably attached, the surroundings of the standing metal fittings are surrounded by a barrier, and the lower part of the semi-precast concrete plate is filled with basic concrete excluding the portion of the standing metal fittings, and then the standing metal fittings are removed. The method for constructing a concrete retaining wall according to claim 1, wherein: 3. The standing means is formed by fixing a standing metal fitting for horizontally installing the semi-precast concrete board to the lower part of the connected semi-precast concrete boards, and embedding the standing metal fitting in the foundation concrete. The method for constructing a concrete retaining wall according to claim 1, wherein 4. The construction of a concrete retaining wall according to claim 3, wherein the standing means is formed as a projecting portion on the lower surface of the semi-precast concrete plate, and the projecting portion is embedded in the basic concrete. Method.