Chonnam National University Dept. of Textile Eng. GeoSynthetics Research Laboratory(GSRL)...

Chonnam National UniversityDept. of Textile Eng.

GeoSynthetics Research Laboratory(GSRL)

GEOSYNTHETICS TECHNOLOGY TRANSFER FROM A KOREAN PERSPECTIVE

Han-Yong, Jeon, Ph.D.

GSRL(GeoSynthetics Research Laboratory)Department of Textile Engineering

Faculty of Applied ChemistryChonnam National University, Kwangju, Korea



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



FACTORS AFFECTING THE POTENTIAL GROWTHOF 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 SeoulPusan/SunchunPusan • 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



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



Developmental

Geosynthetics Raw Materials Number of Manufacturers

Geotextile (woven) PP, PET 6

Geotextile (nonwoven) PP, PET 10

Geogrid (GG) polyester, glass fiber 8

Geomembrane (GM) HDPE, EVA 3

GCLs GT/bentonite/GT or GM 4

PDB GT/PP core 3

Geonet composite (GC) GT/GN/GT 2

Geopipe (GP) HDPE 1

Geofoam PS 3

Sheet drain(SD) GT/PE Core 2

Miscellaneous various 4

Table. Present State of Geosynthetics in Korea



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 cor

e

• Geonet composite – Nonwoven geotextile/geonet/nonwoven geotextile

• Geopipe – HDPE pipe (smooth and corrugated)

• Geofoam – Expanded polystyrene

• Sheet drain – Nonwoven geotextile/various drainage cores



[ Geosynthetic Products ]

• Geotextiles - Nonwovens of staple fibers : Width ~8.6m, weight ~3500g/m2 - Spunbonded nonwovens of filament fibers : ~600g/m2

- 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



• 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



Regulatory

• Regulations of geosynthetics - To be supervised by different ministries of the government

Ministry of Environment - Geosynthetics for waste landfills

Ministry of Construction & Transportation - Geosynthetics for general construction

Korea Highway Corporation - Geosynthetics 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



TRAINING, EDUCATION, SEMINARS, CONFERENCES

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

• The supervising organizations for geosynthetic related seminars and conferences in Korea

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 Foundation)



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.



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



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.



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.



• 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



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/m2 needle punched nonwovens.



(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



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



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.



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

Chonnam National University Dept. of Textile Eng. GeoSynthetics Research Laboratory(GSRL)...

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