JP2022047737A - Construction method of retaining wall - Google Patents

Abstract

To provide a construction method of a retaining wall with high construction efficiency allowing a wall panel to be securely supported with simple means with less welding operation on a rear side of the wall panel.SOLUTION: A construction method of a retaining wall of the present invention includes base construction step S1, base joint step S2, joint rod fixing step S3, installation step S4, panel erection step S5, and joint rod extension step S6. The installation step S4, the panel erection step S5, and the joint rod extension step S6 are repeated, and successively the installation S4 is performed after the panel erection step S5 of an uppermost stage. A slope of a wall panel 20 of an upper stage is made to correspond to a slope of the wall panel 20 of a lower stage by placing a rear panel of a panel body 21 of the wall panel 20 of the upper stage along a joint rod 40 of the lower stage in the panel erection step S5.SELECTED DRAWING: Figure 5C

Description

The present invention relates to a method for constructing a retaining wall, and more particularly to a method for constructing a retaining wall with high construction efficiency, which requires less welding work on the back side of the wall panel and can reliably support the wall panel by simple means.

A half precast retaining wall is known, which is constructed by stacking precast wall panels on the front side of the construction surface and placing interstitial concrete on the back of the wall panels.
Patent Document 1 discloses a half precast retaining wall characterized in that a mesh holder and a water-permeable sheet material are arranged in combination in the construction of a backing material. In this half precast retaining wall, anchor bars are embedded in each stage of foundation concrete and interstitial concrete, and connecting reinforcing bars are laid between the anchor bars and the back surface of the wall panel for each stack of wall panels. The wall panel is supported on the construction surface by mutually welding the reinforcing bar and the back reinforcing bar of the wall panel.

Japanese Unexamined Patent Publication No. 2020-12310

The prior art has the following problems.
<1> Since it is necessary to install anchor bars on the interstitial concrete and weld the wall panels and anchor bars each time the wall panels are stacked, there are many processes and the construction efficiency is poor.
<2> Welding of anchor bars and connecting reinforcing bars in a narrow space on the back side of the wall panel is complicated and difficult to construct. In particular, it is difficult to weld to the anchor bar while maintaining the slope of the wall panel at the design slope.
<3> Since welding cannot be performed in rainy weather, construction depends on the weather.

An object of the present invention is to provide a method for constructing a retaining wall that can solve the above problems.

A method of constructing a retaining wall of the present invention is to use a wall panel comprising a panel body and a back surface reinforcing bar extending along the width direction of the panel body while being separated from the back surface of the panel body, from a slope or a straight wall. A half-precast wall is constructed on the front of the construction surface, which is a method of constructing the wall. A long connecting rod is inserted and fixed between the back surface and the back reinforcing bar of the panel body and the foundation connecting process of installing and connecting the wall panel to the foundation concrete, and the upper part of the connecting rod is above the wall panel. The wall panel on the upper stage is erected on the wall panel, and the step of fixing the connecting rod, and the step of placing and hardening the interstitial concrete between the back surface of the wall panel and the construction surface. Then, the panel erection process of inserting the connecting rod between the back surface of the panel body of the upper wall panel and the back reinforcing bar, and the connecting rod of the upper stage between the back surface of the panel body of the upper wall panel and the back reinforcing bar. It is equipped with a connecting rod extension step of inserting and fixing and projecting the upper part of the upper connecting rod upward from the upper wall panel, and includes a casting process, a panel standing process, and a connecting rod extension step. Repeatedly, the casting process is performed following the uppermost panel erection process, and in the panel erection process, the back surface of the panel body of the upper wall panel is placed along the lower connecting rod to form the upper wall panel. It is characterized in that the slope corresponds to the slope of the lower wall panel.

In the method of constructing the retaining wall of the present invention, in the connecting rod fixing step and the connecting rod extension step, the connecting rod is pressed and fixed to the back surface of the panel body by inserting a wedge material between the connecting rod and the back surface reinforcing bar. You may.

In the method for constructing a retaining wall of the present invention, the connecting rod is composed of a long face material having two side edges on the short side and two sides on the long side, and is used in the connecting rod fixing step and the connecting rod extending step. , The side edge of the connecting rod may be brought into contact with the back surface of the panel body and fixed.

In the method of constructing the retaining wall of the present invention, in the connecting rod extension step, the side surface of the upper connecting rod is brought into contact with the side surface of the lower connecting rod, and the two connecting rods are sandwiched between the holding tools. You may connect the connecting rods of.

In the method of constructing the retaining wall of the present invention, the foundation concrete is provided with an anchor bar partially protruding on the upper part of the foundation concrete, and in the foundation connecting step, the back reinforcing bar of the wall panel and the anchor reinforcing bar are connected by the connecting reinforcing bar. The back surface reinforcing bars, connecting reinforcing bars, and anchor reinforcing bars may be welded and fixed to each other.

The method for constructing a retaining wall of the present invention has at least one of the following effects.
<1> Since the wall panel can be reliably supported by simply extending the connecting rod upward while fixing the connecting rod to the back surface of the wall panel, the number of man-hours is small and the construction efficiency is high.
<2> Since there is no welding work on the back side of the wall panel, it is easy to install and can be installed even in a narrow site.
<3> By simply stacking the wall panels along the connecting rod, the slopes of the upper and lower wall panels can be autonomously matched. Therefore, the construction is easy and the construction accuracy is high.
<4> Since there is no welding work after the connection with the foundation, it can be constructed regardless of the weather.

Explanatory drawing of the basic connection process. Explanatory drawing of connecting rod fixing process. Explanatory drawing of connecting rod fixing process. Explanatory drawing of the placing process. Explanatory drawing of panel erection process. Explanatory drawing of connecting rod extension process. Explanatory drawing of connecting rod extension process. Explanatory drawing of connecting rod extension process. Explanatory drawing of panel erection process (third stage).

Hereinafter, the method of constructing the retaining wall of the present invention will be described in detail with reference to the drawings.

[Retaining wall construction method]
<1> Overall configuration.
The method of constructing a retaining wall of the present invention is a method of constructing a half precast retaining wall on the front surface of a construction surface composed of a slope or a straight wall.
In this example, the case where the construction surface is a slope is illustrated, but the same procedure can be applied to a straight wall.
The method of constructing the retaining wall of the present invention includes at least a foundation construction step S1, a foundation connecting step S2, a connecting rod fixing step S3, a placing step S4, a panel erection process S5, and a connecting rod extension step S6. Be prepared.

<1.1> Wall panel (Fig. 2B).
The wall panel 20 is a face material that constitutes the wall surface of the retaining wall 1 in parallel in the vertical and horizontal directions.
The wall surface panel 20 is a precast concrete panel including at least a panel main body 21 made of a concrete plate having a rectangular front view and a back reinforcing bar 22 extending to the back side of the panel main body 21.
In this example, the back surface reinforcing bar 22 is composed of a combination of a plurality of truss bars 22a formed by partially projecting the reinforcing bars in the panel body 21 toward the back surface and a linear fixing bar 22b welded to the plurality of truss bars 22a. Adopt an integrated structure.
Specifically, from the back surface of the panel body 21, a plurality of truss bars 22a are arranged in four rows above and below along the width direction of the panel body 21, and two fixing bars 22b are arranged along the width direction of the panel body 21. Then, each fixing bar 22b is welded and fixed to the tips of the truss bars 22a in the upper and lower rows.
However, the configuration of the back surface reinforcing bar 22 is not limited to this, for example, a truss bar 22a is not provided, a part of the reinforcing bar in the panel body 21 is exposed on the back surface side of the panel body 21, and extends along the width direction of the panel body 21. The back surface reinforcing bar 22 may be configured by being present.
In short, the rear reinforcing bar 22 may be integrated with the panel main body 21 and may extend along the width direction of the panel main body 21 while being separated from the back surface of the panel main body 21.

<2> Foundation construction process.
The foundation construction step S1 is a step of installing the foundation concrete 10.
In detail, the foundation construction step S1 is carried out by, for example, the following procedure.
The ground in front of the construction surface is excavated to a predetermined depth over the construction area.
Spread the foundation crushed stone on the excavated surface and roll it with a rammer or the like. The foundation concrete 10 is placed on the foundation crushed stone.
In this example, anchor bars 31 for supporting the wall surface panel 20 are embedded in the foundation concrete 10 at predetermined intervals, and the upper part of the anchor bars 31 is projected from the upper part of the foundation concrete 10. For the anchor bar 31, for example, a reinforcing bar bent in an inverted V shape can be used.
After placing, the foundation concrete 10 is cured for a predetermined time.

<3> Basic connection process (Fig. 1).
The foundation connecting step S2 is a step of erection of the first-stage wall panel 20 on the foundation concrete 10 and connecting to the foundation concrete 10.
In detail, the foundation connecting step S2 is carried out by, for example, the following procedure.
The wall panel 20 is hung on the foundation concrete 10, and the front surface of the wall panel 20 is tilted to a design slope corresponding to the slope of the construction surface.
At the same time, the anchor bar 31 installed on the foundation concrete 10 and the fixing bar 22b of the wall panel 20 are connected by a connecting reinforcing bar 32, and the anchor bar 31 and the connecting reinforcing bar 32 and the connecting reinforcing bar 32 and the fixing bar 22b are contacted with each other. Weld with and fix each other.
The welding destination of the connecting reinforcing bar 32 may be a truss bar 22a instead of the fixed bar 22b. Further, other known support members may be used. In short, it suffices if the first-stage wall panel 20 can be securely connected to the foundation concrete 10.
As described above, the first-stage wall panel 20 is securely connected to the foundation concrete 10 via the foundation connecting material 30 (anchor bar 31 and connecting reinforcing bar 32).
In the method of constructing the retaining wall of the present invention, the welding work is limited to the foundation connecting step S2 and is not performed in other steps, so that the workability and the safety of the work are high.

<4> Connecting rod fixing step (FIG. 2A).
The connecting rod fixing step S3 is a step of fixing the connecting rod 40 to the back surface of the first-stage wall panel 20.
The connecting rod 40 is a member having both a supporting function of supporting the wall surface panel 20 and a function of a ruler material for matching the gradients of the upper and lower wall surface panels 20 until the subsequent placing step S4.
In this example, as the connecting rod 40, a steel flat bar (flat steel) having two side edges 40a on the short side and two side surfaces 40b on the long side is adopted.
The flat bar used has a length longer than the height of the wall surface panel 20 and a width between the two side edges 40a smaller than the distance between the back surface of the panel main body 21 and the fixing bar 22b.
The connecting rod 40 is not limited to the flat bar, but may be a circular steel rod, a square steel rod, or the like.
In detail, the connecting rod fixing step S3 is carried out by, for example, the following procedure.

<4.1> Insertion of connecting rod.
The connecting rod 40 is inserted between the back surface of the panel main body 21 of the first-stage wall panel 20 and the upper and lower fixing bars 22b. The upper portion of the connecting rod 40 is projected above the upper edge of the wall surface panel 20.
In this example, the flat bar of the connecting rod 40 is brought into vertical contact with the back surface of the panel main body 21. In other words, the side edge 40a of the flat bar is brought into contact with the back surface of the panel body 21.
As a result, refraction of the connecting rod 40 due to the load of the wall surface panel 20 can be prevented, and the wall surface panel 20 can be stably supported.
In this example, the number of connecting rods 40 is 2 for each wall panel 20. However, the present invention is not limited to this, and for example, one wall panel 20 may have three or more.

<4.2> Fixation with wedge material (Fig. 2B).
The wedge material 50 is inserted from above between the side edge 40a of the connecting rod 40 and the fixing bar 22b.
Subsequently, by hitting the head of the wedge material 50 with a hammer or the like, the connecting rod 40 is sandwiched between the back surface of the panel main body 21 and the fixing bar 22b in the front-rear direction and fixed.
The same operation is performed at all the intersections of the connecting rod 40 and the fixing bar 22b.
In this example, by combining the wedge material 50 with the connecting rod 40, the side edge 40a of the connecting rod 40 can be pressed against the back surface of the panel main body 21 so that the gradient of the connecting rod 40 matches the gradient of the wall surface panel 20. ..
The connecting rod 40 is not limited to the space between the back surface of the panel body 21 and the fixing bar 22b, and may be sandwiched and fixed between the back surface of the panel body 21 and the truss bar 22a, for example.
Further, when the clearance between the panel main body 21 and the fixing bar 22b and the width of the connecting rod 40 is small, the wedge material 50 may not be used.

<5> Casting process (Fig. 3).
The placing step S4 is a step of placing the interstitial concrete 60 on the back surface side of the wall surface panel 20.
In detail, the placing step S4 is carried out by, for example, the following procedure.
The interstitial concrete 60 is placed between the back surface of the wall surface panel 20 and the construction surface to a height several cm below the upper edge of the wall surface panel 20. This is because the seam of the wall panel 20 and the seam of the interstitial concrete 60 do not overlap.
After placing, the interstitial concrete 60 is cured for a predetermined time.
By hardening the interstitial concrete 60, the connecting rod 40 fixed to the back surface of the wall surface panel 20 is integrated with the interstitial concrete 60 and the back surface reinforcing bar 22, and has stability capable of supporting the second stage wall panel 20.
In this example, the interstitial concrete 60 is placed directly on the construction surface on the back surface of the wall panel 20, but in actual construction, a backing material may be installed along the construction surface or similar to the wall panel 20. The back panel of the structure can be arranged. However, since these configurations are not the main points of the present invention, the description thereof will be omitted.

<6> Panel erection process (Fig. 4).
The panel erection step S5 is a step of erection of the upper wall panel 20 on the upper part of the lower wall panel 20.
The panel erection step S5 is carried out in detail, for example, by the following procedure.
The second-stage wall panel 20 is hung from the upper part of the first-stage wall panel 20 by using a heavy machine or the like. At this time, the worker can work on the first-stage packed concrete 60 as a scaffold.
At the time of hanging, the upper part of the connecting rod 40 fixed to the first-stage wall panel 20 is inserted into the gap between the back surface of the panel main body 21 of the second-stage wall panel 20 and the upper and lower two rows of fixing bars 22b.
After hanging, the wall surface panel 20 is leaned against the connecting rod 40, and the back surface of the panel main body 21 is brought into contact with the side edge 40a of the connecting rod 40.

<7> Connection rod extension step (FIG. 5A).
The connecting rod extension step S6 is a step of connecting the upper connecting rod 40 to the upper part of the lower connecting rod 40.
The connecting rod extension step S6 is carried out in detail, for example, by the following procedure.

<7.1> Connection of two connecting rods (FIG. 5B).
A second-stage connecting rod 40 is inserted between the back surface of the second-stage panel main body 21 and the fixing bar 22b, and the upper portion is projected above the second-stage wall panel 20.
Subsequently, the side surface of the second-stage connecting rod 40 is brought into contact with the side surface of the first-stage connecting rod 40, and the longitudinal direction of the second-stage connecting rod 40 is along the longitudinal direction of the first-stage connecting rod 40. In the state of being brought together, the two connecting rods 40 are sandwiched from the side surface 40b by the holding tool 70 and connected.
In this example, a double clip for office use is adopted as the holding tool 70.
Here, the connection by the holding tool 70 is merely a temporary fixing prior to the fixing by the wedge material 50 described later, and the holding tool 70 alone does not support the upper wall panel 20. Therefore, the connection of the connecting rod 40 can be easily performed by using a simple holding tool 70 such as a double clip for office work.
The clipper 70 is not limited to the double clip, but may be an eyeball clip, a chevron clip, a resin binding band, or the like. Further, instead of using the holding tool 70, for example, a flat bar having a long hole bolt hole is adopted as the connecting rod 40, and bolts are inserted and fastened through the bolt holes of the two connecting rods 40 that are in contact with each other. May be good.

<7.2> Fixing with wedge material (Fig. 5C).
The wedge material 50 is inserted from above between the side edges 40a of the two temporarily fixed connecting rods 40 and the fixing bar 22b, and the head of the wedge material 50 is hit with a hammer to attach the connecting rod 40. It is fixed by being sandwiched between the back surface of the panel body 21 and the fixing bar 22b in the front-rear direction.
The same operation is performed at all the intersections of the connecting rod 40 and the fixing bar 22b.
As a result, the first-stage wall panel 20 is securely connected to the second-stage wall panel 20 via the connecting rod 40, and the two connecting rods 40 are integrally fixed.
Further, since the first-stage connecting rod 40 is in contact with the back surface of the first-stage panel main body 21, the back surface of the second-stage panel main body 21 is brought into contact with the side edge 40a of the connecting rod 40. This makes it possible to match the gradient of the second-stage wall panel 20 with the gradient of the first-stage wall panel 20.

<8> Repeat the process.
After that, as in the second-stage casting process, the third-stage panel erection process (FIG. 6), the third-stage connecting rod extension process, and so on, the casting process up to a predetermined number of stages of the wall surface panel 20. S4, the panel erection step S5, and the connecting rod extension step S6 are repeated.
However, since it is not necessary to extend the connecting rod 40 above the uppermost stage, the placing step S4 is performed after the uppermost panel erecting step S5 to complete the construction.

1 Retaining wall 10 Foundation concrete 20 Wall panel 21 Panel body 22 Back reinforcement 22a Truss reinforcement 22b Fixing reinforcement 30 Foundation connecting material 31 Anchor reinforcement 32 Connecting reinforcing bar 40 Connecting rod (flat bar)
40a Side edge 40b Side 50 Wedge material 60 Stuffed concrete 70 Clipper (double clip)

Claims (5)

Half precast to the front of a construction surface consisting of a slope or straight wall using a wall panel comprising a panel body and a back reinforcing bar extending along the width direction of the panel body while being separated from the back of the panel body. It is a method of constructing a retaining wall, which is a method of constructing a retaining wall.
The foundation construction process, in which the foundation concrete is installed on the ground in front of the construction surface,
A foundation connecting step in which the wall panel is erected on the foundation concrete and the wall panel is connected to the foundation concrete.
A connecting rod fixing step in which a long connecting rod is inserted and fixed between the back surface of the panel body and the back surface reinforcing bar, and the upper portion of the connecting rod is projected upward from the wall surface panel.
A casting process in which interstitial concrete is cast and hardened between the back surface of the wall panel and the construction surface.
A panel erection process in which an upper wall panel is erected on the wall panel and the connecting rod is inserted between the back surface of the panel main body of the upper wall panel and the back reinforcing bar.
A connecting rod in which the upper connecting rod is inserted and fixed between the back surface of the panel main body of the upper wall panel and the back reinforcing bar, and the upper portion of the upper connecting rod is projected upward from the upper wall panel. With an extension process,
The placing step, the panel erection step, and the connecting rod extension step are repeated, and the placing step is performed following the panel erection step at the uppermost stage.
In the panel erection step, the back surface of the panel main body of the upper wall panel is aligned with the connecting rod in the lower stage so that the slope of the upper wall panel corresponds to the slope of the lower wall panel. Features,
Retaining wall construction method. In the connecting rod fixing step and the connecting rod extending step, the connecting rod is pressed and fixed to the back surface of the panel body by inserting a wedge material between the connecting rod and the back surface reinforcing bar. The method for constructing a retaining wall according to claim 1. The connecting rod is composed of a long face material having two side edges on the short side and two sides on the long side, and is attached to the back surface of the panel body in the connecting rod fixing step and the connecting rod extending step. The method for constructing a retaining wall according to claim 2, wherein the side edges of the connecting rod are brought into contact with each other and fixed. In the connecting rod extension step, the side surface of the upper connecting rod is brought into contact with the side surface of the lower connecting rod, and the two connecting rods are sandwiched between the holding tools to connect the two connecting rods. The method for constructing a retaining wall according to claim 3, wherein the retaining wall is constructed. The foundation concrete is provided with an anchor bar partially protruding from the upper part of the foundation concrete, and in the foundation connecting step, the back surface reinforcing bar of the wall surface panel and the anchor reinforcing bar are connected by a connecting reinforcing bar, and the back surface reinforcing bar, the said. The method for constructing a retaining wall according to any one of claims 1 to 4, wherein the connecting reinforcing bars and the anchor reinforcing bars are welded to each other and fixed to each other.

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