슬라이드 제목 없음 - Geosynthetica

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Chonnam National University

Dept. of Textile Eng.

GEOSYNTHETICS TECHNOLOGY

TRANSFER

FROM A KOREAN PERSPECTIVE

Han-Yong, Jeon, Ph.D.

GSRL(G

eo

S

ynthetics

R

esearch

L

aboratory

)

Department of Textile Engineering

Faculty of Applied Chemistry

Chonnam National University, Kwangju, Korea

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

INTRODUCTION

Geosynthetics industry in Korea

- Promising field for investment and development

Many types of domestic geosynthetic products

- To be produced and their applications widely enlarged every year

Types of geosynthetics

- Geotextiles, geomembranes, geogrids, PDB(plastic drain board), geocomposites, GCLs(geosynthetic clay liners) etc.

• Application fields of geosynthetics

- Soft soil reinforcement, soil retaining walls, waste landfills, road and subway construction, tunnel and earth dam construction etc.

Technologies relating to Korean geosynthetics

- To be come mainly from U.S.A., Europe and Japan etc.

In this paper - The recent technology circumstances of Korean geosynthetics

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

FACTORS AFFECTING THE POTENTIAL GROWTH

OF GEOSYNTHETICS

Cultural

Traditional geotechnical and civil engineering structures

- Long histories in Korea/no evidence about geosynthetics

Woven geotextiles as protection materials in the breakwater construction

- A-San and Nam-Yang areas for the first time in 1971

Geotextiles used as asphalt overlay materials

- Highway construction between Seoul

Pusan/Sunchun

Pusan

Many types of geosynthetics

- To be increased every year and new materials have been developed since 1996

Geosynthetic related construction

- Less familiar with that of traditional civil engineering fields

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

Economic

• Korea economy

- Economic crisis under IMF control, 1998

Gradually recovering since the second half of 1999

• During the economic crisis

- Many large, middle and small construction companies to be bankrupt

- Many agencies to import foreign geosynthetics to be limited because of the rising trend of U.S. dollar rate

• Currently, Korean economy

- To be recovering since the second half of 1999

- Demands for geosynthetics : to be increasing gradually

- Imported geosynthetics from the USA and Europe to be slightly increasing at a uniform rate

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

Developmental

Table. Present State of Geosynthetics in Korea

Geosynthetics

Geotextile (woven)

Geotextile (nonwoven)

Geogrid (GG)

Geomembrane (GM)

GCLs

PDB

Geonet composite (GC)

Geopipe (GP)

Geofoam

Sheet drain(SD)

Miscellaneous

Raw Materials

PP, PET

PP, PET polyester, glass fiber

HDPE, EVA

GT/bentonite/GT or GM

GT/PP core

GT/GN/GT

HDPE

PS

GT/PE Core various

Number of Manufacturers

6

10

8

3

2

3

4

2

4

1

3

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

core

Current Resins or Materials

• Geotextiles – Polypropylene or polyester

• Geomembranes – HDPE (high density polyethylene), EVA (ethylene vinyl acetate)

• Geogrids – High tenacity polyester or glass fiber

• GCLs – Nonwoven/bentonite/woven or nonwoven geotextile, bentonite/HDPE geomembrane composite

• PDB – Spunbonded nonwoven geotextile filter covering a polypropylene drainage

• Geonet composite – Nonwoven geotextile/geonet/nonwoven geotextile

• Geopipe – HDPE pipe (smooth and corrugated)

• Geofoam – Expanded polystyrene

• Sheet drain – Nonwoven geotextile/various drainage cores

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

[ Geosynthetic Products ]

• Geotextiles

Nonwovens of staple fibers : Width ~8.6m, weight ~3500g/m 2

- Spunbonded nonwovens of filament fibers : ~600g/m 2

Woven geotextiles of split polyester and polypropylene yarns

: Design strength is 4~50 ton/m.

• Geomembranes

HDPE smooth type geomembranes : Thickness 1.0~2.0 mm

- Textured geomembranes : In progress

• Geogrids

Fabric type geogrids : high tenacity polyester yarns

: PVC or acrylic resin - coating agent

* In 1999 - glass fiber geogrids : In progress.

: Reinforcement materials in road construction

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

• GCLs

Nonwoven / bentonite / woven or nonwoven type

Bentonite + adhesive / HDPE geomembrane type

Specially designed GCLs to prevent the bentonite loss

- Powder and granular type bentonites

: To be imported from USA, Russia, China and Australia etc.

- As a composite liner for waste landfills

- As waterproofing materials in tunnels and subway construction

• Miscellaneous

Geofoam , geopipe and geosynthetic sheet drains etc.

: for special end uses in construction

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

Regulatory

• Regulations of geosynthetics

- To be supervised by different ministries of the government

Ministry of Environment - G eosynthetics for waste landfills

Ministry of Construction & Transportation - G eosynthetics for general construction

Korea Highway Corporation - G eosynthetics for transportation

• Korean standards of industry

- JIS, ISO and ASTM standards etc.

• Geosynthetics

- GRI Standard Test Methods, ASTM, ISO etc. from 1998

• Test methods and regulations of geosynthetics in Korea

- To be influenced by special task forces in different installation fields

- Many regulatory standards to be adopted for different installation fields on the project-specific basis

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

TRAINING, EDUCATION, SEMINARS, CONFERENCES

Training and education programs in geosynthetics evaluation, installations, case histories, etc.

The supervising organizations for geosynthetic related seminars and conferences in

Korea

- To be supervised by the Korean Geotechnical Society from 1987 to 2000

- The Korean Geosynthetic Society (KGSS) from 2001

- To be focused to design and installation rather than manufacturing and testing

- Three to four seminars and conferences on geosynthetics per year

: For seminars - Special title to be related in geosynthetic installation

: For conferences - Special divisions

Geosynthetics manufacturing, testing and

Korean Geotechnical Society

– Division of Geosynthetics

Korean Geosynthetic Society(KGSS)

FITI : GSI-Korea

GS-ATRA (GeoSynthetic Application Technology Association)

Geosynthetics Research Committee of KOSEF (Korea Science and Engineering

Chonnam National University

Dept. of Textile Eng.

LESSONS LEARNED FROM FORENSIC ANALYSIS OF

CASE HISTORIES APPLICABLE TO SPECIFIC AREAS

Environmental

• Most waste landfills

- Steep slopes and many rough stones in the canyon landfills

- The problems for applications as following :

Failure of geomembranes due to the imperfect seaming

Destruction of waste landfill system and pollution of surrounded soils

Degradation of polypropylene nonwoven geotextiles due to UV attack

Decrease of tensile strength and elongation

Bentonite loss from GCLs etc.

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

Geotechnical

• Applications of geogrids

Soil retaining wall

Many reduction factors to be influenced the long-term strength

Specifically high reduction factors to be adopted

No considerations of reduction factors for high rainfalls and drainage systems

Transportation

• Application of geosynthetics as reinforcement materials

Soft soil reinforcement and road construction field

Woven geotextiles of high tensile stresses

Glass fiber geogrids : protection the failure by differential settlement

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

KOREAN RESEARCH AND DEVELOPMENT VERSUS

INTERNATIONAL NEEDS

Research topics and interests to geosynthetics

- Worldwide information, data, technical papers, etc. on geosynthetics

Main research fields involving geosynthetics

- Soil retaining walls, waste landfills, roads, railroads and runway, soft soil reinforcement etc.

Research on geosynthetic regulations and standardization

- GSRL (Geosynthetic Research Laboratory), Chonnam National University

Testing methods - FITI: GSI-Korea

Research on design, installation and assessment

- Korea Institute of Construction Technology

- Highway Research Center of Korea Highway Department etc.

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

ISO VERSUS ASTM VERSUS KOREAN STANDARDS

FOR GS TESTING

Most standardized geosynthetic test methods

- From JIS (Japan Industry Standard)

New standardization project by the Korea Industry Standards

- From 1998 in accordance with ASTM, GRI and ISO standards

Korea Industry Standard of geosynthetics

• General

- 2 standard test methods

- “ Glossary of geotextiles ” etc.

• Physical

- 2 standard test methods

- “ Measuring metods for thickness of geotextiles ”

• Mechanical

- 8 standard test methods

- “ Testing method for tensile strength of geotextiles ” etc.

• Hydraulic

- 4 standard test methods

- “ Measuring method for filtration aperture of geotextiles ” etc.

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

• Endurance

- 2 standard test methods

- “ Test method of weatherability of geotextiles using the Xenon-arc method ” etc.

• Miscellaneous

- 4 standard test methods

- “ Test method for friction properties of geotextiles direct shear method ” etc.

SURVEYS (MARKET ANALYSIS)

* Production of geosynthetics in 1999

Geotextiles > Geomembranes > PDB > Geogrids

* End Uses of geosynthetics in 1999

Reinforcement > Drainage/Filtration > Water barrier > Separation

DESIGN AIDS

*

Highly oriented to the geosynthetic properties of task forces for installation rather than the suitability of geosynthetic application

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

MANUFACTURING DETAILS

No significant differences between Korea and other advanced countries of North America and European nations in this regard.

(1) Geotextiles

* Woven geotextiles

High drawn split yarns (; ~3,000 denier) of high tenacity polypropylene, polyester

- Recently, the requirement of low elongation (~10%) woven geotextiles

: To improve the resistance against the fracture in installation fields

: Smart polymer resin for this purpose

* Nonwoven geotextiles

Staple fibers and filaments of polypropylene, polyester or recycled polyester with/without carbon black

- Needle punching and spunbonding methods

Specially designed manufacturing line

: to produce 8.5 m width, 3,500g/m 2 needle punched nonwovens.

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

(2) Geomembranes

* Smooth type

HDPE geomembranes with UV stabilizers and antioxidants

- Extrusion type with T-die and blown type with circular die manufacturing processes

- At least 2 mm thickness for waste landfills with the revised regulations by Ministry of Environment in 1999.

* Textured type

Spray-on(impingement) type textured geomembranes

(3) Geogrids

Fabric type geogrids : High tenacity polyester yarns and glass fibers

: PVC and acrylic resin as coating resins

(4) GCLs

Needle punched type and bentonite with adhesive/HDPE geomembrane type

Special composition of GCL layers and binder to prevent the fluid loss of bentonite

(5) PDBs

- Nonwoven geotextiles used as filters of polypropylene cores (heat bonding methods)

- Research on biodegradable filters and plastic cores to prevent environment pollution

Smart PDBs having excellent drainage performance

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

DISTRIBUTION

For domestic geosynthetics

Large companies : their own trade routes from manufacturing to marketing

Most middle and small companies : an alliance - a kind of consortium

Imported geosynthetics

- Through distributors and representatives located in Korea.

CONTRACTING

Two types of purchasing and contracting agreements in geosynthetics

By government supply and the other is individual supply

: Supply Administration the Republic of Korea

: Turnkey type organizations

By individual companies

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

CONSTRUCTION

Soft soil reinforcement - Nonwoven and woven geotextiles, PDBs, etc.

Soil retaining walls - Nonwoven geotextiles, geogrids, etc.

Waste landfills - Nonwoven geotextiles, HDPE geomembranes, GCLs, geonet composites etc.

Tunnel construction - Bentonite mixed with adhesive/HDPE geomembrane type

Subway construction - Bentonite mixed with adhesive/HDPE geomembrane type

Road & railroad construction - Nonwoven and woven geotextiles, geogrids etc.

Miscellaneous - Many types of geosynthetics associated with various end uses

SPECIFICATIONS, ACCREDITATION AND CERTIFICATION

Specifications

Agency for Technology and Standards

Ministry of Environment

Ministry of Construction & Transportation

Korean Standards Association etc.

GeoSynthetics Research Laboratory(GSRL)

Chonnam National University

Dept. of Textile Eng.

Accreditation

* FITI/GSI-Korea - GAI Accreditation Laboratory

56 items

- “ASTM D374 - Micrometer Thickness ” etc.

Certification

- No organization or institute giving geosynthetic certification

- Private certification reports by Korean experts(?)

- Test reports from foreign geosynthetic laboratories

- FITI/GSI-Korea : certification of geosynthetics in Korea

GeoSynthetics Research Laboratory(GSRL)

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