KR20100115919A - Retaining wall and construction method thereof - Google Patents

Abstract

PURPOSE: A retaining wall and a construction method thereof are provided to prevent the activity or the conduction of a retaining wall and to prevent interference with a surrounding construction structure. CONSTITUTION: A retaining wall comprises a wall body(10), a shelf(20), and a soil nail(30). The wall stands up on the side of a cut ground(1). The shelf is installed on the rear side of the wall and is buried under the ground. The soil nail connects the wall to the ground. The wall and the shelf are composed of a reinforcing bar concrete structure. The soil nails are installed on the lower wall based on the shelf.

Description

Retaining wall and construction method

The present invention relates to a retaining wall and a construction method thereof, and to a retaining wall and a construction method of which a nail and a shelf are installed to greatly improve stability and workability.

Retaining wall is a wall structure that prevents the collapse of soil by supporting the fill or cut slope by resisting soil pressure. It is widely used in mountain areas and both side walls of roads.

As the development progresses, the density of urban buildings increases, and the distance between the building structures and the retaining walls and the distance between the retaining walls and the site boundary gradually decrease according to the tendency to maximize the land utilization.

Therefore, a conventional reinforced concrete retaining wall (RC retaining wall) or anchor retaining wall has been more difficult to install because the bottom plate or anchor of the retaining wall interferes with adjacent building structures and crosses the site boundary.

In addition, the general cantilever style retaining wall has a disadvantage in that the excavated soil is greatly increased because a sufficient trench area is required for the bottom plate construction, and this problem is aggravated as the height difference of the retaining wall installation position increases.

In addition, when the height of the retaining wall is high, the earth pressure is large, so the length of the bottom plate must be long in order to resist the earth pressure, and when the permanent anchor is installed, the thickness of the retaining wall is increased.

Therefore, the distance between the building structure and the site boundary is small, the height difference is big, the excavation volume is excessive, so that the existing retaining wall construction is difficult to be installed more easily, and the economic and stability retaining wall and its construction method are excellent. Was needed.

Accordingly, the present invention has been devised in response to the above-described demands, and less likely to interfere with neighboring building structures or invade neighboring site boundaries, reduce excavation soil, facilitate construction, and reduce air and required costs. The purpose is to provide a retaining wall and its construction method that can be more reliably prevented in the activity or fall of the retaining wall.

Retaining wall according to the present invention for achieving the above object,

A wall erected on the side of the cut ground;

A shelf installed on the rear surface of the wall and embedded in the ground;

A nail nail connecting the wall with the ground;

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The wall and the shelf are made of a single reinforced concrete structure.

The small nails are installed on the lower wall on the basis of the shelf.

The lower wall of the wall based on the shelf is made of an inner shotcrete layer and an outer concrete layer, a wire mesh to the shotcrete layer, connecting reinforcing bars fixed to the wire mesh, and a pressure plate mounted on the small nail And the nut which fixes the pressure plate is buried.

In addition, an end portion of the small nail is embedded in the concrete layer.

In addition, a stud is mounted on the pressure plate, and the stud is embedded in the concrete layer.

At the end of the stud is formed a radially extending head of the body.

The stud is fixed to the rebar of the concrete layer.

On the other hand, the retaining wall construction method according to the present invention for constructing the retaining wall,

A small nailing step of inserting a small nail into the cut ground and placing a shotcrete layer;

A lower wall construction step of constructing a lower wall connected to the small nail by pouring a concrete layer on the outside of the shotcrete layer;

A shelf mounting surface forming step of providing a shelf mounting surface at the same height as the upper end of the lower wall;

A shelf and an upper wall construction step of constructing a shelf and an upper wall integrally with the lower wall on the shelf mounting surface;

A back filling step of filling the rear spaces of the upper and upper walls of the shelf;

It includes.

In the small nailing step, the stud is further mounted on the pressure plate mounted on the small nail, and then the lower wall construction step is performed.

The small nailing step may include inserting a plurality of small nails into the ground and sequentially inserting the upper and lower portions of the ground.

In the lower wall construction step, the reinforcing bar that is installed inside the lower wall is extended and installed outside the upper end of the lower wall, and then, in the shelf and upper wall construction step, the reinforcing bar of the shelf and the upper wall is connected to the reinforcing bar of the lower wall. I'm going to work out.

The shelf and the upper wall construction step is to cast concrete on the integrally formed formwork.

The present invention as described above,

Due to the interaction between the shelf and the nail, the retaining ground support strength of the retaining wall and the stability of the activity and the conduction are doubled, thereby reducing the thickness of the retaining wall and eliminating the need to construct the bottom plate.

Therefore, the time and cost required for earthworks are greatly reduced by eliminating the process of digging for the low plate construction, and the construction can be more easily performed.

In addition, since there is no bottom plate and a small nail is used, there is less concern about interference with neighboring building structures and invasion of neighboring site boundaries, and thus construction can be easily performed in areas with high density of building structures.

In addition, since the initial nailing step is performed in a top-down manner in the middle portion of the slope, the retaining wall installation location can be easily installed in an area where the lower part is cut and the upper part needs to be filled.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 (a) is an installation state diagram of a retaining wall according to the present invention, and (b) is an installation state diagram of a retaining wall provided with a bottom plate as a comparative example of the above (a).

2 (a) is a state of earth pressure action of the retaining wall according to the present invention, and (b) is a state of earth pressure action of the retaining wall provided with a bottom plate as a comparative example of (a).

As shown in Figure 1 (a), the retaining wall according to the present invention is a wall (10) erected on the side of the cut ground (1), and the shelf provided on the back surface (the ground (side side) side) of the wall (10) And a small nail 30 for connecting the lower portion of the shelf 20 of the wall 10 to the ground 1 (hereinafter, the lower portion of the shelf 20 of the wall 10). The lower wall 10a and the upper portion of the shelf 20 are referred to as the upper wall 10b.)

The wall 10 may be installed in a state perpendicular to the ground 2 or inclined at an angle toward the ground 1, and the shelf 20 may be installed horizontally with respect to the ground 2. It is embedded in the ground (1).

The shelf 20 is integrally and firmly installed on the wall 10 so as to stably support the load.

To this end, the wall 10 and the shelf 20 is preferably integrated as a reinforced concrete structure.

The small nail 30 mainly uses a deformed reinforcing bar (release bar), the majority of the body is inserted into the ground (1) is subjected to earth pressure, one end is buried in the interior of the lower wall (10a) and connected integrally do.

In addition, the small nail 30 is installed in a plurality of spaced apart from each other at regular intervals in the vertical direction and the left and right directions throughout the lower wall (10a).

Therefore, in the retaining wall according to the present invention, the load of the upper ground 1 is prevented from being transmitted downward by the shelf 20 so that the earth pressure acting on the lower wall 10a is primarily reduced, and in addition, the thumbnail (30) increases the shear strength of the ground 1, that is, the ground itself, further reducing the earth pressure acting on the lower wall 10a. (P3 > P1 + P2; P1 = acting on the lower wall 10a) To earth pressure, P2 = earth pressure acting on the upper wall (10b), P3 = earth pressure acting on the entire wall (10) without the shelf (20), see Figure 2)

Therefore, the retaining wall according to the present invention has a sufficient degree of support force and retaining wall of the ground 1 without constructing the bottom plate 5 or increasing the thickness of the wall 10 as in the comparative example of FIG. You will be able to secure stability in activities and evangelism.

Therefore, the construction of the retaining wall according to the present invention does not require the excavation process for the construction of the bottom plate 5, so the excavated soil is greatly reduced, thereby greatly reducing the time and cost required for earthwork, and facilitates the construction. .

In addition, the retaining wall according to the present invention can be installed in close proximity to the site boundary because the bottom plate 5 does not exist so that it is not necessary to consider the interference problem of the underground building structure adjacent to the bottom plate 5. Therefore, it is advantageous to install in places where the distance between the building structure and the site boundary is short.

In addition, the small nail 30 has a shorter length than that of the permanent anchor, so it is less likely to break into the neighboring site beyond the site boundary, and thus, the small nail 30 is advantageously installed in a place having a short separation distance between the retaining wall and the site boundary.

In other words, it is more usable in the present time when the construction structure is becoming dense as development progresses.

In addition, even if the height difference between the upper surface of the ground (1) and the lower surface of the lower surface (2) is large, the retaining wall according to the present invention does not need to construct a long bottom plate (5), so there is no need to worry about excessive increase in the earthwork volume. It can be easily constructed.

Meanwhile, as shown in FIG. 3, the lower wall 10a includes a shotcrete layer 11 in contact with the ground 1 and a concrete layer 12 in contact with the shotcrete layer 11.

The inside of the shotcrete layer 11 is provided with a wire mesh 11a and a connecting reinforcing bar 11b tied thereto to reinforce the strength.

In addition, the inside of the concrete layer 12 is reinforced horizontally and vertically reinforced reinforcement (12a) to form a reinforced concrete structure by combining with the concrete to be poured later.

A pressure plate 31, which is a rectangular plate, is disposed on the outside of the connecting reinforcing bar 11b, and the hemispherical nut 33 is fastened to the small nail 30 penetrating the pressure plate 31 through the liner screw 32. And the pressure plate 31 is fixed to the small nail 30 in a state where the pressure plate 31 is pressed toward the wire mesh 11a.

The pressure plate 31 and the nut 33 are also embedded in the shotcrete layer 11.

In addition, an end portion of the nail nail 30 protruding to the outside of the nut 33 is embedded in the concrete layer 12 to reinforce the coupling force between the small nail 30 and the lower wall 10a.

In addition, a stud (34) is mounted to the pressure plate (31), the stud (34) has a head (34a) extending in the radial direction of the body at one end.

A male screw is formed at the other end of the stud 34 so as to be screwed into a tap hole formed in the pressure plate 31 or have a simple cylindrical shape in which the male screw is not formed, and is welded to the pressure plate 31.

The stud 34 is embedded in the concrete layer 12, and the majority of the body of the stud 34 is located in the concrete layer 12 such that the head 34a of the stud 34 is located outside the reinforcing bar 12a. (Part of the pressure plate 31 side is located in the shotcrete layer 11), and the head 34a has a shape protruding radially with respect to the longitudinal direction of the stud 34 so that the concrete layer ( 12) more firmly combined.

In addition, the stud 34 may be fixed to the reinforcing bar (12a) by binding to a wire or the like. Therefore, the bonding force with the concrete layer 12 can be further reinforced, and the installation position can be firmly maintained against the placing pressure when placing concrete.

On the other hand, the reinforcing bar (12a) is extended and protruded to the upper portion of the lower wall (10a) is inserted into the shelf 20 and the upper wall (10b) is connected to.

That is, the reinforcing bar 12a protruding to the upper part of the lower wall 10a in order to construct the shelf 20 and the upper wall 10b integrally with the lower wall 10a as described above is also a reinforced concrete structure. It is connected to the reinforcing steel bars that are placed in the interior of the shelf 20 and the upper wall 10b, and embedded in the concrete forming the shelf 20 and the upper wall 10b.

Now, the construction method of the retaining wall will be described with reference to FIGS. 4 to 17.

In the retaining wall construction method according to the present invention, as shown in the block diagram of FIG. 4, a small nailing step of installing a plurality of small nails 30 on the cut ground 1 and forming the shotcrete layer 11 covering the slopes (S1) ) And a lower wall construction step (S2) of forming the concrete layer 12 on the outside of the shotcrete layer 11 to construct the lower wall 10a connected to the small nail 30, and the lower wall 10a. Shelf mounting surface forming step (S3) to provide a shelf mounting surface at the same height as the top of the shelf, the shelf 20 and the shelf to construct the upper wall (10b) integrally with the lower wall (10a) on the shelf mounting surface and The upper wall construction step (S4), and the back filling step (S5) of filling the rear space of the upper and upper wall (10b) of the shelf (20).

As shown in FIGS. 5 to 11, the small nailing step S1 is sequentially performed in a TOP-DOWN manner.

Fig. 5 schematically shows the place where the retaining wall is to be installed, where 1 is cut ground and 2 is ground.

First, as shown in FIG. 6, a one-stage small nail 30a is installed at a middle portion of the slope of the ground 1, that is, the position at which the shelf 20 is to be installed. In this way, after the uppermost single-stage short nail 30a is installed, it is further excavated downward as shown in FIG. 7, and then, the second-stage small nail 30b is installed.

Subsequently, the three-stage, four-stage, and five-stage small nails 30c, 30d, and 30e are repeatedly installed in the same manner until the installation position is adjacent to the ground 2, as shown in FIGS. An example of installing up to five stages of nails is shown, but the number of stages is increased or decreased according to the retaining wall design.)

On the other hand, in the small nailing step (S1), shotcrete pouring is performed every time the small nails of each stage are installed.

The small nailing process will be briefly described as follows. (See FIG. 3 for a detailed configuration.) First, the surface of the ground 1 is arranged, and then primary shotcrete is placed on a vertical surface. Then, the drilling operation is carried out, the nail nail 30 is inserted into the hole and the first grouting is performed.

The wire mesh 11a and the connecting reinforcing bar 11b are installed on the primary shotcrete layer formed as described above, and the pressure plate 31 is provided on the end side of the small nail 30.

Subsequently, when the second shotcrete is poured and the second grouting is performed using a pre-planted grouting tube, one stage of nailing is finished.

Thereafter, the excavation and surface finishing process is repeated for the next stage of nailing.

As described above, the first and second shotcrete pouring is performed every time the nails of each stage are installed, so that the shotcrete layer 11 is constructed on the ground 1 as shown in FIG. It becomes.

On the other hand, a plurality of studs 34 may be installed on the pressure plate 31 in order to further secure the coupling state between the small nail 30 and the lower wall 10a. As described with reference to FIG. 3, the stud 34 may be screwed or welded to the pressure plate 31, and a disk-shaped head 34a is formed at an end thereof.

Therefore, the nut 33 for fixing the wire mesh 11a, the connecting reinforcing bar 11b, the pressure plate 31, and the pressure plate 31 when the small nailing step S1 is completed is made of the shotcrete layer 11. Buried in the interior, the end of the nail nail 30 and the stud 34 is protruded to the outside of the shotcrete layer (11).

In the lower wall construction step (S2), as shown in FIG. 12, the reinforcing bar 12a is disposed outside the shotcrete layer 11 and a formwork 13 is installed. At this time, the reinforcing bar (12a) is extended to the upper portion of the formwork 13 to connect the lower wall (10a) and the shelf 20 and the upper wall (10b).

Subsequently, as shown in FIG. 13, concrete is poured into the formwork 13 to construct the lower wall 10a. At this time, as the formwork 13 can be provided with a pattern formwork having a predetermined pattern on the inner surface, in this case it can give aesthetics to the appearance of the retaining wall.

After the construction of the lower wall (10a) as described above, as shown in Figure 14, the shelf mounting surface forming step (S3) is carried out.

In the shelving mounting surface forming step (S3) is excavated and stopped to the inside of the ground (1) at the same height as the upper end of the lower wall (10a) to form a flat shelving mounting surface (3).

Subsequently, the shelf and the upper wall construction step S4 are performed as shown in FIG. 15.

The reinforcing bars 20a and 12b of the shelf 20 and the upper wall 10b are integrally disposed on the upper end surface of the lower wall 10a and the shelving mounting surface 3, and the formwork 21 and 14 thereof. Also install integrally.

At this time, the reinforcing bar 12a of the lower wall 10a protruding to the upper surface of the lower wall 10a is introduced into the molds 21 and 14, and the shelf 20 and the upper wall 10b. Is connected to the reinforcing bars 20a and 12b.

After the molds 21 and 14 are installed, concrete is poured and cured into the molds 21 and 14 at the same time, thereby constructing the shelf 20 and the upper wall 10b.

When the shelf 20 and the upper wall 10b is hardened to a predetermined strength or more, the molds 21 and 14 are removed, and finally, the back filling step S5 is performed as shown in FIG. 17.

That is, the soil is filled and compacted in the rear space of the upper and upper walls 10b of the shelf 20.

By carrying out the above steps (S1 ~ S5) it is possible to construct the retaining wall according to the invention the wall 10 is connected to the small nail 30 and the shelf 20 on the back.

On the other hand, the retaining wall construction method according to the present invention is carried out in a top-down manner in which the small nailing step (S1) proceeds from the top to the bottom, and backfilling the rear space of the shelf 20 and the upper wall (10b) Since the retaining wall installation position is based on the retaining wall, it can be very advantageously applied to a mountainous area where the upper part is to be filled and the lower part is to be cut.

(A) is an installation state diagram of the retaining wall according to the present invention, (b) is an installation state diagram of the retaining wall provided with a bottom plate as a comparative example of (a),

(A) is a earth pressure action state diagram of the retaining wall according to the present invention, (b) is a earth pressure action state diagram of the retaining wall provided with a bottom plate as a comparative example of (a),

3 is a detailed cross-sectional view of the lower wall of the retaining wall according to the present invention;

4 is a block diagram of a retaining wall construction method according to the present invention;

5 to 17 is a view showing the implementation of the retaining wall construction method according to the present invention.

* Description of the symbols for the main parts of the drawings *

1: Ground 2: Ground

3: shelf mounting surface 10: wall

10a: lower wall 10b: upper wall

11: shotcrete layer 11a: wire mesh

12: concrete layer 12a: reinforcing bars

20: shelf 30: thumbnail

31: pressure plate 34: stud

Claims (13)

A wall erected on the side of the cut ground; A shelf installed on the rear surface of the wall and embedded in the ground; A nail nail connecting the wall with the ground; Retaining wall comprising a. The method according to claim 1, Retaining wall, characterized in that the wall and the shelf is an integral reinforced concrete structure. The method according to claim 1, Retaining wall, characterized in that the plurality of small nails are installed on the lower wall based on the shelf. The method according to claim 1, The lower wall of the wall based on the shelf is made of an inner shotcrete layer and an outer concrete layer, a wire mesh to the shotcrete layer, connecting reinforcing bars fixed to the wire mesh, and a pressure plate mounted on the small nail And a nut for fixing the pressure plate is embedded. The method according to claim 1, Retaining wall, characterized in that the lower wall on the basis of the shelf in the wall is composed of a shotcrete layer of the inside and the concrete layer of the outside, the end of the nail nail is embedded in the concrete layer. The method according to claim 1, In the wall, the lower wall is composed of an inner shotcrete layer and an outer concrete layer based on the shelf, and a pressure plate is fixed to an end side of the small nail, and a stud is mounted on the pressure plate, and the stud is mounted on the concrete. Retaining wall, characterized in that embedded in the floor. The method according to claim 6, Retaining wall, characterized in that the head extending in the radial direction of the body at the end of the stud. The method according to claim 6, Retaining wall, characterized in that the stud is fixed to the reinforcement of the concrete layer. A small nailing step of inserting a small nail into the cut ground and placing a shotcrete layer; A lower wall construction step of constructing a lower wall connected to the small nail by pouring a concrete layer on the outside of the shotcrete layer; A shelf mounting surface forming step of providing a shelf mounting surface at the same height as the upper end of the lower wall; A shelf and an upper wall construction step of constructing a shelf and an upper wall integrally with the lower wall on the shelf mounting surface; A back filling step of filling the rear spaces of the upper and upper walls of the shelf; Retaining wall construction method comprising a. The method according to claim 9, Retaining wall construction method characterized in that for further mounting the stud on the pressure plate mounted on the small nail in the small nailing step, the lower wall construction step. The method according to claim 9, In the small nailing step, a plurality of small nails are inserted into the ground, retaining wall construction method, characterized in that inserted sequentially from the top to the bottom of the ground. The method according to claim 9, In the lower wall construction step, the reinforcing bar extending inside the lower wall is installed to extend outside the upper end of the lower wall, and then the reinforcing bar of the shelf and the upper wall is connected to the reinforcing bar of the lower wall in the shelf and upper wall construction step. Retaining wall construction method characterized in that the reinforcement. The method according to claim 9, Retaining wall construction method characterized in that the shelf and the upper wall construction step is to cast concrete into the integrally formed formwork.

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