WO2002048467A1

WO2002048467A1 - Geogrid

Info

Publication number: WO2002048467A1
Application number: PCT/KR2001/002069
Authority: WO
Inventors: Sung-Min Hong
Original assignee: Gong, Hak-Bong; Lee, Seung-Hoon
Priority date: 2000-12-12
Filing date: 2001-11-30
Publication date: 2002-06-20
Also published as: US20020069605A1; AU2002221171A1

Abstract

Disclosed is a geogrid (1) comprising a sheet main body (3) formed with a plurality of through holes (5) through which soil passes; at least one connector (7) protruded from a surface of the sheet main body (3); and at least one accepter (13) positioned opposite the connector (7) and accepting the connector (7) of another geogrid (1). With this configuration, the geogrid (1) can be conveniently, carried, maintained and constructed, and is improved in durability.

Description

GEOGRI D

FIELD OF THE INVENTION

The present invention relates in general to a geogrid buried in reinforced soil of a slope or a retaining wall. BACKGROUND ART

Generally, a geogrid is buried in soil which is piled or back-filled onto a slope or a retaining wall, to thereby prevent soil from falling and collapsing due to earth pressure generated from the slope or the retaining wall.

Conventionally, a geogrid has been widely used, which is of a net type. The geogrid is classified into a sheet type and a woven type. The sheet type geogrid is made by extruding high molecular polyethylene and polypropylene into a sheet form, forming a multiplicity of holes on it vertically and horizontally, and by mechanically stretching each space between the holes. On the other hand, the fabric cloth type geogrid is made by weaving a polyester fiber in a lattice form with wefts and warps, and coating it with PVC (polyvinyl chloride) . The conventional geogrid has been produced to have several meters of width and several ten meters of length, and supplied to a user after being rolled. Therefore, in order to install the geogrid into the slope or the retaining wall, a user has to cut the geogrid in consideration of the size of the slope or the retaining wall . However, because the conventional roll-typed geogrid ought to be cut into a predetermined size on the spot in consideration of the size of the slope or the retaining wall, not only it is not convenient to carry, maintain and construct the geogrid but also the durability thereof is poor owing to a hydrolysis at a cutting part in which the coating comes off.

DISCLOSURE OF INVENTION

Accordingly, the present invention has been made keeping in mind the above-described shortcoming and user' s need, and an object of the present invention is to provide a geogrid which can be conveniently carried, maintained and constructed, and is improved in durability.

This and other objects of the present invention may be accomplished by the provision of a geogrid comprising a sheet main body formed with a plurality of through holes through which soil passes; at least one connector protruded from a surface of the sheet main body; and at least one accepter positioned opposite the connector and accepting the connector of another geogrid.

Herein, the connector is provided one end part of the sheet main body, and the accepter is provided the other end part of the sheet main body opposite the connector, thereby decreasing an overlap of the geogrids . Further, on at least one surface of the sheet main body is provided a rib which is protruded in a direction perpendicular to a coupling direction of the geogrid, thereby increase the tensile strength of the geogrid 1 and the friction between soil and the geogrid 1.

Further, the accepters are communicated with or partitioned off from the through holes arranged adjacent to the end part of the sheet main body.

Further, each connector is comprised of a pin part being accepted to each accepter of another geogrid, and a head part extended at the free end of the pin part; and the width of the head part is respectively larger and smaller than minimum widths of the accepter and the through hole, thereby preventing the geogrids from a vertical breakaway. Further, the width of the head part may be smaller than minimum width of the accepter, thereby facilitating coupling with another geogrid.

Preferably, each accepter has one of circular, elliptical, elongated, and polygonal shapes.

Preferably, the sheet main body and the connectors are made from metallic material, and then the connectors are welded to the sheet main body, or the sheet main body and the connectors are made from a synthetic resin as one body.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be better understood and its various objects and advantages will be more fully appreciated from the following description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view of a geogrid according to a first embodiment of the present invention;

Fig. 2 is an enlarged perspective view of a main part of Fig. 1; Fig. 3 is a sectional view of Fig. 2 taken along line III-III;

Fig. 4 is a perspective view showing a state in which the geogrids of Fig. 1 are coupled each other;

Fig. 5 is a perspective view of a geogrid according to a second embodiment of the present invention;

Fig. 6 is an enlarged perspective view of a main part of Fig. 5;

Fig. 7 is a sectional view of Fig. 6 taken along line VII-VII; Fig. 8 is a perspective view showing a state in which the geogrids of Fig. 5 are coupled each other;

Fig. 9 is a perspective view showing a state in which the geogrids according to the first embodiment of the present invention are combined to blocks of a retaining wall;

Fig. 10 is a perspective view showing a method of combining the geogrids to the blocks of the retaining wall; and

Fig. 11 is a sectional view showing a state in which the geogrids according to the first embodiment of the present invention are combined to the blocks of the retaining wall in a multi-layer structure. MODES FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings, and the same configuration has the same number.

To describe the preferred embodiments referring to the drawings, the same elements will be given the same numbers, and repetitive descriptions will be avoided as necessary. As shown in Figs. 1 through 3, a geogrid according to a first embodiment of the present invention comprises a sheet main body 3 on which a plurality of through holes 5 are provided for allowing soil to pass therethrough, a plurality of connectors 7 protruded at one end part of the sheet main body 3, and a plurality of accepters 13 positioned at an opposite end part of the sheet main body 3 and accepting the connectors 7 of the adjacent geogrid 1.

The sheet main body 3 has a predetermined thickness and a predetermined area, and is of a rectangular shape. Herein, the sheet main body 3 may be one of a square shape, a polygonal shape, etc. It is desirable that the thickness thereof ranges from 2mm to 6mm and the area thereof ranges from 0.5m² to 1.5m², and these thickness and area may change according to the material of the sheet main body 3. It is desirable that the material of the sheet main body 3 has the properties of low elongation and chemical durability in order to distribute pressure of soil and to strengthen binding and supporting forces which act onto the slope or the retaining wall, and thus a synthetic resin containing a glass fiber or metal is employed as the sheet main body 3. Particularly, in the case of metal, it is desirable that a surface of the metal is plated or coated for preventing corrosion, to thereby improve the chemical durability. Further, the metal is desirable to be one of aluminum, cast iron and stainless steel. On the sheet main body 3 is provided the plurality of through holes 5 vertically and horizontally arranged at equal intervals. Every through hole 5 is of an elongated shape. The functions of the through hole 5 are to distribute the pressure of the soil by being contacted with the soil on and beneath the sheet main body 3, and to increase the friction between the soil and the sheet main body 3. The friction therebetween varies according to the size and number of the through holes 5. Therefore, the size and number of the through holes 5 is determined to have predetermined tensile strength of the sheet main body 3, and it is desirable that total area of the through hole 5 occupies 60% ~ 70% of total area of the sheet main body 3. Herein, the through hole 5 may be of a circular, elliptical or polygonal shape, instead of the elongated shape. Further, the through holes 5 may be alternately arranged on the sheet main body 3. On the other hand, on one end part of the sheet main body 3, that is, inside one edge of the sheet main body 3 is provided the plurality of connectors 7 protruded from a surface of the sheet main body 3. The connectors 7 are arranged at predetermined intervals along the end part. Every connector 7 is comprised of a pin part 9 being accepted to the accepter 13 of another geogrid 1, and a head part 11 radially extended at the free end of the pin part 9. The pin part 9 and the head part 11 have a circular sections, respectively. Further, the diameter of the pin part 9 is smaller than the minimum width of the accepter 13, and the diameter of the head part 11 is respectively larger and smaller than the minimum width of the accepter 13 and the minimum width of the through hole 5. Further, the length of the pin part 9, that is, the height of the pin part 9 from the surface of the sheet main body 3 to the bottom surface of the head part 11 is bigger than the thickness of the sheet main body 3. Further, the size and number of the connectors 7 is determined to have predetermined tensile strength against the pressure of soil, and it is desirable that the connectors 7 is made from the same material as that of the sheet main body 3. Therefore, the connector 7 and the sheet main body 3 may be produced in one body by means of injection molding in the case that these are made from the synthetic resin material containing the glass fiber, whereas the connector 7 and the sheet main body 3 may be ^'produced in one body by means of welding or casting in the case that these are made from the metallic material. Herein, the cross section of the pin part 9 may be of an elliptical shape, a polygonal shape, or etc., instead of the circular shape.

Further, on the opposite end part to the end part on which the connectors 7 are provided, that is, inside the other edge of the sheet main body 3 is provided the plurality of accepters 13. The accepters 13, each having a slot shape, are respectively communicated with the through holes 5 arranged adjacent to the end part. In a part that the through hole 5 and the accepter 13 are joined is chamfered so as to help the pin part 9 of the connector 7 to move from the through hole 5 to the accepter 13. Further, the minimum width of the accepter 13 is larger and smaller than the diameter of the pin part 9 and the head part 11, respectively. Herein, the accepter 13 may be of a circular shape, an elliptical shape, a polygonal shape, or etc., instead of the slot shape. With this configuration, as shown in Fig. 4, a pair of geogrids 1 of the same configuration are coupled by inserting the connector 7 of one geogrid 1 into the accepter 13 of another geogrid 1 through the through hole 5, so that the geogrids 1 stand in line and are prevented from a horizontal and vertical breakaway.

Herein, in order to increase the tensile strength of the geogrid 1 and the friction between soil and the geogrid 1, on at least one side of the sheet main body 3 may be provided a plurality of ribs (refer to ribs 15 in Fig. 5) which are protruded from the surface thereof and arranged in a direction perpendicular to a coupling direction. Further, every accepter 13 may be partitioned off from the through hole 5 arranged along the end part of the sheet main body 3.

As shown in Figs. 5 through 7, unlike the above- described geogrid 1, a geogrid 1 according to a second embodiment of the present invention comprises the plurality of ribs 15 which are protruded from the bottom surface thereof and arranged in a direction perpendicular to a coupling direction, so as to increase the tensile strength of the geogrid 1 and the friction between soil and the geogrid 1. However, the rib 15 is not formed on the bottom surface of one end part of a sheet main body 3 on which connectors 7 are provided, in order to facilitate piling up the geogrids 1 when the geogrids 1 are stored. Further, each connector 7 provided on one end part of the sheet main body 3 is comprised of a pin part 9 being accepted to an acceptor 13, and a head part 11 extended and bent from a free end of the pin part 9. Preferably, the pin part 9 and the head part 11 have rectangular sections, respectively. The length of the head part 11 is smaller than that of the accepter 13, and the width thereof is smaller than that of the accepter 13. An outer part in which the pin part 9 and the head part 11 are joined is chamfered in order to facilitate coupling with another geogrid 1. Further, the inside height of the pin part 9 protruded from the surface of the sheet main body 3 is bigger than the thickness sum of the sheet main body 3 and the rib 15.

Every accepter 13 is partitioned off from every through hole 5 arranged adjacent to the other end part of the sheet main body 3, and is arranged at predetermined intervals along the end part. Each accepter 13 has a rectangular shape, and has a length and a width larger than those of the connector 7. Further, each accepter 13 has the same width as that of the through hole 5. With this configuration, as shown in Fig. 8, a pair of geogrids 1 of the same configuration are coupled by inserting the connectors 7 of one geogrid 1 into the accepters 13 of another geogrid 1, so that the geogrids 1 stand in line and are prevented from a horizontal and vertical breakaway. Moreover, the friction between the geogrid 1 and soil is increased by the plurality of ribs 15 provided on the reverse side of the sheet main body 3. Herein, the connectors 7 of one geogrid 1 are inserted into the through holes 5 arranged along the end part of the sheet main body 3, without being inserted into the accepters 13 of another geogrid 1. Furthermore, without the accepters 13, the through holes 5 arranged along the end part of the sheet main body 3 can be employed as the accepters 13 in which the connectors 7 are inserted. Further, on both surfaces of the sheet main body 3 may be provided the plurality of ribs 15 to be arranged in a direction perpendicular to a coupling direction. Further, the through hole 5 may be of a circular, elliptical or polygonal shape, instead of the rectangular shape. With reference to Figs. 9 through 11, the process of constructing the geogrid 1 according to first embodiment of the present invention onto a retaining wall built by a plurality of blocks 21 and fixing pins 27 will be described hereinbelow. First, in the course of building the retaining wall by piling up the plurality of blocks 21 with the plurality of fixing pins 27, when the retaining wall has a predetermined height, onto the rear of the piled blocks 21 is back-filled with soil. After back-filling soil, the accepters 13 of the geogrid 1 are deposited on the block 21, and pin parts 29 of the fixing pins 27 are inserted into fixing pin accepters 23 through the accepters 13 of the geogrid 1, thereby fixing one end of the geogrid 1 on the block 21 by means of the fixing pin 27. Then, the accepters 13 of another geogrid 1 can be additionally coupled to the connectors 7 of the geogrid 1 fixed on the block 21, in consideration of subsidence of ground, and the area and the pressure of the back-filled soil. That is, the geogrid 1 buried in the soil can be extended with a predetermined length by coupling the plurality of geogrids 1 in line.

Thereafter, a pinhead part 31 of the fixing pin 27 is inserted a pinhead accommodating part 25 formed beneath the block 21, and a plurality of blocks 21 is newly piled up with a predetermined height thereon. At this time, onto the rear of the block 21 is back-filled with the soil so as to keep the geogrid 1 combined to the block 21 horizontally.

Lastly, as shown in Fig. 11, in consideration of subsidence of ground, the a'rea and the pressure of the back-filled soil, and the height of the retaining wall, the plurality of geogrids 1 are combined to the block 21 by arranging along the piling direction of the blocks 21 at a predetermined interval and are coupled to other geogrids 1 in line, and onto the rear of the block 21 is back-filled with the soil, thereby completing the retaining wall. Hence, to the geogrid 1 buried in soil generated from the friction by the soil filled up the through holes 5 thereof and contacted with the upper and lower surfaces of the sheet main body 3. Thus, the pressure of the backfilled soil is distributed by the tensile force of the geogrid 1 and by the friction due to the soil. According as the block 21 forming the retaining wall is supported by the friction of the geogrid 1, the movement thereof is prevented and the pressure of the back-filled soil is distributed, so that the retaining wall gets stability.

As described above, by standardizing a geogrid with a predetermined size, not only it is easy to carry, maintain and construct the geogrid. Further, a user do not have to cut the geogrid on the spot, thereby preventing the hydrolysis at a cutting part and improving the durability thereof. In the above-described embodiment, the geogrid according to the present invention is applied to the retaining wall. However, the geogrid may be buried in a slope at the front, the rear, the right, and the left thereof, so as to distribute the pressure of the slope, thereby preventing soil from falling and collapsing.

Further, in the above embodiments, one end part of one geogrid is coupled to the other end part of another geogrid in line. However, one end part of the geogrid may be coupled to the middle part of another geogrid in line, as necessary.

As described above, the present invention provides a geogrid which can be easily carried, maintained and constructed, and is improved in durability by standardizing it with a predetermined size. Although the preferred embodiments of the present invention have been disclosed for illustrative purpose, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

WHAT IS CLAIMED IS:

1. A geogrid comprising: a sheet main body formed with a plurality of through holes through which soil passes; at least one connector protruded from a surface of the sheet main body; and at least one accepter positioned opposite the connector and accepting the connector of another geogrid.

2. The geogrid according to claim 1, wherein the connector is provided one end part of the sheet main body, and the accepter is provided the other end part of the sheet main body opposite the connector.

3. The geogrid according to claim 2, wherein on at least one surface of the sheet main body is provided a rib which is protruded in a direction perpendicular to a coupling direction of the geogrid.

4. The geogrid according to claim 3, wherein the accepters are communicated with the through holes arranged adjacent to the end part of the sheet main body.

5. The geogrid according to claim 3, wherein the accepters are partitioned off from the through holes arranged adjacent to the end part of the sheet main body.

6. The geogrid according to claim 4, wherein each connector is comprised of a pin part being accepted to each accepter of another geogrid, and a head part extended at the free end of the pin part; and the width of the head part is larger and smaller than minimum widths of the accepter and the through hole, respectively.

7. The geogrid according to claim 5, wherein each connector is comprised of a pin part being accepted to each accepter of another geogrid, and a head part extended at the free end of the pin part; and the width of the head part is larger and smaller than minimum widths of the accepter and the through hole, respectively.

8. The geogrid according to claim 4, wherein each connector is comprised of a pin part being accepted to each accepter of another geogrid, and a head part extended at the free end of the pin part; and the width of the head part is smaller than minimum width of the accepter.

9. The geogrid according to claim 5, wherein each connector is comprised of a pin part being accepted to each accepter of another geogrid, and a head part extended at the free end of the pin part; and the width of the head part is smaller than minimum width of the accepter.

10. The geogrid according to claim 6, wherein each accepter has one of circular, elliptical, elongated, and polygonal shapes.

11. The geogrid according to claim 7, wherein each accepter has one of circular, elliptical, elongated, and polygonal shapes.

12. The geogrid according to claim 8, wherein the accepter has one of circular, elliptical, elongated, and polygonal shapes.

13. The geogrid according to claim 9, wherein the accepter has one of circular, elliptical, elongated hole, and polygonal shapes.

14. The geogrid according to claim 2, wherein the sheet main body and the connectors are made from metallic material, and the connectors are welded to the sheet main body.

15. The geogrid according to claim 2, wherein the sheet main body and the connectors are made from a synthetic resin as one body.