US20180291582A1

US20180291582A1 - Anchor having fixing device at side of pressure plate to depress land slope and method of installing same

Info

Publication number: US20180291582A1
Application number: US15/577,997
Authority: US
Inventors: Dong-Hyun Seo
Original assignee: Hyun Engineering And Construction Co ltd
Current assignee: Hyun Engineering And Construction Co ltd
Priority date: 2015-06-25
Filing date: 2016-06-23
Publication date: 2018-10-11
Also published as: CN108474192A; KR20150082152A; WO2016208990A1; KR101757975B1

Abstract

The present invention relates to an earth retaining structure for reinforcing a slope, and more particularly, to an anchor including a fixing body at a pressure plate side for compressing a slope and a method for installing the anchor in the slope. The anchor including a fixing body at a pressure plate side for compressing a slope capable of preventing tension of the anchor from being lost by installing a friction type pressure plate fixing body in a steel pipe form that is integrated with the pressure plate at the pressure plate side of the anchor, installing a primary packer at a middle part of the anchor to conduct pressurized-grouting to fix a tip end side fixing body of the anchor, compressing a large pressure plate compressing the slope by introducing a tensile force to the tension member of the anchor together with the pressure plate side fixing body, expanding a secondary packer, and conducting secondary pressurized-grouting, is provided.

Description

BACKGROUND

1. Field

The present invention relates to an earth retaining structure for reinforcing a slope, and more particularly, to an anchor including a fixing body at a pressure plate side for compressing a slope and a method for installing the anchor in the slope.

2. Description of Related Art

Generally, in civil engineering works for constructing a road, a railway, a bank, portals of a tunnel, an apartment complex, etc., a cut slope or an embankment slope often occur. In such a cut slope or an embankment slope, sliding and erosion occur. For prevent the sliding and the erosion and being in harmony with the natural environment, an environmental-friendly slope reinforcement method has been required.
A soil nailing method that has been generally performed as the slope reinforcement method has a problem in that it has a structure in which the slope is reinforced only by a frictional force of a nail, thus a larger number of nails are needed for reinforcement as compared to a structure of reinforcement using tension of an anchor.
As another slope reinforcement method, a reinforced concrete retaining wall has been mainly used. However, it is disadvantageous in that a large cost and time are required for installation of a reinforced concrete structure, thus an anchor is additionally installed while being integrated with the reinforced concrete retaining wall. However, this reinforcement method is also disadvantageous in that large costs are required for earthworks and banking works, and an entire size of a structure is also increased.
If the slope is cut, stress distribution is changed, and an underground water level is lowered such that the ground is subsidence. The phenomenon as described above occurs to a remarkable degree in a relatively soft soil and weathered rock ground. Accordingly, even when an anchor is installed at the time of excavating the slope and the slope is compressed using a large pressure plate, the pressure plate part is subsidence over time, such that a tension of the anchor is lost, as a result, there is no reinforcing effect.
Further, in a region having clear four seasons, the soil is softened due to repetition of freezing and thawing, thus the pressure plate bearing continuous compression is subsidence, as a result, the tension of the anchor is lost.

SUMMARY

An object of the present invention is to provide an anchor including a fixing body at a pressure plate side for compressing a slope capable of preventing tension of the anchor from being lost by installing a friction type fixing body in a steel pipe form that is integrated with the pressure plate at a tension side of the anchor, installing a primary packer at a middle part of the anchor to conduct pressurized-grouting to fix the fixing body at a tip end side of the anchor, compressing a large pressure plate compressing the slope by introducing a tensile force to the tension member of the anchor together with the pressure plate side fixing body at the pressure plate side, expanding a secondary packer, and conducting secondary pressurized-grouting, and a method for installing the same.
According to an aspect of the present invention, an anchor including a fixing body at a pressure plate side for compressing a slope that is configured of a tension member for introducing a tensile force by connecting the pressure plate installed to compress the slope and a tip end side fixing body fixed to an original ground by grouting, the anchor includes a primary packer installed at a middle part of the tension member to conduct primary grouting on the tip end side fixing body and fixing the tip end side fixing body, a secondary packer installed at the pressure plate side fixing body, and the pressure plate side fixing body coupled to a pressure plate compression ring configured to be fixed by secondary grouting after the secondary packer is expanded to be integrally behaved with the pressure plate capable of exhibiting a support force even at a soft ground slope.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view generally illustrating a state in which a pressure plate is compressed by an anchor including a fixing body at the pressure plate side for compressing a slope.

FIG. 2 is a view separately illustrating the fixing body of the pressure plate side.

FIG. 3 is a view illustrating a friction type tip end side fixing body of the anchor according to the present invention.

FIG. 4 is a cross-sectional view taken along line A-A′ in FIG. 1, which illustrates a position where a bag-packer is installed in a state in which a tip end side fixing body 6 is fixed by grouting and a pressure plate side fixing body 5 is installed in a drilled hole.

FIG. 5 is a cross-sectional view taken along line B-B′ in FIG. 1, which illustrates a cross section of a tension member configured of a primary injection hose 12 for first fixing the tip end side fixing body by grouting, a primary packer injection hose 11, a discharge hose 14, the tension member 9, and a secondary injection hose 13.

FIG. 6 is a cross-sectional view taken along line C-C′ in FIG. 1, which illustrates the tip end side fixing body 6.

FIG. 7 is a view illustrating a hose cutter configured to be installed at an angle of 40 to 50 degrees on a long steel rod, and formed with a sharp blade at an inner side of a steel plate of hose cutter with a hole so that the hose cutter is put into the hose and pulled, the hose is cut.

FIG. 8 is view illustrating pressure plates according to various embodiments of the present invention.

DETAILED DESCRIPTION

Hereinafter, an anchor according to the present invention will be described in detail with reference to the accompanying drawings.
Describing terms in the present invention in detail, a part fixed to the ground by grouting or bearing on a ground pressure is defined as a “fixing body”, the fixing body at a right tip end of FIG. 1 is defined as a “tip end side fixing body 6” and the fixing body having the pressure plate and a head of the left side is defined as a “pressure plate side fixing body 5”. In the present invention, the “soft ground” refers to the ground in which an exposed part of a slope is soil or a weathered rock and the pressure plate is subsidence due to a prolonged tension of the anchor.
FIGS. 1 to 8 are views generally illustrating an anchor 50 according to the present invention, in which the anchor is inserted into a drilled hole 22 and grouting is performed to compress a pressure plate 1 to a slope. Throughout the drawings, the same reference numeral denotes the same component.
FIG. 1 is a view generally illustrating the anchor 50 according to the present invention, and the anchor that is configured of a tension member 9 for introducing a tensile force by connecting a pressure plate 1 installed to compress the slope and a tip end side fixing body 6 fixed to an original ground by grouting, includes a primary packer 7 installed at a middle part of the tension member 9 to conduct primary grouting on the tip end side fixing body 6 and fixing the tip end side fixing body, a secondary packer 8 installed at the pressure plate side fixing body 5, and the pressure plate side fixing body coupled to a pressure plate compression ring 4 configured to be fixed by secondary grouting after the secondary packer 8 is expanded to be integrally behaved with the pressure plate 1 capable of exhibiting a support force even at a soft ground slope.
The anchor 50 according to the present invention includes the tension member 9 having a length longer than a length of the drilled hole 22 and a thickness of the pressure plate 1, an anchor head 2 and a tip end side anchor head 15 formed at both ends of the tension member 9, an anchor cap 3 covering the anchor head 2, the pressure plate 1 compressing the slope at a left side of the tension member 9, the pressure plate side fixing body 5 coupled to the pressure plate compression ring 4 that is fitted into the hole 19 of the pressure plate 1 by welding or using a coupling means such as a screw, the tip end side fixing body 6 positioned opposite to the pressure plate side fixing body 5, the primary packer 7 positioned at the middle part of the tension member 9, two shrinkable tubes 10 fitted on the tension member 9 and positioned at both sides of the primary packer 7 while being spaced apart from the primary packer 7 by a predetermined distance, the secondary packer 8 installed at the pressure plate side, a secondary injection hose 13 installed in the anchor 50, a primary packer injection hose 11 extending over the tip end side fixing body 6 through the pressure plate side fixing body 5, a primary injection hose 12, a discharge hose 14, a secondary packer injection hose 16, a temporary packer blocking the pressure plate compression ring at the time of secondary grouting, and a hose cutter 21 for cutting the primary injection hose 12.
The tension member 9 is formed of a single wire or a plurality of wires, and is coated with a PE tube 24 so that it is smoothly elongated at the time of extension after cement grouting, thereby preventing an injecting grouting material is not attached. In the present specification, a case in which the tension member 9 formed of four groups is installed is illustrated.
The pressure plate side fixing body 5 of FIG. 2 is configured to be integrally behaved when the pressure plate compression ring 4 in a flange form is coupled to a tip end of a steel pipe 18 by welding or using a coupling means such as a screw, and the pressure plate compression ring 4 coupled to the hole 19 of the pressure plate and the fixing body in the steel pipe form extend the tension member 9 using the anchor head 2. At this time, the pressure plate compression ring 4 need not necessarily have a circular shape, but may have various shapes such as a tetragonal shape, a hexagonal shape, and the like.
The steel pipe 18 of the pressure plate side fixing body 5 is configured to have uneven parts formed at an outer surface thereof and have large friction force by grouting, a steel pipe hole 17 is formed in the tip end side of the steel pipe from the secondary packer 8 so that the injecting grouting material in the inside is also injected to the outside of the steel pipe at the time of grouting, the secondary packer 8 has a bag-packer form, is formed on the outside of an imperforate steel pipe part, and is provided with the secondary packer injection hose and a secondary discharge hose penetrating through the packer, and the primary injection hose and the primary packer injection hose penetrate therethrough to be additionally installed. In a more preferable embodiment, in order to prevent leakage of the secondary packer, the pressure plate side fixing body 5 is configured so that the primary injection hose 12 through which the primary injection is completed and the primary packer injection hose 11 are cut by the hose cutter 21 at a depth of about 2 m of the drilled hole, and only the secondary packer is installed.
The tip end side fixing body 6 of FIG. 3 is a friction type fixing body, and the tip end side anchor head 15 serves to fix the tension member 9. As a fixing body outside the tension member 9, various types of fixing body such as a bearing type, a combination type of the bearing type and the friction type, and the like may be applied.
FIG. 4 is a cross-sectional view taken along line A-A′ in FIG. 1, which illustrates a position where the secondary bag-packer is mounted in a state in which the tip end side fixing body 6 is fixed by grouting and the pressure plate side fixing body 5 is installed in the drilled hole 22.
FIG. 5 is a cross-sectional view taken along line B-B′ in FIG. 1, which illustrates a cross section of the tension member configured of the primary bag-packer, the primary injection hose 12 for first fixing the tip end side fixing body 6 by grouting, the primary packer injection hose 11, the discharge hose 14, the tension member 9, and the secondary injection hose 13.
FIG. 6 is a cross-sectional view taken along line C-C′ in FIG. 1, which illustrates the tip end side fixing body 6.
FIG. 7 illustrates the hose cutter 21 that is configured to be installed at an angle of 40 to 50 degrees, preferably, 45 degrees on a long steel rod 23, and formed with a sharp blade at an inner side of a steel plate of hose cutter with a hole so that when the injection hoses 11 and 12 or the discharge hose 14 is put into the hole of the hose cutter and pulled, the injection hoses 11 and 12 or the discharge hose 14 is cut. The hose cutter 21 is used at the time of cutting the injection hoses 11 and 12, and the discharge hose 14 in the drilled hole 22.
FIG. 8 is view illustrating pressure plates having various shapes such as a cross shape, a tetragonal shape, etc., and cross-shaped pressure plates 1 may be connected to each other to form a lattice form.
The anchor which is configured of the tension member 9 for introducing a tensile force by connecting the pressure plate 1 installed to compress the slope and the tip end side fixing body 6 fixed to the original ground by grouting, includes the primary packer 7 installed at a middle part of the tension member 9 to conduct primary grouting on the tip end side fixing body 6 and fixing the tip end side fixing body 6, the secondary packer 8 installed at the pressure plate side fixing body 5, and the pressure plate side fixing body 5 coupled to the pressure plate compression ring 4 configured to be fixed by secondary grouting after the secondary packer 8 is expanded to be integrally behaved with the pressure plate 1 capable of exhibiting a support force even at a soft ground slope.
As the main technical idea and characteristics of the present invention, if the slope is cut, restrained stress is released to change stress distribution, and an underground water level is lowered, such that plastic deformation of the soft ground occurs. The phenomenon as described above occurs to a remarkable degree in a relatively soft soil and weathered rock ground. Accordingly, even when the anchor 50 is installed at the time of excavating the slope and the slope is compressed using the large pressure plate 1, the pressure plate 1 part is subsidence over time, such that a tension of the anchor 50 is lost, as a result, there is no reinforcing effect.
Further, in a region having clear four seasons, the soil is softened due to repetition of freezing and thawing, thus the pressure plate 1 bearing continuous compression is subsidence, as a result, the tension of the anchor 50 is lost.
In order to solve the above problems, the friction type pressure plate side fixing body 5 in a steep pipe form integrated with the pressure plate is installed at the tension side of the anchor 50, thereby preventing loss of tension of the anchor 50.
Further, the primary packer is installed at a middle part of the anchor 50 to conduct pressurized-grouting to fix the fixing body 6 at the tip end side of the anchor, the large pressure plate 1 compressing the slope is compressed by introducing a tensile force to the tension member 9 of the anchor together with the pressure plate side fixing body, the secondary packer 8 is expanded, and the secondary pressurized-grouting is conducted, thereby completing the process.
According to a preferred embodiment of the present invention, a method for installing an anchor includes: forming a drilled hole 22 in a slope of the soft ground such as soil and weathered rock, inserting the anchor 50 in which a tip end side fixing body 6 and a tension member 9 are coupled, and then conducting grouting up to a part where a primary packer 7 is installed at a middle part of the anchor 50 for grouting of the tip end side fixing body 6 of the anchor; installing a pressure plate 1 on a tension member 9 of the anchor and fitting a pressure plate side fixing body 5 to which a pressure plate compression ring 4 is coupled on the tension member 9 to be inserted and installed in the drilled hole 22; expanding a secondary packer 8 installed at a tip end of the pressure plate side fixing body 5; installing an anchor head 2 on the pressure plate 1 and extending the tension member 9; and conducting secondary grouting.
Considering site conditions, according to a second embodiment of the present invention, a method for installing an anchor includes: inserting an anchor 50 in which a tip end side fixing body 6, a tension member 9, and a pressure plate side fixing body 5 are integrally assembled into a drilled hole 22 in a slope, and expanding a packer to conduct grouting; fitting a pressure plate 1 on the pressure plate side fixing body 5 and then screw-coupling a pressure plate compression ring to be fastened; and extending and fixing a tension member 9 of the anchor that protrudes from a pressure plate hole 19 using an anchor head 2.
The pressure plate side fixing body 5 is configured to be integrally behaved when the pressure plate compression ring 4 in a flange form is coupled to a tip end of a steel pipe by welding or using a screw, and the pressure plate compression ring 4 coupled to the pressure plate hole and the pressure plate side fixing body 5 in the steel pipe form extend the tension member 9 by a hydraulic jack using the anchor head 2.
The steel pipe 18 of the pressure plate side fixing body 5 is configured to have uneven parts formed at an outer surface thereof and have large friction force by grouting, a steel pipe hole 17 is formed in the tip end side of the steel pipe 18 from the packer so that the injection material in the inside is also injected to the outside of the steel pipe 18 at the time of grouting, the secondary packer 8 has a bag-packer form, is formed on the outside of an imperforate steel pipe part, and is provided with a secondary packer injection hose 16 and a secondary discharge hose penetrating through the packer, and a primary injection hose 12 and a primary packer injection hose 11 penetrate therethrough to be installed. In a more preferable embodiment, in order to prevent leakage of the packer, the primary injection hose 12 through which the primary injection is completed and the primary packer injection hose 11 are cut by a hose cutter 21 at a depth of about 2 m of the drilled hole 22. By cutting the hoses as described above, the primary packer injection hose 11 and the primary injection hose 12 do not penetrate through the secondary packer 8, the secondary packer 8 is simply configured and may be easily installed. At the time of secondary grouting, the discharge hose is not needed, and a temporary packer is installed at the pressure plate compression ring of the pressure plate side fixing body 5 to inject a grout solution. At the time of secondary injection, in a case of the ground in which the pressure plate 1 and the slope are compressed closely, the secondary packer 8 may be omitted.
As the tip end side fixing body 6, various existing fixing bodies may be used. In FIG. 3, the tip end side fixing body 6 of the anchor 50 is a friction type fixing body, and the tip end side anchor head 15 serves to fix the tension member 9. As a fixing body 20 outside the tension member coupled to the anchor head 2, various types of fixing body such as a bearing type, a combination type of the bearing type and the friction type, and the like may be applied.
In designing the anchor, a support ability of the pressure plate and the pressure plate side fixing body needs to be larger than a tensile load of the tension member, and a support ability of the tip end side fixing body also needs to be larger than the load introduced to the tension member.
According to the present invention, the friction type pressure plate side fixing body in a steel pipe form that is integrated with the pressure plate and behaved integrally at the pressure plate side of the anchor, are installed deeper than the freezing depth, such that it is possible to prevent the settlement caused by the phenomenon that the soil is softened due to repetition of freezing and thawing occurring in the region having clear four seasons.
Even in the soft ground that may not bear the bearing pressure of the pressure plate, the friction type pressure plate side fixing body in a steel pipe form may reinforce the support force for the soft ground by a frictional force.
The friction type pressure plate side fixing body in a steel pipe form that is integrated with the pressure plate are installed deeper than the effect zone from the slope, such that it is possible to prevent additional settlement of the pressure plate bearing continuous compression and loss of tension of the anchor, in spite of the lowering of the underground water level and the change in stress.
Further, the pressure plate side fixing body has the same effect as the nailing, and since the pressure plate is fixed to the friction type pressure plate side fixing body in a steel pipe form, deformation of a tensile force does not occur, and it is possible to safely perform extension even when there is a need to perform extension again.

DESCRIPTION OF REFERENCE NUMERALS

1 pressure plate
2 anchor head
3 anchor cap
4 pressure plate compression ring
5 pressure plate side fixing body
6 tip end side fixing body
7 primary packer
8 secondary packer
9 tension member
10 shrinkable tube
11 primary packer injection hose
12 primary injection hose
13 secondary injection hose
14 discharge hose
15 tip end side anchor head
16 secondary packer injection hose
17 steel pipe hole
18 steel pipe
19 pressure plate hole
20 fixing body
21 hose cutter
22 drilled hole
23 long steel rod
24 PE pipe
50 anchor

Claims

What is claimed is:

1. An anchor including a fixing body at a pressure plate side for compressing a slope, and configured of a tension member for introducing a tensile force by connecting a pressure plate installed to compress the slope and a tip end side fixing body fixed to an original ground by grouting, the anchor comprising:

a primary packer installed at a middle part of the tension member to first conduct primary grouting on the tip end side fixing body and fixing the tip end side fixing body; and

the pressure plate side fixing body coupled to a pressure plate compression ring configured to be fixed by secondary grouting after the secondary packer is expanded to be integrally behaved with the pressure plate exhibiting a support force even at a soft ground slope.

2. The anchor of claim 1, wherein in a steel pipe of the pressure plate side fixing body, a steel pipe hole is formed in a tip end side of the steel pipe from the secondary packer so that an injection material in the inside of the steel pipe is also injected to the outside of the steel pipe at the time of grouting.

3. A method for installing an anchor including a fixing body at a pressure plate side for compressing a slope, the method comprising:

forming a drilled hole in a slope of a soft ground, inserting the anchor in which a tip end side fixing body and a tension member are coupled, and then expanding a primary packer at a middle part of the anchor for grouting of the tip end side fixing body of the anchor and conducting grouting up to a part where the primary packer is installed;

installing a pressure plate on the tension member of the anchor and fitting the pressure plate side fixing body to which a pressure plate compression ring is coupled on the tension member to be inserted and installed in the drilled hole;

expanding a secondary packer installed at a tip end of the pressure plate side fixing body;

installing an anchor head on the pressure plate and extending the tension member; and

conducting secondary grouting on the pressure plate side fixing body.

4. A method for installing an anchor including a fixing body at a pressure plate side for compressing a slope, the method comprising:

inserting the anchor in which a tip end side fixing body, a tension member, and the pressure plate side fixing body are integrally assembled into a drilled hole in a slope, and expanding a primary packer to conduct grouting;

fitting a pressure plate on the pressure plate side fixing body and then screw-coupling a pressure plate compression ring to be fastened; and

extending and fixing the tension member of the anchor that protrudes from a pressure plate hole using an anchor head, and covering with an anchor cap; and

conducting secondary grouting on the pressure plate side fixing body.