KR20150050012A

KR20150050012A - Retaining Wall and Construction Method thereof

Info

Publication number: KR20150050012A
Application number: KR1020130131312A
Authority: KR
Inventors: 홍성진; 권오성; 송치용; 김성규
Original assignee: 대림산업 주식회사; 주식회사그라운드이엔씨
Priority date: 2013-10-31
Filing date: 2013-10-31
Publication date: 2015-05-08

Abstract

The present invention relates to a prestressed concrete retaining wall using a ground anchor and a construction method thereof to prevent a continuous wall from being bent by external forces such as earth pressure and water pressure as a concrete retaining wall is constructed by arranging two rows of multiple ground anchor bodies to be fastened by mesh reinforcement and pouring concrete and applying a tensile force to them. The prestressed concrete retaining wall using a ground anchor comprises: a lower anchorage as anchor bodies fastened to the front end of a strand joined to a sheath pipe to be arranged in two rows below the mesh reinforcement inserted into an excavation hole; an underground wall in which the mesh reinforcement and the lower anchorage are buried; and an upper anchorage which applies tension to the strand from the top of the underground wall to anchor the head of the underground wall.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a prestressed concrete retaining wall using a ground anchor,

The present invention relates to a prestressed concrete earth retaining wall using a ground anchor and a method of constructing the same. More specifically, when constructing a concrete retention wall, a plurality of ground anchors are formed by using a reinforcing net, The present invention relates to a prestressed concrete earth retaining wall using a ground anchor and a method of constructing the earth retaining wall using a ground anchor, by which a concrete earth retaining wall can be effectively prevented from being bent by an external force such as earth pressure or water pressure.

Excavation of the ground such as the construction of large civil engineering underground structures such as high-rise buildings, apartments, houses, and water tanks, excavation of the ground to construct underground structures including underground walls, underground floor slabs, underground foundation slabs, In order to prevent collapse of the excavation site according to excavation depth and geotechnical characteristics, various types of earth retaining means are used, and as the earth retaining means, an underground continuous wall type earth wall is constructed. Such an underground continuous wall type earth retaining wall is capable of low vibration and low noise construction, has a low incidence of complaints due to the prevention of adjacent ground settlement, and has an advantage of high safety due to high stiffness of the wall constituting the earth wall. In addition, the maximum construction depth of 80 ~ 100 m is possible, so that it is possible to freely select the dimension and the shape of the wall section without receiving the design restriction according to the depth of excavation, and the geological condition of rock excavation (rock layer possible) It can be used in conjunction with the underground construction method of underground structures (construction method that allows construction of underground structures and superstructures in parallel) and can be used as the main wall of underground structures. It has the advantage that the surrounding ground is not scattered due to high index. For this reason, it is widely used in spite of the relatively low construction cost, a large number of incidental equipment, and some disadvantages that the construction site needs more than a specific area.

In order to construct a conventional earth wall in the form of an underground continuous wall, first, after surveying and site arrangement for the site where the earth retaining wall is to be formed, such as a site boundary line, a guide wall is installed. Then, a drill hole is formed by using a backhoe (hydro-mill) suitable for the ground characteristics up to a predetermined depth based on the guide wall. A reinforcing assembly (field or factory) to be embedded in the earth retaining wall is inserted into the excavation hole with a pounding device such as a crane or the like and then the concrete pavement installed up to the lower part of the excavation hole is lifted up to a certain height, To form a wall so that the steel assembly is embedded in the concrete, and the concrete is cured to finally complete the earth retaining wall in the form of an underground continuous wall. d The method of constructing the earth retaining walls by continuously forming the earth retaining walls in the shape of the underground continuous wall along the site boundary is usually called the diaphragm wall or slurry wall construction method.

Since the subterranean continuous wall is formed up to the designed depth and continuously formed along the site boundary line in the transverse direction (width direction), the finally completed shape is formed by the subterranean continuous wall along the outline of the site where the structure is constructed It becomes a fence type. Therefore, even if the portion enclosed by the underground continuous wall is excavated, the collapse of the ground supported on the backside of the underground continuous wall is prevented, so that the underground structure is safely installed at the portion surrounded by the underground continuous wall, .

However, such a continuous continuous wall undergoes a bending moment due to an external force such as earth pressure and water pressure applied from its backside, and when the bending moment exceeds the flexural stiffness due to the underground continuous wall itself, the continuous continuous wall itself collapses, There is also a problem that the ground collapses together. Therefore, there is always a risk of large safety accidents when there are many structures on the land boundaries, such as urban areas.

As a countermeasure against this, conventionally, a wale is installed on the entire surface of the underground continuous wall horizontally across the underground continuous wall, and the strut is installed horizontally or inclined on the wale, And a method of supporting an underground continuous wall in an auxiliary manner was used. However, in case of using such support material, since the support material is disposed in the space where the underground structure should be installed, it interferes with the construction of the underground structure by eroding the space for installing the underground structure. Therefore, it is necessary to dismantle the support materials in the process of constructing the underground structures. Eventually, the installation and disassembly of the support materials adversely affect the construction and air of the underground structures and cause the increase of the construction cost.

SUMMARY OF THE INVENTION The present invention has been developed in order to overcome the above-mentioned problems of the related art, and it is an object of the present invention to provide a method of installing a concrete earth retaining wall by arranging a plurality of ground anchors, The present invention provides a prestressed concrete earth retaining wall using a ground anchor that blocks a continuous wall from being bent by an external force such as earth pressure or water pressure by applying a tensile force after pouring concrete, and a method of constructing the same.

In order to accomplish the above object, the present invention provides a lower fixture comprising two rows of anchors arranged at the ends of a strand connected with a sheath pipe below a reinforcing net inserted into a drill hole, An underground wall formed so that a lower fixation port is embedded therein, and an upper fixation port fixing a head after tension is applied to the upper end of the underground wall by a stranded wire.

Specifically, in the present invention, a lower fixation port is provided in which two rows of anchors are fastened to ends of a strand connected with a sheath pipe to the lower side of a reinforcing net inserted into a drill hole; An underground wall formed so that the reinforcing net and the lower fixture are embedded in the inner wall; A prestressed concrete earth retaining wall using a ground anchor is provided, wherein the prestressed concrete retaining wall is constituted by an upper fixture for fixing the head after applying tension to the strand at the upper end of the underground wall.

According to another aspect of the present invention, there is provided a method of constructing an excavation apparatus, the method comprising: forming an excavation hole in which an underground wall is formed along a site boundary; Inserting the reinforcing net into the excavating hole after arranging the anchor bodies having the reinforcing net inserted into the excavating hole into which the shear pipe is inserted, in two rows; Forming a concrete wall in the ground by pouring and curing the concrete with the reinforcing net; And applying a compressive prestress to the underground wall by tensioning the tensile material at the upper end of the concrete wall to thereby introduce a compressive prestress into the underground wall, thereby providing a method of constructing a prestressed concrete earth retaining wall using a ground anchor.

In the prestressed concrete earth retaining wall and the method of constructing the same according to the present invention, the lower fixation port may have a structure in which a lower portion of the strand with the sheath pipe inserted therein is exposed to the outside, The lower fixture may have a construction in which a support plate is fastened to the tip of a strand of the strand, and the support plate and the strand are fastened by a compression grip, a wetch and a U-turn method.

Further, in the present invention, the lower fixing unit may have a structure in which a plurality of strands are connected to one inner lower body, and a strand is fixed using a compression grip, a wetch and a U-turn method. In this case, So as to disperse the load.

Further, in the present invention, when the strand is long, a connecting coupler may be provided for connecting two strands of wire. In this case, the connecting coupler may be formed with a wachi insert hole for inserting a plurality of wachi, An upper head; A lower head which is threaded with the upper head and has wedge insertion holes for inserting a plurality of wedges; A wedge provided symmetrically with the wedge insertion holes of the upper and lower heads, an elastic spring provided on the surface of the wedge, and a fastener consisting of a single diaphragm provided between the elastic springs; And a stranded wire inserted into the wedge and having a cladding tube on its outer surface. Particularly, the connecting coupler is inserted into a case having threads at the upper and lower inner surfaces of the upper and lower ends thereof and has a through hole penetrating the inside of the case, And a grip may be provided on one of the wachies provided symmetrically to each other on the wachi insert holes of the upper and lower heads. Furthermore, a cap having a closed surface on the rear surface of the wetch may be provided, and a cap having a surface open on the rear surface of the wetch may be provided.

The upper and lower heads may have an outer coupler connected to the outer surface of the upper and lower heads. Alternatively, the fixing plates may be fixed to the rear of the elastic springs installed on the upper and lower heads. Grips can be installed and used.

The present invention has the following effects.

First, since a plurality of ground anchors arranged in two rows by a reinforcing net are fastened and a prestress is introduced, there is an effect that the concrete earth retaining wall is not deformed by earth pressure or water pressure, and thus safety is excellent.

Second, when the length of the excavation hole is long, the strand of the anchor body installed in the reinforcing net is connected by using the connecting coupler, so that it is possible to prevent the warp of the strand.

1 is a schematic view showing a state of installing a prestressed concrete earth retaining wall using a ground anchor according to the present invention.
2 is a schematic cross-sectional view showing the entire configuration of the present invention.
Figures 3 to 17 are schematic diagrams illustrating cross-sectional views of the components of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Although the present invention has been described with reference to the embodiments shown in the drawings, it is to be understood that the technical idea of the present invention and its essential structure and operation are not limited thereby.

Fig. 2 is a cross-sectional view showing the entire configuration of the present invention, and Figs. 3 to 17 are schematic views showing a cross-sectional view of the components of the present invention. Reference numeral 100 in the drawings attached to the specification shows the body of the concrete earth retaining wall of the present invention.

The main body 100 is composed of a lower fixation port 10, a tension member (strand) 20, and an upper fixation port 150.

As shown in FIG. 1, in the present invention, a guide wall is provided to accurately form an excavation hole in which an underground wall is installed in a site where an underground wall such as a site boundary should be formed. Then, the excavation hole 2 is formed by using the excavation apparatus 1 having the depth characteristics up to a predetermined depth based on the guide wall. Inside the excavation hole (2), a reinforcing net (3) manufactured from the outside is inserted and installed using a crane (4).

As shown in FIG. 2, the lower fixing port 10 and the upper fixing port 150 are fixed to the reinforcing net 3. The lower fixture 10 covers the sheath tube 21 to the outside of a tensile member 20 such as a stranded wire formed by twisting a plurality of steel wires and the wedge is inserted into the tensile member 20 to be inserted into the wedge hole of the anchor member 30 And is fixedly installed. The anchors 30 installed in the lower fixing port 10 are fixed to the lower side of the reinforcing net 3 in this manner.

3, the anchor bodies 30 of the lower fixation port 10 are arranged in two rows in the lower fixation port 10 and staggeredly arranged in a zigzag form, as shown in FIG. 3 Is preferable. This is because the arrangement of two rows is more preferable than the arrangement of one row because the compressive force or tensile force of the concrete acts differently depending on the depth of the concrete earth retaining wall. However, the present invention is not limited thereto.

Another example of installation of the lower fixture 10 installed in the reinforcing net 3 will be described below.

4, the shrink tube 21 is removed from the lower portion of the strand 20 coated with the sheath tube 21 to expose the strand 20 to the outside, and a plurality of Arrange the dog vertically. In this structure, the strand 20 exposed to the outside is adhered to the poured concrete to form a fusing field, and the portion covered with the remaining sheath pipe is not attached to the concrete by the sheath tube 21, do.

In this state, when the strand 20 is pulled from the ground surface, the tensile force is transferred to the free field as it is, and the load is transferred to the concrete from the beginning of the settlement field, and a prestress (compressive force) is introduced into the concrete earth retaining wall after fixing.

Further, as shown in FIG. 5, a circular pressure plate 40 having a plurality of holes formed therein is fastened to the front end of the strand 20. Then, the strand 20 is fixed to the pressure plate 40 by using the pressing grip 41 or the wedge 42, or the strand is fastened by a U-turn method. In this configuration, since the entire strand 20 is covered with the sheath tube 21, the tensile force applied from the earth surface is transferred from the front end of the concrete retention wall to the concrete, and a prestress (compressive force) is introduced into the undergoing continuous wall .

6, the lower fixture 10 is formed by connecting a plurality of strands 20 to one inner lower body 50 and connecting the strands 20 to each other using a compression grip 51 or a wedge 52 or U Settling using turn system. As shown in FIG. 7, the inner bottom body 50 can be installed in multiple ways. Since the one or more inner lower bodies 50 are installed as described above so that concentrated loads do not act on the ends of the concrete earth retaining walls and are dispersed and the entire strand 20 is covered with the sheath tube 21, The prestress (compressive force) is introduced into the underground continuous wall after the settlement is transferred to the concrete through the inner bottom body installed inside the underground continuous wall. As described above, in the present invention, various types of lower fixing holes 10 are installed at the lower end of the reinforcing net 31.

When the length of the strand 20 to be fastened to the anchor body of the lower fixture 10 is long, as shown in FIG. 8, two strands 20 are connected to each other by using a separate connection coupler 60. The connecting coupler 60 is formed with an upper head 70 having a wedge insertion hole 72 for receiving a plurality of wedges 71 and a threaded portion 73 formed on an inner peripheral surface thereof. A wedge insertion hole 81 is formed to be inserted into the upper head 70 and a plurality of wedges 81 are inserted thereinto and a lower head 80 having a thread 83 formed on the outer circumferential surface thereof. The wedges 71 and 81 are provided symmetrically with the wedge insertion holes 72 and 82 of the upper and lower heads 70 and 80 and the elastic springs 74 are fixed to the surfaces of the wedges 71 and 81, A fastener 86 having a single diaphragm 85 is provided between the elastic springs 74 and 84 after the spring 84 is installed. The stranded wire 20 having the sheath tube 21 is inserted into the outer surfaces of the wedge insertion holes 72 and 82 of the upper and lower heads 70 and 80 to be fixed to the wachies 71 and 81 .

9, the connecting coupler 60 is inserted into the case 90 having the thread 92 at the upper and lower inner surfaces of the case 90 while having the through hole 91 penetrating the inside of the case 90 Upper and lower finishing plates 94 and 95 having a plurality of insertion holes 93 into which the stranded wire 20 is inserted are used by being screwed to the upper and lower ends of the upper and lower ends of the upper and lower end plates 94 and 95, respectively.

One of the wachies 71 and 81 symmetrically disposed on the wachy insertion holes 72 and 82 of the upper and lower heads 70 and 80 is provided with a compression grip 110 are used to fix the strand 20.

A cap 112 having a surface clogged as shown in FIG. 11 is formed on the rear surface of the wedges 71 and 81 inserted into the wochi insert holes 72 and 82 of the upper and lower heads 70 and 80, Or a cap 113 whose surface is opened as shown in FIG. 12 may be installed.

Further, another outer coupler 120 may be fastened to the outer surfaces of the upper and lower heads 70 and 80. [ As shown in FIG. 13, the outer coupler 120 is formed with a through hole passing through the center, and a thread 122 is formed on the inner peripheral surface of the through hole. The upper head 70 is screwed to the upper side of the external coupler 120 and the lower head 80 is screwed to the lower side.

At this time, the wedges 71 and 81 are inserted into the wedge insertion holes 72 and 82 of the upper and lower heads 70 and 80 and the elastic springs 74 are inserted into the surfaces of the wedges 71 and 81, (84).

A cap 112 having a surface embedded in the inner rear surface of the wedges 71 and 81 is provided and the diaphragm 85 is installed in a space between the elastic springs 74 and 84. At this time, the cap 112 may be a cap that is open to the surface.

The fixing plates 130 are fixed to the rear of the elastic springs 74 and 84 instead of the one diaphragm 85 by using bolts 131 as shown in FIG.

Instead of the wachies 71 and 81 for holding the strand 20 in the wachy insertion holes 72 and 82 of the upper and lower heads 70 and 80 connected to the external coupler 120, And the strand 20 is fixedly fastened using the fastener 110.

After the lower fixture 10 is installed in the reinforcing net 3 in various ways as described above, the reinforcing net 3 is inserted into the excavation hole 2 by using a crane, as shown in FIGS.

The concrete pipe 140 is poured into the reinforcing net 3 and the concrete pipe 140 is discharged to the outside, and then the concrete pipe 140 is cured for a predetermined period to form the underground wall 20.

In this state, the upper fixture 30 is tightened with strands arranged in two rows of the underground wall 20, and then the prestress is applied to the underground wall 20 by tensing.

At this time, the upper fixing unit 150 is fixed by using the wedge 152 to which the spring 151 is attached.

Thereafter, the intermediate portion of the preceding work is re-excavated and the subsequent work is performed in a manner similar to the above-described method, thereby completing the continuous underground wall.

The construction method of the prestressed concrete earth retaining wall using the ground anchor according to the present invention is summarized as follows.

First, a guiding wall is installed so that an excavation hole for an underground wall can be precisely formed after surveying and site clearance for a site where an underground wall (underground wall / earth retaining wall) such as a site boundary is to be formed.

The excavation hole is formed on the guide wall using a drilling apparatus having a predetermined depth up to a predetermined depth based on the guide wall.

And the ends of the strands to which the sheath pipe is connected are arranged in two rows of the anchor sutures, which are connected to the lower side of the reinforcing net inserted into the excavating hole. At this time, when the depth of the excavation hole is deep and it is difficult to use one strand, the two strands can be connected using a connecting coupler connecting the two strands.

After inserting the reinforcing net in which the anchor body is fastened into the digging hole, the concrete pipe is inserted into the reinforcing net, and concrete is cured and then cured for a certain period to complete the underground wall.

In this state, the upper fixture is fastened to the upper surface of the underground wall by two rows of strands, and then the prestress is applied and fixed to the underground wall.

3: Reinforcing mesh
21: Sheath tube

Claims

A lower fixture having two rows of anchors arranged at the lower side of a reinforcing net inserted into a drill hole and having a sheath pipe coupled to the end of a strand;
An underground wall formed so that the reinforcing net and the lower fixture are embedded in the inner wall;
And an upper fixing unit for fixing the head after applying tensile force to the strand at an upper end of the underground wall, wherein the upper anchor is used for the prestressed concrete earth retaining wall.

The method according to claim 1,
Wherein the lower fixation port exposes a lower portion of the strand where the sheath pipe is inserted to the outside and then fastens a plurality of the strands in two rows to the reinforcing net.

The method according to claim 1,
Wherein the lower fixation port is a prestressed concrete earth retaining wall using a ground anchor, characterized in that a support plate is fastened to the front end of a strand of the strand, and the support plate and the strand are fastened by a compression grip, a wetch and a U-turn method.

The method according to claim 1,
Wherein the lower fixation port connects a plurality of stranded wires to one inner lower body and fixes the stranded wire using a compression grip, a wetch, and a U-turn method.

5. The method of claim 4,
Wherein the inner bottom body is provided in multiple so as to disperse the load. [3] The prestressed concrete earth retaining wall using the ground anchor according to claim 1,

The method according to claim 1,
And a connecting coupler for connecting two strands of the strand to each other when the strand is long.

The method according to claim 6,
The connection coupler includes:
An upper head having a wachihe insertion hole formed therein for inserting a plurality of wekes and having a thread on an inner circumferential surface thereof;
A lower head which is threaded with the upper head and has wedge insertion holes for inserting a plurality of wedges;
A wedge provided symmetrically with the wedge insertion holes of the upper and lower heads, an elastic spring provided on the surface of the wedge, and a fastener consisting of a single diaphragm provided between the elastic springs;
And a stranded wire inserted into the wedge and having a cladding tube on an outer surface thereof.

8. The method of claim 7,
The connecting coupler is inserted into a case having threads on the inner and lower ends of the upper and lower ends of the case and has upper and lower finish plates having a plurality of insertion holes into which the strands are inserted at the upper and lower ends of the case, Wherein the ground anchor is used to connect the prestressed concrete retaining wall.

8. The method of claim 7,
Wherein a grip is provided on one of the wachies provided symmetrically with respect to the wachy insertion holes of the upper and lower heads, wherein the prestressed concrete earth retaining wall using the ground anchor.

8. The method of claim 7,
And a cap having a surface clogged by the rear surface of the wedge is installed. The prestressed concrete earth retaining wall using the ground anchor.

11. The method of claim 10,
And a cap having a surface open to the rear surface of the wedge is installed. The prestressed concrete earth retaining wall using the ground anchor.

8. The method of claim 7,
And an outer coupler is fastened to the outer surfaces of the upper and lower heads to use the prestressed concrete earth retaining wall using the ground anchor.

13. The method of claim 12,
And a fixing plate is fixedly installed to the rear of the elastic spring provided on the upper and lower heads to use the prestressed concrete earth retaining wall using the ground anchor.

13. The method of claim 12,
And a grip is provided by the insertion hole of the upper and lower heads, and is used for the ground anchor.

Forming an excavation hole in which an underground wall is formed along a site boundary line;
Inserting the reinforcing net into the excavating hole after arranging the anchor bodies having the reinforcing net inserted into the excavating hole into which the shear pipe is inserted, in two rows;
Forming a concrete wall in the ground by pouring and curing the concrete with the reinforcing net;
And then compressing the tensile material at the upper end of the concrete wall and then fixing the tensioned material, thereby introducing the compression prestress into the underground wall.

16. The method of claim 15,
And a connecting coupler connecting the strands of the anchor body to the reinforcing net if the length of the strand of the anchor body is longer than the length of the strand of the anchor body.