lumpy fill inland reclamation

8/12/2019 Lumpy Fill Inland Reclamation

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Dr. R. G. RobinsonDepartment of Civil EngineeringIIT Madras, India

Lumpy fill in land reclamation


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Prof. Tan Thiam Soon


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Dr. Ganeswara Rao Dasari


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Contents of Presentation

Overview

Coastal Reclamation

Lumpy fill Laboratory studies on lumpy fill

Field Tests

Conclusions


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Overview

Coastal reclamation


Field tests

Conclusions



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Original land area : 580 km2

Population: 4 millionExpected to increase to 5.5 millionin 40-50 years


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Overview

Coastal reclamation


Field tests

Conclusions



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Stages of Reclamation

Stage I- Planning

Identify the area to be reclaimed. (HDB, JTC and

PSA are the major agencies).

Stage II-Environmental Impact Assessment

Tidal flow patterns, water level, sedimentationand water quality.

Impact on sea life.

Erosion of main land and silting of ports.

Convince and get approval from Parliament.


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Stage III- Construction of sand bunds along the

perimeter to contain the fill

Stage IV-Placing of fill within the sand bund

Sand

Clay Hydraulic fill

Lumpy fill

Stage V-Soil stabilization Dynamic compaction if it is sand fill

Surcharge if it is clay

.. Stages of Reclamation


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560

600

640

680

720

760

1940 1960 1980 2000 2020

Year

Landarea

(km

2)

2000

3000

4000

5000

6000

1960 1980 2000 2020

Year

Pop

ulationdensity

(person/km

2)

Land Area Population density


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Land Reclamation in Singapore-Growing city state

Southern IslandsSentosa

Pasir Panjang Port

Tuas

Jurong Island

Punggol

Marina Bay

Tekong/Ubin

Changi Airport

Reclaimed area=31%

Kranji

Strait Times (2000)


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Land Reclamation in Singapore-Some major projects

Year Site Area (ha) Vol. of

sand, Mm3

1974-1979 Changi airport 750 40

1983-1986 Changi north 181 12

1985-1989 Tuas 637 69

1981-1985 Pulau Tekong Besar 510 28

1992-2005 Changi East 2086 272


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Reclamationdepth

increasing

In-land

materialsdepleted

High cost ofimported

sand

IncreasingUndergroundConstructions

Maintenanceof Navigation

Channels

Lack ofdisposalground


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HYDRAULIC FILL- Clay slurry

Contains mainly slurry with occasionaloccurrence of small lumps suspended inslurry

Apply surcharge to consolidate

Double handling

Cannot handle unwanted soil directly


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40 ha (1988) Trial project

Clay slurry 200% water content

after 1 week

Sand cap can be formed for dosage

< 15 cm

Careful construction control crucial

to prevent sand loss

Sand placement rather time-consuming

Cannot handle waste soils directly

Changi south bay

Layered sand-clay scheme (Karunaratne et al. 1990)

Seabed

Clay slurry

Clay slurry

Clay slurry


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Overview

Coastal reclamation


Field tests

Conclusions



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CLAY LUMPS

Produced by underground construction & seabeddredging

Volume of lumps can easily exceed 1 m3

Waste soil (unwanted soil) can be handled directly

Dredging of seabed Lumps placed in a barge

1.0mClamb-shell grab


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Lumpy Fill

Dredging of seabed

Clamshell grab

- Place the material in the form of lumps,

directly at the reclamation site

Cl l l d i b


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Clay lumps placed in a barge

D i f l l b b tt b


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Dumping of clay lumps by bottom-open barge

Barge size:

Width: ~10 mLength: ~20 mDepth : ~5 mVolume: 900-1000 m3

T i l L d R l ti S h


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Seabed

Sand surcharge

Clay lumps

Inter-lump voids

Filled water

Mean sea level

Typical Land Reclamation Scheme

S


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Some aspects.

Consolidation behaviour

Closing of inter-lump voids

Shear strength of the fill after stabilization

Creep/Secondary compression

Influence of clay slurry in the inter-lump voids

Effect of degree of swelling


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Overview

Coastal reclamation


Field tests

Conclusions


T i l b d fil


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Typical seabed profile

0 4 8 12Corrected cone resistance, qt(MPa)

35

30

25

20

15

10

5

0

Depthbelowseabed(m)

0 0.4 0.8 1.2 1.6 2Pore pressure, u

2(MPa)

Pore pressure

Cone resistance

Surface soft marine clay

Upper marine clay

Intermediate layer

Lower marine clay

Weathered rock

~8200 years

~24000 years

~28000 years

Forms slurry

Forms lumps

Forms lumps

May or may notform lumps

After dredging

S il d f th t d


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Soil used for the study

Depth : 13mLL=77%PL=36%

PI=41%Sand=5%Silt size=55%Clay=40%

NMC=60%

1.5 m


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One-dimensional consolidation tests


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0

0.2

0.4

0.60.8

1

1.2

1.41.6

1.8

0.1 1 10 100

Time, min

Settlement,mm

Cv=1.25 x 10-3cm2/s

H = 19 mmDouble drainage

Typical time-settlement curve

e-log s curves from conventional oedometer tests on


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e log sv curves from conventional oedometer tests onhomogeneous clay

1.0

1.5

2.0

2.5

1 10 100 1000

Consolidation pressure, kPa

Voidratio,e

Undisturbed

ICL

sc=200 kPaOCR= 2.5


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Tests on lumpy fill

Preparation of clay lumps


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Preparation of clay lumps

Cut using wire cutter

25 mm cubical lumps

Experimental set-up


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LVDTBurette

Loading frame

Perforated loading cap

Geotextile filter

Geotextile filter

Clay lumps

Sand drain

Experimental set up

Experimental Programme


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1. Effect of packing (using 25 mm lumps)

1. Placed directly in water-Test 12. Packed in the container and then added

water

(Test 2 and Test 3)

2. Effect of size12.5, 25, 50 mm cubical lumps

3. Effect of degree of swelling

Degree of swelling =0% 50% and

100%

Experimental Programme

State of the fill under different consolidation pressures in Test 1


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0 kPa 10 kPa

50 kPa27 kPa

p

100 mm

Effect of initial packing on e-logsv curves


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1

1.5

2

2.5

3

3.5

1 10 100 1000


Voidratio,e

Test 1 (eiv=1.05, e=4.31

Test 2 (eiv=0.93, e=3.99)

Test 3 (eiv=0.57, e=3.07

Undisturbed

ICL

Effect of initial packing on e logs vcurves

25 mm cubical lumps

Effect of size on e-logsv curves


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1

1.5

2

2.5

3

3.5

1 10 100 1000


Voidr

atio,e

12.5 mm25mm

50 mm

Effect of size on e logs vcurves

eiv= 0.600.03

Typical time-settlement curves


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0

0.2

0.4

0.6

0.8

1

1 10 100 1000 10000 100000 1000000

Time, s

Normalizedsettlement

16-27 kPa

27-50 kPa

50-100 kPa

100-200 kPa

200-400 kPa

Test 1

yp


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Typical e-log sv curves of lumpy fill


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yp g v py

1.0

1.5

2.0

2.5

3.0

3.5

1 10 100 1000


Void

ratio,

e

Lumpy fill

Undisturbed

ICL

e0= 1.59

sc=200 kPa

Lump size : 25 mmNo. of lumps: 90Fill height: 170 mm

Permeability of lumpy fill system


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y py y

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1 10 100 1000


Coefficientofpermeability,m/s

Lumpy fill

Undisturbed

ICL

Lump size : 25 mmNo. of lumps: 90Fill height: 170 mm

Cone penetration test on lumpy fill


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p py

Lump size : 50 mmPenetration rate: 5mm/s

The Cone

3 mm

30mm

10 mm

k

vocu

N

qs

s

su Undrained shear strengthsvo Overburden pressureNk Cone factor

Nk = 9.5 against vane shear

CPT were conducted undersv=50, 100, 200 and 360 kPa

Load CellThanks to Hokuto Ricken Co., Japan

Shear strength profile under 50 kPa


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g p

0

20

40

60

80

100

120

140

0 10 20 30 40 50

su, kPa

Depth,mm

su

=0.23v

'

su=0.23v' (OCR)0.75



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g p

0

20

40

60

80

100

120

140

0 10 20 30 40 50

su, kPa

Depth,mm

su=0.23 v'

su=0.23v' (OCR)0.75



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0

20

40

60

80

100

120

140

0 10 20 30 40 50

su, kPa

Depth,mm

su=0.23 v'

g p



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0

20

40

60

80

100

120

140

0 20 40 60 80 100

su, kPa

Depth,mm

su=0.23 v'

g p

Secondary compression of lumpy fill


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0

1

2

3

4

10 100 1000

Average consolidation pressure, kPa

C

(%)

Undisturbed

ICL

12.5 mm

25 mm

50 mm

0.01

0.02

0.03

0.04

0.05

0.06

0.07

10 100 1000

Average consolidation pressure, kPa

(C/C

c)

(C/Cc) = 0.03

(C/Cc) = 0.05

Coeff. of Secondary Compression Mesris (C/Cc) concept


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Influence of clay slurry

Inter-lump voids filled with water Inter lump voids filled with slurry


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Lump

Water

Lump

Clay slurry

Lump

Inter-lump voids filled with water Inter-lump voids filled with slurry

Experimental set-up


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LVDTBurette

Loading frame

Perforated loading cap

Geotextile filter

Geotextile filter

Clay lumps

Sand drain

Typical time-compression curves


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1 100 10000 1000000Time,s

16

12

8

4

0

Settlem

ent,mm

ILV with water

ILV with slurry

(w=150%)

ILV with slurry(w=300%)

(a) 6-12 kPa

.Typical time-compression curves.


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1 100 10000 1000000Time, s

12

8

4

0

Settlement,mm

ILV with water



(b) 50-100 kPa

.Typical time-compression curves


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1 100 10000 1000000Time, s

12

8

4

0

Settle

ment,mm

ILV with water


ILV with slurry

(w=150%)

(c) 200-400 kPa

Applicability of Terzaghis theory


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0

20

40

60

80

100

0.0001 0.001 0.01 0.1 1 10

Time factor (Tv)

Degreeofconsolidation(%)

Terzaghi's Theory

6-12 kPa (150%)

12-25 kPa (150%)

6-12 kPa (300%)

12-25 kPa (300%)

e-log svcurves


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1 10 100 1000Consolidation pressure, kPa

0.5

1

1.5

2

2.5

3

Voidratio,e

Undisturbed

ICL

ILV with water

ILV with slurry (w=150%)

ILV with water (w=300%)

Variation of permeability with consolidation pressure


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1 10 100 1000Consolidation pressure, kPa

C

oefficientofperm

eability,m/s

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4 UndisturbedICL

ILV filled with water

ILV filled with slurry (w=150%)

Pore pressure inside and in between the lumps


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0

5

10

15

20

25

30

1 10 100 1000 10000 100000

Time, s

Porepressure,kPa

Dsv=25 kPa

0

5

10

15

20

25

30

1 10 100 1000 10000 100000 1000000

Time, s

Porepressure,

kPa

25-50 kPa

Dsv=25 kPa

Inter-lump voids with water Inter-lump voids filled with slurry

Inside the lump

In between the lumps

Inside the lump


25-50 kPa

Pore pressure inside and in between the lumps


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Inter-lump voids with water Inter-lump voids filled with slurry

0

20

40

60

80

100

120

1 10 100 1000 10000 100000 1000000

Time, s

Porepressure,

kPa

100-200 kPa

0

20

40

60

80

100

120

1 10 100 1000 10000 100000 1000000

Time, s

Porepressure,

kPa

100-200 kPa

Inside the lump


Dsv=100 kPaDsv=100 kPa

Influence of swelling of lumps


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Swelling testTo find the time required for different degrees of

swelling

Degree of Swelling, Us

w= moisture content of the specimens afterimmersing in water at any instant of time

wi = initial moisture content of the specimen

wf = moisture content of the fully swollen specimen

100isf i

w wUw w

Time

Us

For a cubical lump of 25 mm, t50=20 min

Lumps in the field are very large and may not reach fully swollen stateif sufficient time is not allowed before the application of surcharge

State of the lumpy fill under sv = 50 kPa (25 mm lumps)


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Us= 0%

Us=50%

Us=100%


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Swelling of clay lumps

THREE DIMENSIONAL SWELLING OF CLAY LUMPS


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Method I

Obtain the water content of the lump with timeduring swelling.Suitable for small size lumps only

Method II

Obtain the volume change with time during swellingNot simple for three-dimensional swelling

Method III

Obtain the pore-pressure dissipation with timeSimple and easy to make the measurements

Three dimensional swelling of clay lumps


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Soils used

Kaolinite:LL=82%, PL=40%

Cylindrical samples of105, 205 and 400 mm

Marine clay:LL=56%, PL=33%

Cylindrical samples of105 and 205 mm

PPTTensiometer

28 mm

12 mm

Instrument used

6 mm diameter

Performance of PPT in comparison with Tensiometer during desiccation


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0

20

40

60

80

100

0 5000 10000 15000 20000

Time, min

Suct

ion,

kPa

PPTTensiometer

240 mm

240mm T PPT

EXPERIMENTAL PROCEDURE


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Lump Outer container

Filter

Split mould

Load

Water

Schematic of the split mould for conducting swelling test


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400

650

550

750

160

160

160

160 Clay

Slurry

Split

mould

Outer container

Pore pressure

transducers

50

Bottom sand

drain

(All dimensions are in mm)

400PPT-1 2

3 4 5 6

7 8

Geotextile

View of the split mould for conducting swelling test


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Pneumatic piston

Split mould

Outer container

View of the kaolinite lump of 400 mm diameterafter removing the split mould


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400 mm

after removing the split mould

Dissipation of suction on submerging the kaolinite lumpof 400 mm diameter in water


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0

0.2

0.4

0.6

0.8

1

1.2

1 10 100 1000 10000 100000

Time, s

Normalizedsuction(u/u0)

400PPT-3

400PPT-5400PPT-6

Clay lump

50 mm

400PPT-3 4 5 6

7 8

97.5

195

97.5

Normalized suction at the centre of marine clay lumps


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0

0.2

0.4

0.6

0.8

1

1.2

1.4

1 10 100 1000 10000 100000 1000000

Time, s

Normalizeds

uction(u/uo)

105 mm

205 mm

Initial state End state


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Kaolinite

Marine clay

Variation of water content within the marine clay lump of205 mm diameter after full swelling


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205 mm diameter after full swelling

0

4

8

12

16

20

42 44 46 48 50 52 54 56

Water content (%)

Depth,cm

wowl

Water content variation within the lump-Undisturbed


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60

65

70

75

80

-30 -20 -10 0 10 20 30

Distance from centre of lump, mm

Watercontent(%)

wL

wo

Cube : 50 mm


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Finite Element Analysis

Fi i El h

Finite Element Analysis


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Finite Element mesh


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Effect of soil model (Kaolinite lump 105 mm diameter)

A k l d t D G R D i


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1 10 100 1000 10000

Time,s

0

0.2

0.4

0.6

0.8

1

1.2

Norma

lizedpore

pressure

(1) Linear Elastic

LE

(2) Non-linear Elastic (NLE1)

k

')1('

peK

NLE1

(3) Non-linear Elastic (NLE2)

k= 0.005 +0.10 log (OCR)

NLE2

(4) NLE2

-Permeability increased

(4)

Acknowledgement: Dr. Ganeswara Rao Dasari

Predicted and measured suctions at the centre of marine clay lumps


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0

0.2

0.4

0.6

0.8

1

1.2

1.4

1 10 100 1000 10000 100000 1000000

Time, s

Normalizeds

uction(u/uo)

Measured (105 mm diameter)

Measured (205 mm diameter)

NLE2 (105 mm diameter)

NLE2 (205 mm diameter)

Big Tank Experiment


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3500

1000

1500

I-section

457x152x67

I-section

152x152x37Base for fixing

hydraulic jack

1" thick plate

I-section

305x165x46

Stiffner305

2280

1.4m

1.5m

SAMPLE PREPARATION


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DREDGED & PLACED IN A FLAT BARGEPACKED IN BAGS & TRANSPORTED TO THE LAB

CUT TO CUBICAL LUMPS OF 150 MM

STORED IN CONTAINERS AFTER COVERINGWITH CLING-FILM


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Size of lumps : 15 cm

No. of lumps : 223No. of layers : 6Total weight : 1.37tHeight of fill : 93 cm


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Overview

Coastal reclamation

Lumpy fill

Laboratory studies on lumpy fill

Field tests

Conclusions



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NUCLEAR DENSITY CONE ND-CPT


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Density is related to scattering

of gamma ray

Cesium source Cs137with halflife of 37.6 years

Housed in standard CPT: Diameter = 35.6 mm

Cone angle = 60

Cone area = 10 cm2

Penetration = 1.5 cm/sec

30 cmDiameter

Calibration Curve


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Density Count Ratio (Rp) = [RI Count BG Count ] / Standard Count

LUMPY FILL TEST SITE AT PULAU PUNGGOL TIMOR


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Reclaimed 14 years ago

8 m dredged fill &

10 m sand fill


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Final density of lumpy fill

3


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14

15

16

17

18

14 16 18 20 22

Wet Density (kN/m3)

Depth(m)

RI 21

BH8- Direct

measurement

BH8-from

water content

Final shear strength of lumpy fill


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14

15

16

17

18

0 40 80 120 160 200

Undrained Shear Strength, (kPa)

Depth(m)

14

15

16

17

18

30 50 70 90

Undrained shear strength (kPa)

Depth(m)

BH 1

BH 2

BH 3

BH 4

BH 6

0.23sv'

Cone Penetration Test UU Test

0.23 sv

Preconsolidation Pressure (kPa)

Oedometer test results


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14

15

16

17

18

100 200 300 400

Preconsolidation Pressure (kPa)

Depth(m)

BH 1BH 2BH 3

BH 4BH 5

BH 6

sv'

OCR=1

OCR=2

C t t f P t ti


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Overview

Coastal reclamation

Lumpy fill

Laboratory studies on lumpy fill

Field tests

Conclusions


SOME ISSUES


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Time-settlement of lumpy fill

Double porous

Heterogeneous initial condition

Pore pressure generation and dissipation

Swelling of clay lumps

Time-swell

End state

Acknowledgements


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NSTB and HDB for funding

Toa Corporation : Contractors for reclamationKiso-Jiban : Contractors for in-situ Testing

Researchers:

Mr. M. Karthikeyan Research EngineerMr. Yang Li-Ang Research EngineerMr. A Vijayakumar Research ScholarMs. Goh Wen Jean FYP

Ms. Lim Chea Rong FYPMs. Lim Hsiao Chern FYPMr. Lim Chee Kiong FYP

d f l d h


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Had Useful discussions with:

Dr. D. W. Hight Geotechnical Consulting Group, London, UK

Prof. J. Locat Laval University, Canada

Dr. H. Tanaka Port and Airport Research Institute, Japan

Prof. M. Mimura Kyoto University, Japan

Mr. M. Nobuyama Soil and Rock Engg. Co. Ltd., Japan

Prof. J .Takemura Tokyo Institute of Technology, Japan


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Thank you

lumpy fill inland reclamation

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