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University of Incheon
Korean Practice of Earth Reinforcement in Combination with Other Methods
E.C. Shin
University of Incheon, Korea
12th Asian Regional Conference On Soil Mechanics And Geotechnical Engineering
University of Incheon
1. Introduction
2. Old History of Reinforced Earth Application
3. Reinforced Earth Wall
4. Modular Block Faced Geosynthetics Reinforced Walls
5. Reinforced Slope with Vegetation
6. Conclusion
Contents
University of Incheon
Traditional reinforced earth wall for HousingWooden frame + Mud-ball (Mud + Chopped reeds,or Rice straw)
Modern reinforced earth technology in Korea
First introduction ; No.3 Highway in 1980Year 2000 ; 10,191 thousand m2
Reinforcing materials ; Stiff & Flexible geogrids, Geosynthetic strip type,
Galvanized steel strip, Soil nailing, Wire mesh type
Introduction
University of Incheon
Reinforced earth embankment for the protection of castle
Utilized the natural material; soil, rice straw
wooden pole & stick,
Widely used in 5 century
Prevailed in the Northeast Asia
Old History of Reinforced Earth Application
Reinforced earth embankmentfor castle wall (Lee,1998)
University of Incheon
The wall of an old house
Utilized the natural material; mud brick & mud ball (mud + Chopped rice straw)
Old History of Reinforced Earth Application
Reinforced mud withchopped rice straw
The length of chopped rice straw inside of the wall ; 3 ~ 9cmoutside of the wall ; 1 ~ 2cm
University of Incheon
Old temple (Bongjongsa Temple)
Built in AD 672 during the Unified Sila DynastyDesignated No.55 on January, 1963The wall built by using the reinforced earth technology
Old History of Reinforced Earth Application
Bongjongsa Temple
Located in southeast of part of Korean, Kyoungbuk Province
University of Incheon
Old temple (Bongjongsa Temple)
Old History of Reinforced Earth Application
University of Incheon
Old temple (Bongjongsa Temple)
Old History of Reinforced Earth Application
University of Incheon
Old temple (Bongjongsa Temple)Construction of reinforced earth wall
Old History of Reinforced Earth Application
Completed wooden framework
Wooden lattice framework
University of Incheon
Old temple (Bongjongsa Temple)The roof of Bongjongsa Temple
Old History of Reinforced Earth Application
Completed wooden framework
Wooden lattice framework
University of Incheon
The reinforced earth wall technology in Korea Retaining natural soil slopeEmbankmentApproach embankment of bridge flyovers
The types of wall facing of reinforced earth wallGeosynthetic soft facingHard concrete facing (Reinforced Earth Wall (REW), Modular block)
Precast concreteOverlapping jointCompressive fillerVarious size and shapes Fit design requirement
Reinforced Earth Wall
University of Incheon
Reinforced Earth Wall
Yongin, Kyounggi ProvinceCompletion ; November, 1996To gain the extra land
Belt type continuous stripCarbon rod ; L = 17.5cm,
D = 25mm or 32mm
Reinforced earth wall for apartment complex
University of Incheon
Reinforced Earth Wall
Southwest part of Seoul Metropolitan
Completion ; July 1988
Height ; 16m
Two stages of reinforced wall
A small berm in-between the 1st
staged wall and 2nd staged wall
Sadang Daelim apartment complex
University of Incheon
Reinforced Earth Wall
Locate ; Sungnam, Kyounggi Prov.
Completion ; November, 1992
Cut to secure the earth slopeagainst sliding failure
Approach embankment for overpass bridge
Kyoungchung Highway
University of Incheon
The Modular Block extensively used in Korea Side wing of an approach embankment of bridge flyoversResidential & office buildings Apartment complex and industrial factory complex in the hilly area
Various types of facial modular block maid in Korea
Modular Block Faced Geosynthetic Rein. Walls
(a) (b) (c) (d)
University of Incheon
Geosynthetic Reinforced Walls
0.6
12.773
51.332
22.622
80
65
55
95.027
0
20
40
60
80
100
80 82 86 88 90 92 94 95 96 97 98 99 2000
Years
Constructed quantity
(m2, x 1,000)
Concrete panel type faced reinforced wall
University of Incheon
Geosynthetic Reinforced Walls
200
500700
1100
1500
2600
0
500
1000
1500
2000
2500
3000
80 82 86 88 90 92 94 95 96 97 98 99 2000
Years
Constructed quantity
(m2, x 1,000)
Modular block type faced reinforced wall
University of Incheon
Modular Block Faced Geosynthetic Rein. Walls
Modular block faced geogrid reinforced wall in Korea
University of Incheon
Modular Block Faced Geosynthetic Rein. Walls
Approach embankment of bridge flyover
University of Incheon
Modular Block Faced Geosynthetic Rein. Walls
Slope stability problem in the certain environment particulaly
Failure of modular block faced geosynthetic reinforced wall
Modular block facedgeosynthetic reinforced wallfor apartment complex
University of Incheon
Geosynthetic reinforced slope with vegetation Fiber reinforced sand spray with special equipment Percentage of multifiber ; 0.15~0.25% by weight of sand
Geocell System ; Highway embankment & railway trackFilling material ; gravel, sand, any types of natural soil
HDPE cell system ; lateral confinement & faciltate drainage
Mesh type facing slit wall with chain anchor system
Reinforced Slope with Vegetation
University of Incheon
Fiber reinforced slope with sand spray
Right after construction
Vegetation growth
University of Incheon
Slope reinforcement by geocell
Right after construction
Vegetation growth
University of Incheon
Reinforcement material : galvanized metal chainPullout test and field test
Slit reinforced slope
University of Incheon
Types of chain reinforcement
Chain only
Chain + horizontal bar+ L type angle
Chain + L type angle
University of Incheon
Reinforced Slope with Vegetation
Chain only
Chain + horizontal bar
Chain + L type angle
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.40
500
1000
1500
2000
2500
Ulti
mat
e P
ullo
ut F
orce
(kgf
)
Normal stress(kg/cm2)
Chain+Ang le 2.0m:Theory Chain+Ang le 2.5m:Theory Chain+Ang le 3.0m:Theory Chain+Ang le 2.0m:Field Test Chain+Ang le 2.5m:Field Test Chain+Ang le 3.0m:Field Test
Comparison between the laboratory pullout test and field test
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
500
1000
1500
2000
2500
Ulti
mat
e P
ullo
ut F
orce
(kgf
)
Normal stress(kg/cm2)
Chain+Bar 2. 0m :Theory Chain+Bar 2. 5m :Theory Chain+Bar 3. 0m :Theory Chain+Bar 2. 0m :Field Test Chain+Bar 2. 5m :Field Test Chain+Bar 3. 0m :Field Test
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.40
600
1200
1800
2400
Ulti
mat
e Pu
llout
For
ce(k
gf)
Normal stress(kg/cm2)
Chain 2. 0m : Theory Chain 2. 5m :Theory Chain 3. 0m :Theory Chain 2. 0m :Field Test Chain 2. 5m :Field Test Chain 3. 0m :Field Test
University of Incheon
Slit reinforced method
Vegetation growth
Right after construction
Vegetation growth
University of Incheon
Conclusion
The reinforcing materials in the early days ; chopped rice straw, reed, and wooden stick
Modern reinforced earth technology ; year 1980.
In the 1980s: reinforced earth wall, hard concrete flat panel facing
Since the mid 1990s ; Modular block faced segmental reinforced wallsRecently, the geosynthetic reinfored walls with modular block facing are more common practice to extend the land around apartment complex in the hilly area
Geosynthetics combined with other methods are necessary to provide the services with soil reinforcement and slope protection
