Guide to Reinforced Fill Structure and Slope Design · Guide to Reinforced Fill Structure and Slope Design ... (Lecture 1) 2 Historical ... Reinforced Concrete Structure (Fig 7,

Guide to Reinforced Fill Guide to Reinforced Fill Structure and Slope DesignStructure and Slope Design

GeotechnicalGeotechnical Engineering OfficeEngineering OfficeCivil Engineering DepartmentCivil Engineering DepartmentThe Government of the Hong Kong The Government of the Hong Kong Special Administrative RegionSpecial Administrative Region

GEOGUIDE 6

Introductory Course (Lecture 1)Introductory Course (Lecture 1)

22

Historical DevelopmentHistorical DevelopmentReinforced fill is an established technology dating back to 4/5 BCExamples include the Great Wall of China

GEOGUIDE 6GEOGUIDE 6

33

First Reinforced Fill Wall in Hong Kong 1981First Reinforced Fill Wall in Hong Kong 1981

44

Historical Development in Hong KongHistorical Development in Hong Kong

First used in 1981Currently over 100 structures built


Tuen Mun

Guangdong Sheng

Deep Bay

Hong KongInternationalAirport

Tolo Harbour

Kowloon

Tsing Yi

Hong KongIsland

LegendLocation of ReinforcedFill Feature

Lantau Island

2422201816141210

86420

0-5

5-10

10-1

5

20-2

5

25-3

0

>30

15-2

0

Height (m)

Retaining WallFill Slope

Num

ber

Fill Slope

RetainingWall

Others RoadEmbankment

51%

14%

14%

9%

12%BridgeAbutment

55

North West North West TsingTsing Yi Yi –– 40m Reinforced Fill Wall40m Reinforced Fill Wall

66

ScopeScope

Geoguide 6 is a companion to Geoguide 1 –Guide to Retaining Wall Design (1993)Presents a recommended standard of good practice for– design– construction supervision of new permanent structures

Included are:– Walls and slopes– bridge abutments– segmental block walls

(Does not cover soil nailing, reinforced fill dams, maritime structures or embankments on soft ground)


77

Classification of Common Earth Retention Systems(Fig 13, P.145)


88

Areas of ApplicationAreas of Application

TransportationHousingSlope stabilisation and landslide mitigationOthers (industrial works, river walls)


99

The Use of Reinforcement Fill in Highway and Railway Application(Fig 2, P.134)


1010

Approach EmbankmentBridge Desk

Zone of Reinforced Fill

Levelling Strip

Bearing

Facing Panels

Highway Bridge AbutmentHighway Bridge AbutmentGEOGUIDE 6

1111

Zone ofReinforced Fill Levelling

Strip

11

Facing Panels

Retaining Wall and Embankment for RailwayRetaining Wall and Embankment for RailwayGEOGUIDE 6

1212

The Use of Reinforced Fill in Housing Development(Fig 3, P.135)


1313

Segmental Block Facing GEOGUIDE 6

1414

Other Common Usage(Fig 5, P.137)


1515

Examples of Reinforced Fill Structures


1616


Zone of Reinforced Fill

2.51

Reinforced Fill Blast Wall

1

2

1717

Rationale for the Use of Reinforced Fill

Reinforced fill structures can offer technical and economic advantages over conventional forms of constructionSavings of 20-50% of initial capital cost are possibleParticularly suited to sloping terrainLargely immune to earthquakeCompatible with the concept of sustainable development


1818

Examples of Economic and Technical Advantages of Reinforced Fill(Fig 6, P.138)


1919

Tsing Yi North Coastal Road

2020

Cyber Port Development

2121

Ecological Parameters for a 6m High Reinforced Fill Structure and an Equivalent Reinforced Concrete Structure(Fig 7, P.139)


2222

Reinforced Fill WallReinforced Fill Wall Conventional ConcreteConventional ConcreteRetaining WallRetaining Wall

GEOGUIDE 6

2323

Embodied Energy (EE) of Construction Embodied Energy (EE) of Construction MaterialsMaterials

DefinitionEnergy used to extract and transport raw materials, refine and manufacture them, package, deliver and install them on site.

Conventional RC Retaining WallConventional RC Retaining Wall

Concrete (ready mix) = 1.3 GJ/ton

Steel (virgin) = 32.0 GJ/ton

Fill = Nil

Formwork = 19.0 GJ/ton

Reinforced Fill Retaining WallReinforced Fill Retaining Wall

Concrete (precast) = 2.0 GJ/ton

Steel (galvanised) = 35.0 GJ/ton

Fill = 0.2 GJ/ton

GEOGUIDE 6

2424

Concrete Steel Fill Formwork0

20

40

60

80

100

120

140

Energy per m (GJ/m)

Construction Materials

Concrete Steel Fill Formwork0

20

40

60

80

100

120

140

Energy per m (GJ/m)

Construction Materials

for a 12 m High Wallfor a 12 m High Wallfor a 4 m High Wallfor a 4 m High Wall

RF WallRC Wall

Energy used by RF wall and RC wallEnergy used by RF wall and RC wallGEOGUIDE 6

2525

Quantity of Concrete used by RF wall and RC wallQuantity of Concrete used by RF wall and RC wall

0

20

40

60

80

100

0 2 4 6 8 10 12 14 16 18

Wall Height (m)

Ton

s pe

r m

RC Wall

RF Wall

GEOGUIDE 6

2626

Quantity of Steel used by RF wall and RC wallQuantity of Steel used by RF wall and RC wall

0.0

1.0

2.0

3.0

4.0

5.0

0 2 4 6 8 10 12 14 16 18

Wall Height (m)

Ton

s per

m

RC Wall

RF Wall

GEOGUIDE 6

2727

Quantity of Fill used by RF wall and RC wallQuantity of Fill used by RF wall and RC wall

0

50

100

150

200

250

0 2 4 6 8 10 12 14 16 18

Wall Height (m)

Ton

s per

m

RC Wall

RF Wall

GEOGUIDE 6

2828

Energy used by RF wall and RC wallEnergy used by RF wall and RC wall

0

50

100

150

200

250

300

350

400

450

0 2 4 6 8 10 12 14 16 18

Wall Height (m)

Ene

rgy

per

m (G

J/m

)

RC Wall

RF Wall

GEOGUIDE 6

2929

Reinforced Fill SystemsReinforced Fill Systems

ElementalFull heightAnchored earthWrap-aroundSegmental blocks (hybrid)


3030

Reinforced Fill Systems: ElementalReinforced Fill Systems: Elemental


(Fig 8, P.140)

3131

Forms of ReinforcementForms of Reinforcement GEOGUIDE 6

3232

Reinforced Fill Systems: Full HeightReinforced Fill Systems: Full HeightGEOGUIDE 6GEOGUIDE 6

(Fig 9, P.141)

3333

Reinforced Fill Systems: Anchored EarthReinforced Fill Systems: Anchored Earth


(Fig 12, P.144)

3434

Reinforced Fill Systems: WrapReinforced Fill Systems: Wrap--aroundaround


(Fig 10, P.142)

3535

Reinforced Fill Systems: Segmental Reinforced Fill Systems: Segmental BlocksBlocks


(Fig 11, P.143)

3636

Selection of SystemsSelection of Systems

Depends upon– Use of the structure or slope– Nature and size– Life of structure– Economy– Available fill– Aesthetics


3737

Selection of Systems: Selection of Systems: ElementalElemental

Applications– Bridge abutments– Walls– Construction on

slopes– Industrial structures– Containment dykes– Building platforms


3838

Selection of Systems: Selection of Systems: ElementalElemental

Advantages– Proven technology– Used with wide

range of reinforcement

– Good aesthetics


Limitations– Initial cost of

shuttering for new units high

– Need to test new units

3939

Selection of Systems: Full HeightSelection of Systems: Full HeightApplications– Bridge abutments– Retaining walls– River training works– Industrial structures


4040

Advantages– Rapid construction– Very robust– Eliminates failure

through the facing– Good finishes

(pretensionedconcrete)


Limitations– Limited to 10m

height– Needs propping– Good compaction

required

Selection of Systems: Full HeightSelection of Systems: Full Height

4141

Selection of Systems: WrapSelection of Systems: Wrap--aroundaround

Applications– Steep slopes– Slope repairs– Tall embankments– Blast walls– Rock fall protection


4242

Advantages– Use of indigenous

fill– Economic– Green structures– Composite

reinforcement/ drainage used with fine fill


Limitations– Facing susceptible

to fire/vandalism– Must protect

against UV light

Selection of Systems: WrapSelection of Systems: Wrap--aroundaround

4343

Selection of Systems:Selection of Systems:Anchored EarthAnchored Earth

Applications– Bridge abutments– Walls– Slope repairs– Noise barriers– Blast barriers


4444

Advantages– Improved pullout– Use of waste

materials (tyres) produces economic structures


Limitations– Not used with

wrap-around systems

Selection of Systems:Selection of Systems:Anchored EarthAnchored Earth

4545

Selection of Systems:Selection of Systems:Segmental BlockSegmental Block

Applications– Housing– Low/medium walls– Bridge abutments– Superimposed

structures


4646

Advantages– Proven technology– Rapid construction– Minimal

construction plant– (Used with

indigenous fill)– Wide range of

facings


Limitations– Usually no provision

for differential settlement between facing/fill

– Little adaptability to differential settlement

Selection of Systems:Selection of Systems:Segmental BlockSegmental Block

4747

Proprietary Systems and Proprietary Systems and ProductsProducts

Proprietary products/systems often restricted to specific applicationsSome proprietary products only suitable for use with proprietary systemsSome systems are covered by Patents


4848

Certification of Reinforcing Certification of Reinforcing ProductsProducts

Ensure safe long-term design strengthEnsure adequate quality assurance of productsEliminate repetitive checking

Objectives of Certification

GEOGUIDE 6

4949

Certification Procedure


Manufacturer submits product details to GEOReinforced Fill Advisory Panel (RFAP) assesses the submissionRFAP submits draft certificate to Endorsement Committee for review and agreementDirector of Civil Engineering (DCE) signs the certificate

GEOGUIDE 6

5050

Types of Reinforcing Products


Metallic reinforcing products do not require certificationReinforcing products, the strength and stress-strain characteristics are temperature and time dependent require certification

GEOGUIDE 6

5151

GEOGUIDE 6(Fig 23, P.155)

5252

Viscoelastic Behaviour Viscoelastic Behaviour of Polymerof Polymer

Strain (%)

Loa

d (k

N/m

) IncreasingStrain Rate

5353


IncreasingTemperature

Strain (%)

Loa

d (k

N/m

)

5454


Strain Rate (%/min)

(Pea

k L

oad)

/(Ind

ex V

alue

)x10

0%

IncreasingTemperature

5555

Assessment Details


Creep and stress rupture

GEOGUIDE 6

5656

Sustained Load Creep TestSustained Load Creep Test GEOGUIDE 6

5757

Interpretation of Sustained Load Creep TestInterpretation of Sustained Load Creep Test

Stra

in (%

)

Time (hr)

Creep Curves

5858

Interpretation of Sustained Load Creep TestInterpretation of Sustained Load Creep Test

Strain (%)

Loa

d (k

N/m

)Isochronous Curves

5959

Assessment DetailsCreep and stress rupture


Oxidation and hydrolysis

CED Homepage (www.info.gov.hk/ced) provides details of the certification system and submission requirements

Installation damage

GEOGUIDE 6

6060

END OF LECTURE 1END OF LECTURE 1

Documents

Guide to Reinforced Fill Structure and Slope Design · Guide to Reinforced Fill Structure and Slope Design ... (Lecture 1) 2 Historical ... Reinforced Concrete Structure (Fig 7,