KR102726600B1 - Construction method of wale type earth retaining wall capable of installing high angle anchor using curvature supporting plate - Google Patents

Abstract

The present invention relates to a method for constructing a retaining wall, and more particularly, to a method for constructing a belt-type retaining wall in which an earth anchor is installed at a high angle in a minimum space, a curved support is installed on a thumb pile and a horizontal belt installed on the top of the thumb pile, the steel wire of the earth anchor installed at a high angle is guided to the curved support so that it is horizontally tensioned in an anchor reaction band installed on the horizontal belt, thereby allowing the high-angle earth anchor to receive the entire horizontal component of force, and the steel wire is guided to different heights on the curved support so as to increase the area of contact surface according to the bending of the steel wire, thereby minimizing wear of the steel wire that may occur at point contact.

Description

{CONSTRUCTION METHOD OF WALE TYPE EARTH RETAINING WALL CAPABLE OF INSTALLING HIGH ANGLE ANCHOR USING CURVATURE SUPPORTING PLATE}

The present invention relates to a method for constructing a retaining wall, and more particularly, to a method for constructing a belt-type retaining wall in which an earth anchor is installed at a high angle in a minimum space, a curved support is installed on a thumb pile and a horizontal belt installed on the top of the thumb pile, the steel wire of the earth anchor installed at a high angle is guided to the curved support so that it is horizontally tensioned in an anchor reaction band installed on the horizontal belt, thereby allowing the high-angle earth anchor to receive the entire horizontal component of force, and the steel wire is guided to different heights on the curved support so as to increase the area of contact surface according to the bending of the steel wire, thereby minimizing wear of the steel wire that may occur at point contact.

The current state of land use in our country is mainly concentrated in large cities, and due to the lack of available land, high-rise buildings and high-density urban areas are accelerating.

As the scale of underground structures such as buildings, civil engineering structures, and pipelines increases due to high-rise and high-density land use, construction in close proximity to nearby buildings is inevitable. Therefore, when excavating underground structures, subsidence of adjacent roads, tilting, cracking, and collapse of nearby buildings frequently occur, and many social problems arise due to property losses, numerous public complaints, and civil and criminal disputes.

Therefore, in order to construct an underground structure at a lower level than the ground, the ground is excavated. This can be broadly divided into the open cut method, in which the ground is excavated at a certain gradient within a range where the stability of the ground is secured, and the method in which the ground is excavated at a right angle using a retaining wall.

Earth anchor construction is commonly used to maintain earth retaining walls when excavating deep ground for the construction of underground structures.

Here, the above-mentioned earth anchor method has the problem that it cannot be applied when the site area is narrow, although it fixes the earth anchor by penetrating the adjacent site by more than 10 m.

To solve the problems of this earth anchor method, a method of installing the earth anchor at a high angle has been disclosed, such as in Korean Patent Publication No. 10-2016-0002620 and Korean Patent Registration No. 10-2476068.

The above-mentioned domestic patent publication No. 10-2016-0002620, an earth retaining structure and a construction method thereof, relates to an earth retaining structure supported by a plurality of piles (10), as illustrated in FIG. 1, and comprises: a support pile (100) that forms all or part of the plurality of piles (10) and is embedded so as to have an embedded depth (D) of at least three times that of a virtual fixed point based on the maximum excavation depth (H) of the ground so as to form a fixed end at the lower end; a hinge portion (200) formed at the upper end of the support pile (100); and a tension member (300) embedded so that the upper end is coupled to the hinge portion (200) and the lower end is inclined downward toward the back soil; thereby enabling the earth retaining structure to be stably applied even in cases where it is difficult to secure sufficient space on the back side.

However, since these conventional earth retaining structures and their construction methods apply a large amount of vertical force to the thumb pile, the self-compressive stress of the thumb pile increases, and also, due to the increase in vertical force, a greater bearing capacity is required, and when the thumb pile head is completely poured with concrete, a considerable portion of the horizontal force is absorbed as a reaction force of the ground, making it difficult to provide horizontal prestress.

In addition, the retaining wall structure using the multi-directional anchor fixing device, which is the domestic patent registration No. 10-2476068, and the construction method thereof, as shown in FIGS. 2 and 3, meanwhile, the multi-directional anchor fixing device (4) is a component installed on the upper part of the main upright pile (1) to minimize the bending moment of the main upright pile (1) (reduce bending), and comprises an anchor fixing means (41) installed on the main upright pile, and an underground anchor member (42) having one end connected to the anchor fixing means (41) and the other end installed in the ground, and an anchor arrangement angle adjusting member (413) is formed as a curved member that is connected obliquely to the anchor introduction plate (4123) and has an anchor guide curved groove (4133) formed so as to be connected to the anchor introduction hole (4124). Here, the anchor placement angle adjustment member (413) is applied by forming a straight section (4131) and a curved section (4132) using a bar (a shape in which a pipe is cut in half) having a hemispherical cross-section.

However, a retaining wall structure using a multidirectional anchor fixing device and a construction method thereof are such that all the steel wires of an earth anchor are guided from an anchor arrangement angle adjustment member and inserted into the fixing holes of each anchor fixing member. However, the steel wires guided to the fixing holes provided on the upper part of the anchor fixing member cannot help but come into point contact with the anchor arrangement angle adjustment member. As a result, there is a problem that a large amount of stress is generated in the steel wires, and fatigue stress of the steel wires accumulates due to continuous stress, which may cause fracture.

Domestic Publication of Patent Publication No. 10-2016-0002620 Domestic Patent Publication No. 10-2476068

The present invention is to solve the above problems, and the purpose of the present invention is to provide a method for constructing a belt-type earth retaining wall in which an earth anchor is installed at a high angle in a minimum space, a curved support is installed on a thumb pile and a horizontal belt installed on the top of the thumb pile, the steel wire of the earth anchor installed at a high angle is guided to the curved support so that it is horizontally tensioned in an anchor reaction band installed on the horizontal belt, so that the high-angle earth anchor receives the entire horizontal component of force, and the steel wire is guided to different heights on the curved support so as to increase the area of contact surface according to the bending of the steel wire, thereby minimizing wear of the steel wire that may occur at point contact.

In addition, the present invention has another purpose of providing a method for constructing a belt-type retaining wall in which a detachable expanded floor plate for expanding the bearing capacity is installed under a thumb pile to prevent subsidence due to insufficient bearing capacity at the tip, and a curved support that is advantageous for pulling out the thumb pile for reuse enables the installation of high-angle anchors.

In addition, the present invention has another purpose of providing a method for constructing a belt-type retaining wall capable of installing high-angle anchors, in which an elastic band is installed on the outside of the steel wire in contact with a curved support to protect the steel wire and minimize stress, thereby preventing breakage.

The features of the present invention to achieve the above purpose are:

A method for constructing a retaining wall in which thumb piles and earth anchors are installed in a space of less than 10 m from an adjacent site due to a narrow site area, comprising: a ground boring process for forming a thumb pile insertion hole for inserting the thumb pile into the ground; a thumb pile insertion process for inserting the thumb pile into the thumb pile insertion hole with the upper end protruding and then injecting filler into the space; an earth anchor installation process for forming an anchor insertion hole with an incline by inserting a rod of a boring device into the ground between the thumb piles and into the inside of a land boundary line with the adjacent site and then fixing the earth anchor; a structure installation process for installing a horizontal belt at the upper and lower front sides of the upper portions between the thumb piles and the thumb piles, installing a curved support for guiding steel wires located at the upper and lower ends of the earth anchor to different heights on the back side of the horizontal belt, and installing an anchor reaction support on the front side of the belt in the same line as the curved support; It is characterized by including an earth anchor tensioning process of guiding the steel wire of the above earth anchor to the curved support, passing through the horizontal belts, and introducing it into the anchor reaction zone to tension and fix the steel wire in the anchor reaction zone; and an excavation process of excavating the ground to a design depth.

Here, the method for constructing a belt-type retaining wall capable of installing high-angle anchors using the above-mentioned curved support further includes a brace installation process of installing a brace on the thumb pile or horizontal belt during the above-mentioned excavation process; and a pulling process of pulling out and removing the thumb pile so that the thumb pile can be reused after the underground structure is constructed after the excavation is completed.

Here also, the above-mentioned ground boring process is bored vertically or with the bottom having an incline of less than 20° in the excavation direction based on the ground horizon to resist the horizontal force of earth pressure.

Here again, in order to increase the bearing capacity by increasing the cross-sectional area on the bottom surface, the thumb pile is integrated by point welding only a portion of the detachable expanded floor plate into which the thumb pile is inserted and joined while being spaced apart, and when the thumb pile is pulled out, a blow is applied to remove the point welded portion, so that only the thumb pile is pulled out.

Here, the earth anchor also has an elastic band installed on the outside of the steel wire in contact with the curved support to reduce stress.

Here, the curved support is formed with a support plate having a high front side, a low back side, and a through hole formed in the center of the back side; a first curved plate installed in the center of the support plate to guide the lower steel wire of the earth anchor; and a second curved plate installed in the upper part of the support plate to guide the upper steel wire of the earth anchor.

According to the method for constructing a belt-type retaining wall capable of installing high-angle anchors using the curved support of the present invention configured as described above, an earth anchor is installed at a high angle in a minimal space, and the curved support is installed on a thumb pile and a horizontal belt installed on the top of the thumb pile so that the steel wire of the earth anchor installed at a high angle is guided to the curved support so that it is horizontally tensioned in the anchor reaction band installed on the horizontal belt, thereby allowing the high-angle earth anchor to receive the entire horizontal component of force, and by guiding the steel wire at different heights on the curved support, the area of the contact surface according to the bending of the steel wire can be increased, thereby minimizing wear of the steel wire that may occur at point contact.

In addition, the present invention prevents subsidence due to insufficient tip bearing capacity by installing a detachable expansion bottom plate for expanding bearing capacity under a thumb pile, and enables easy pulling out of the thumb pile for reuse, thereby enabling reuse of the thumb pile, thereby reducing construction costs.

In addition, according to the present invention, an elastic band is installed on the outer side of the steel wire in contact with the curved support to protect the steel wire and minimize stress, thereby preventing breakage.

Figures 1 to 3 are drawings for explaining a conventional soil retaining wall construction method.
FIG. 4 is a perspective view showing a structural configuration applied to a belt-type retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention.
FIG. 5 is a cross-sectional view showing the configuration of a thumb pile applied to a belt-type retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention.
Figure 6 is a partially enlarged view of Figure 5.
FIG. 7 is a perspective view showing the configuration of a curved support applied to a belt-type earth retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention.
Figure 8 is a process diagram for explaining a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention.
FIGS. 9 and 10 are explanatory drawings for explaining a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention.
FIG. 11 is a drawing showing a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention according to another embodiment of the present invention.

Hereinafter, a structure applied to a belt-type earth retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention will be described in detail with reference to the attached drawings.

In the following description of the present invention, if it is judged that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present invention, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification.

FIG. 4 is a perspective view showing a structure configuration applied to a belt type soil retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention, FIG. 5 is a cross-sectional view showing a configuration of a thumb pile applied to a belt type soil retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention, FIG. 6 is a partial enlarged view of FIG. 5, and FIG. 7 is a perspective view showing a configuration of a curved support applied to a belt type soil retaining wall construction method capable of installing high-angle anchors using a curved support according to the present invention.

First, the thumb pile (10) is basically applied as an H beam or a II beam.

As shown in Fig. 5, the thumb pile (10) is inserted and joined to a detachable expanded floor plate (11) to increase the cross-sectional area on the floor surface and to increase the bearing capacity, and only a portion of the thumb pile (10) is point-welded while leaving a gap (g, approximately 0.5 cm) between the thumb pile (10) and the point welded portion is removed by applying a blow when the thumb pile (10) is pulled out, so that only the thumb pile (10) can be easily pulled out and reused.

And, the horizontal belt (20) is installed horizontally on the top of a pair of thumb stakes (10) in a conventional H beam structure as shown in FIGS. 4 and 5. At this time, it is preferable to install an angle (21) on the horizontal belt (20) located at the bottom among the horizontal belts (20).

In addition, the anchor reaction belt (30) has a frame structure with an open back surface so that the steel wire (W) of the earth anchor (A) can pass through it as shown in FIGS. 4 and 5, and an inlet hole (31) is formed on the front surface into which the steel wire (W) is introduced, and an anchor cone (33) is installed on the front surface of the inlet hole (31) to tension the steel wire (W) in the horizontal direction.

Next, the curvature support (40) is composed of a support plate (41), a first curvature plate (43), and a second curvature plate (45) as shown in FIGS. 5 to 7.

The support plate (41) is formed with a high front and low back, and a through hole (41a) is formed in the center of the back surface to allow a steel wire (W) to pass through, and is installed on the back surface of the horizontal belt (20).

The first curved plate (43) is installed in the center of the support plate (41) to guide the lower steel wire (W) of the earth anchor (A).

The second curvature plate (45) is installed on the upper part of the support plate (41) to guide the upper steel wire (W) of the earth anchor (A). At this time, the second curvature plate (45) may have the same curvature as the first curvature plate (43) or may be formed with different curvatures.

Hereinafter, a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention will be described in detail with reference to the attached drawings.

FIG. 8 is a process diagram for explaining a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention, FIGS. 9 and 10 are explanatory diagrams for explaining a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention, and FIG. 11 is a drawing showing a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention, according to another embodiment of the present invention.

Referring to FIGS. 8 to 11, a method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention comprises a ground drilling process (S10), a thumb pile insertion process (S20), an earth anchor installation process (S30), a structure installation process (S40), an earth anchor tensioning process (S50), an excavation process (S60), and a pulling process (S70). At this time, the pulling process (S70) can be constructed selectively, and is described below in its entirety.

First, the method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support according to the present invention is used when excavating a site of less than 10 m, and is applied to the method for constructing a retaining wall in which thumb piles and earth anchors are constructed in a space of less than 10 m from an adjacent site because the site area is narrow.

《Ground Drilling-S10》

As shown in (a) of Fig. 9, a perforation hole (H1) for inserting a thumb pile (10) into the ground is formed.

The perforation hole (H1) for inserting the thumb pile may be perforated vertically in the ground by a perforation device, or may be perforated with an incline of less than 20° with respect to the ground horizon as shown in Fig. 11 to reduce the earth pressure applied to the thumb pile (10) and increase the horizontal force of the earth anchor (A).

《Thumb Peg Insertion Process-S20》

When the ground drilling is completed, as shown in (b) of Fig. 9, the thumb pile (10) is lifted by a lifting device and inserted into the thumb pile insertion drilling hole (H1), and then filler (F, soil, sand, mortar, etc.) is injected into the space between the thumb pile insertion drilling hole (H1) and the thumb pile (10).

In addition, the upper part of the thumb stake (10) is made to protrude higher than the ground so that a horizontal belt (20) is installed at the upper part of the thumb stake (10).

《Anchor Insertion Process-S30》

When the insertion of the thumb pile (10) is completed, as shown in (c) of Fig. 9, the rod of the drilling equipment is inserted into the ground between the thumb piles (10) and the boundary line of the adjacent site to form a drilling hole (H2) for anchor insertion, and then the rod is removed.

Then, the steel wire (W) and packer (P) of the earth anchor (A) are inserted into the anchor insertion hole (H2), and then grout material is injected into the packer (P) to fix it.

《Structure Installation Process-S40》

Next, as shown in (d) of Fig. 9, a horizontal belt (20) is installed at the upper end between the thumb piles (10) and the thumb piles (10), and a curved support (40) is installed on the back surface of the horizontal belt (20) to guide the steel wires (W) located at the upper and lower ends of the earth anchor (A) to different heights, and an anchor reaction force member (30) is installed on the front surface of the horizontal belt (20) in the same line as the curved support (40).

《Earth Anchor Tensile Process-S50》

When the structure installation is completed, as shown in (e) of Fig. 10, an elastic band (50) is attached to the part where the upper part of the steel wire (W) of the earth anchor (A) comes into contact with the curved support (40), the upper part of the steel wire (W) is bent at the curved support (40) and passed through the horizontal belt (20), and then tensioned and fixed using an anchor cone (33) at the anchor reaction member (30).

《Excavation Process-S60》

When the tension of the earth anchor (A) is completed in the anchor reaction belt (30), the ground is excavated to the design depth based on the thumb pile (10) as shown in (f) of Fig. 10. At this time, it is preferable to excavate only to a height of 1 m from the bottom surface of the thumb pile (10). At this time, it is preferable to install a brace (not shown) on the thumb pile (10) or the horizontal belt (20). The brace may be installed horizontally at the corner as a conventional structure, or may be installed in the longitudinal or transverse direction.

《Induction Process-S70》

After the excavation is completed, as shown in (g) of Fig. 10, the thumb pile (10) is pulled out after the construction is completed so that the detachable expanded bottom plate (11) attached to the bottom surface is removed, and only the thumb pile (10) is pulled out by striking it with a lifting device to lower the thumb pile (10) by a distance so that the point weld portion is removed, and only the thumb pile (10) is pulled out and reused. At this time, the detachable expanded bottom plate (11) cannot be discharged from the thumb pile insertion hole (H1) due to the resistance of the filler.

The present invention is capable of various modifications and takes many forms, and in the above detailed description of the invention, only specific embodiments thereof have been described. However, it should be understood that the present invention is not limited to the specific forms mentioned in the detailed description, but rather should be understood to include all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

10 : Thumb peg 20 : Horizontal belt
30: Anchor counterforce 40: Curved support
50 : Elastic band 60 : Brace
A: Earth anchor W: Kang Yeon-seon

Claims (6)

In the construction method of a retaining wall where the site area is narrow and thumb piles and earth anchors are installed in a space of less than 10 m from the adjacent site,
A ground drilling process for forming a thumb pile insertion hole to insert the thumb pile into the ground;
A thumb pick insertion process of inserting the thumb pick into the thumb pick insertion hole with the upper end protruding and then injecting filler into the space;
A horizontal belt installation step of installing a horizontal belt on the upper and lower front sides between the thumb stakes and the thumb stakes;
An earth anchor installation process in which a rod of a drilling device is inserted into the ground between the thumb piles and the thumb piles to form a drilling hole for anchor insertion with an incline inward from the land boundary line with an adjacent site, and then an earth anchor is fixed, while an elastic band is installed on the outside of the steel wire of the earth anchor to reduce stress;
A structure installation process comprising: installing a horizontal belt at the upper and lower front portions between the thumb piles and the thumb piles; installing a curved support on the back surface of the horizontal belt to guide the steel wires located at the upper and lower portions of the earth anchor to different heights; and installing an anchor reaction belt on the front surface of the belt in the same line as the curved support;
An earth anchor tensioning process of guiding the steel wire of the above earth anchor to the curved support, passing through the horizontal belts, and introducing it into the anchor reaction zone, thereby tensioning and fixing the steel wire in the anchor reaction zone;
An excavation process that excavates the ground to the design depth;
A brace installation process for installing a brace on the thumb pile or horizontal belt during the above excavation process; and
After the excavation is completed, an underground structure is constructed, and then the thumb pile is pulled out and removed so that the thumb pile can be reused.
The above curvature support is,
A support plate formed with a high front and low back, and having a through hole formed in the center of the back surface to allow a steel wire to pass through, and installed on the back surface of the horizontal belt;
A first curved plate installed in the center of the support plate to guide the lower steel wire of the above earth anchor; and
The upper part of the support plate is installed to guide the upper steel wire of the above earth anchor, and is formed by a second curved plate having the same curvature as the first curved plate or having a different curvature.
The above thumb peg is,
A method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support, characterized in that only a portion of the detachable expanded floor plate, into which the thumb pile is inserted and joined to increase the bearing capacity by increasing the cross-sectional area on the floor surface, is point-welded to integrate it while spacing out the thumb pile, and when the thumb pile is pulled out, a blow is applied to the point welded portion to remove it, so that only the thumb pile is pulled out. delete In paragraph 1,
The above ground drilling process is,
A method for constructing a belt-type retaining wall capable of installing high-angle anchors using a curved support characterized by being perforated vertically or having a lower end having an incline of less than 20° in the excavation direction relative to the ground horizon to resist the horizontal force of earth pressure. delete delete delete

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