Large man-made airport islands in Japan

Transcription

2008/10/9
Tokyo International Airport (Haneda Airport):
Large man-made airport islands in Japan:
History of reclamation technology and
recent interpretation of long-term consolidation
The offshore expansion project, in which the airport was constructed on an
ultra-soft clay deposit, was carried out from 1984 to 2004. The further expansion
project with the 4th-runway is under construction. The new runway will be a
hybrid island of landfill and bridge. In the reclamation part, a large amount of
cement treated clay and air-foam treated lightweight clay will be used.
7th October 2008
Geotechnical seminar
Jointly organized between
Geotechnical Society of Singapore (GeoSS)
& Centre for Soft Ground Engineering, NUS
Tokyo
Yokohama
Yoichi WATABE
Port and Airport Research Institute, Japan
New Kitakyushu Airport:
Central Japan International Airport:
The new airport, constructed on an ultra-soft clay deposit, was inaugurated in
March 2006. The construction technology was similar to the offshore expansion
project of the Tokyo International Airport.
The airport was inaugurated in 2005. Some part of the island was reclaimed by
cement treated clay.
Nagoya
Kokura
Kansai International Airport:
The first phase was inaugurated in September 1994. The second phase with a
parallel runway is operational since August 2007. The reclamation technology is
quite normal, but the estimated settlement is over 14 and 18 m in the first and
second phases, respectively.
This lecture will discuss these reclamation technologies which
overcame various severe conditions such as
-Thick soft clay deposit,
-Large water depth,
-Lack of geo-materials,
period, etc.
-Short construction p
Kobe
Osaka
In addition, PARI has studied long-term consolidation of
Osaka Bay clay retrieved from the construction site of
the Kansai International Airport.
The lecture will then discuss recent knowledge on the strain rate
effect for the long-term consolidation behavior obtained in the
laboratory tests, in association with the isotache concept.
1
2008/10/9
Reclamation history of the Tokyo International Airport
1931
1931
1946 A-runway with 2100 m
B-runway with 1650 m
1955 Terminal building
B-runway with 1675 m
1959
1945
A-runway
1938
1964 C-runway with 3150 m
1971 B-runway with 2500 m
C-runway
A-runway
C-runway
A-runway
1988 Completion of 1st phase
New A-runway with 3000 m
Disposal Facilities
for construction
waste soil
& dredged clay
Disposal Facilities
for construction
waste soil
& dredged clay
C-runway
C-runway
1986
New AA-runway
2
2008/10/9
1993 Completion of 2nd phase
New terminal building ”Big bird”
1990
Disposal Facilities
for construction
waste soil
& dredged clay
C-runway
New AA-runway
Staged construction plan for the offshore expansion
project of the Tokyo International Airport
Disposal Facilities for
construction waste soil
& dredged clay
Disposal Facilities for
construction waste soil
& dredged clay
1997 New C-runway with 3000 m
New A-Runway 3,000m
C-Runway 3,150m
B-Runway 2,500m
From 1984 to 1988
-A-Runway open
From 1971 to 1984
Before project
Tokyo Monorail
Tokyo Monorail
Offshore extension of
Disposal Facilities for dredged clay
1st phase
New C-Runway 3,000m
Terminal 2
Terminal 1
Access road
& Expressway
Access road
& Expressway
Tokyo Monorail
Access
road
New B-Runway 2,500m
From 1988 to 1993
-Terminal building 1
2nd phase
Train
Tokyo Monorail
From 1993 to 2006
-New C-Runway open in 1997
-New B-Runway open in 2000
-Terminal 2 open in 2004
-Terminal 2 south-pier open in 2007
3rd phase
Further expansion project (under construction)
Ｄ-runway
Ｃ-runway
2,500m
3,000m
Ａ-runway
3,000m
-Tokyo International Airport
-New Kitakyushu Airport
Common technology
ÆReclamation with ultra-soft dredged clay
Hydraulic transportation of dredged soil
Kitakyushu Airport
Ｂ-runway
2,500m
International
terminal
The Tama-River
ultra-soft
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2008/10/9
Tokyo International Airport
Cracking by desiccation
but still ultra
ultra--soft
Ultra--soft clay deposit
Ultra
Raising water level for working vessel
Rope--net laying
Rope
Preparation for ground improvement
Lime-mixing for trafficability.
Kitakyushu Airport
Kitakyushu Airport
Hydraulic transportation of sand
Installation of plastic board drains
Sand drain method:
A very permeable sand is used for drain
columns.
-The most popular and proven technology
in coastal engineering in Japan.
-To accelerate the consolidation settlement
in a wide area
Sand filling
-Large installation capability.
Granulated blast furnace slag
-High drainage capacity.
Total installation length in Haneda:
3,000 km (approx. Tokyo–Hong Kong)
1
Packed sand drain method:
2
A permeable sand is packed in a synthetic
fiber bag and installed as drain columns.
-Assured continuity of the drainage even if a
significant deformation happens in the clay
layer.
Installation of sand drains
Earth filling
4
3
Consolidation under a preload
-Small volume of sand by adopting a small
drain diameter.
-Twice the number of drains, but half the
working period, by adopting an installation
machine which can operate 4 columns
simultaneously.
Removing the earth fill
(Preloading method)
19,000 km (approx. Tokyo–Rio de Janeiro)
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2008/10/9
The Tokyo International Airport
Plastic board drain method:
Permeable plastic board drains are installed
into the ground.
-Small disturbance of the ground during the
installation.
-Uniform drain performance in the depth
di ti
direction.
-Some residual settlements during airport operation
have been allowed, because the construction period
was limited to meet passengers’ demand.
-Maintenance and repair will be needed, because some
differential settlements are inevitable.
-Ground
G
d conditions
di i
are not uniform,
if
b
because
the
h
construction took a long period (about 15 years).
14,500 km (approx. Tokyo–Cape Town)
-Temporary seawalls and partitions, which had been
used during a period of disposal facilities for
construction waste soil/dredged soil, cause differential
settlement.
The Tokyo International Airport
Improve accuracy for settlement prediction is necessary
for maintenance and repair works:
PBD
-Hyperbolic curve fitting method was used for the
settlement–time prediction.
Æ The parameters obtained were very different from
the laboratory test results .
Æ The calculation was retried in consideration of the
stress history and laboratory test data.
The parameters were set within a range of data
variation.
3.8
Holocene clay
Time
approox.
8m
Æ Theoretical calculation was attempted to obtain a
good
d fitting
fitti with
ith consolidation
lid ti parameters
t
Cc, cv & pc.
Preload removal
Earth fill
Sand mat
Construction waste soil
Dredged clay Lime mixing
SD
1y
year
Settlement
Calculation in consideration of stress history and soil data
Δp
The New Kitakyushu Airport
3.4
Original designp関係
当初設計時のe－log
Void
ratioe e
間隙比
3.0
Obtained by fittingp関係
フィッティングのe－log
2.6
2.2
1.8
1.4
1.0
Many similar conditions to the Tokyo International
Airport.
-Constructed on a soft clay deposit
-Reclaimed with dredged clay in ultra-soft state
The residual settlement was minimized
-To minimize the maintenance cost, even though the
initial cost was high.
To minimize the residual settlement/differential settlement,
drain spacing was adjusted.
0.6
5
10
20
50
100
200
500 1000 2000
Consolidation
圧密圧力pressure
p (kPa) p (kPa)
5
2008/10/9
10000
cv (cm2/d)
Reclamation with hydraulic transportation for a dredged soil
results in grain-size segregation.
Near the outlet: large particles (sand)
Far from the outlet: fine particles (silt & clay)
5.0
100
80
4.0
10
0.1
1
10
100
1000
80
40
20
0
0.001
0.01
0.1
60
工区Ａ
工区Ｂ
工区Ｃ
40
Significant variation in
consolidation parameters
（CH）
（CL）
○ 工区Ａ
□ 工区Ｂ
◇ 工区Ｃ
20
1
(mm)
Particle 粒径　diameter
(mm)
(b)
10000
p (kPa)
100
10
（MH）
Æ Feedback based on the
measured settlement
and pore water
pressure is necessary.
（ML）
0
0
20
40
60
80
100
120
140
w L (%)
Liquid limit
wL (%)
液性限界
間隙比 e
60
Plasticity
indexI pIp
塑性指数
(%) (%)
通過質量百分
Percentage
finer分率　bby weight
100
1000
3.0
2.0
1.0
対象となる応力範囲
0.0
0.1
1
10
100
1000
10000
圧密圧力 p (kPa)
A study on the drain spacing based on the allowable residual settlement
2002
2003
2004
2005
A study on the drain spacing based on the allowable residual settlement
(with preloading)
0.5
5
2002
2003
2004
2005
2006
2007
Settlement (m)
7
1.0
Without preloading & drains
Preloading (7 m), without drains
Preloading (7 m) & Drains ([email protected] m)
Open
8
6
1.5
00
0.0
Drain spacing
0.1
0.2
0.3
Open
Settlement (m)
2007
2006
0.0
9
Open
Ground level (m)
10
0.4
0.8 m
1.0 m
1.2 m
1.4 m
1.6 m
2.0
50 m
40 m
2.5
0.5
0.6
Drainage
Facilities construction
0.7
3.0
Facilities’
construction
0.8
0.9
1.0
Tokyo International Airport (Haneda Airport)
-Reclaimed with dredged clay in ultra-soft state.
-Self-weight consolidation was not calculated.
-Consolidation after the drain installation was predicted by
Terzaghi’s and Barron’s linear consolidation theory.
New Kitakyushu
y
Airport
p
-Reclaimed with dredged clay in ultra-soft state.
-Self-weight consolidation was calculated by non-linear theoretical
equation before the drain installation.
-Then, consolidation was predicted by Terzaghi’s and Barron’s
linear consolidation theory.
Central Japan International Airport
-Shallow water depth. Shallow bearing layer.
Æ Small residual settlement after the inauguration.
-Approx. 1/3 (north) of the man-made island was
reclaimed with cement treated dredged clay (pneumatic
flow mixing method)
Æ Short construction period because consolidation is
not required. However, should be concerned with
deterioration in quality if soil is acidic/organic.
-Approx. 2/3 (south) of the man-made island was
reclaimed with mountain sand.
Æ Offshore side with thick soft clay layer was improved
by sand drains to accelerate consolidation.
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2008/10/9
Pneumatic flow mixing method
Cementt ttreated
C
t d clay
l
(Pneumatic flow
mixing method)
Mountain sand
(well grained)
Pressured air
Air
Mud
Pressured mud Plug flow
Cement fluid
Mixture
Kansai International Airport
-Deep sea. Thick clay deposits.
-Residual settlement is caused in the deep Pleistocene
layers. Æ Uncontrollable!
ÆMeasurement of stratified settlement & pore
pressure to readjust
p
j
the calculated settlement.
-To avoid differential settlement
-Settlement was uncontrollable because of large depth.
Thus, the time lag of the construction was minimized
along the runway (4,000 m).
Installation of
sand drains
Reclamation from
belt conveyer barge
Passive countermeasures for differential settlement
Apron of the Tokyo International Airport
Lift-up method:
To adjust for the differential settlement, which causes
unacceptable slopes, the prestressed concrete slab is jacked up and
the clearance gap is grouted.
Reclamation from
bottom open barge
Terminal building of the Kansai International Airport
Jack-up system:
1st
2nd
phase
phase
Grain size < 300 mm
To adjust for the differential settlement of the terminal building,
the column is jacked up and the clearance is inserted by steel
plates.
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2008/10/9
Lift-up method (Tokyo International Airport)
Lifting up the PC slabs (Tokyo International Airport)
PC slab
Asphalt treated layer
Jacking up
Road bed of crushed stones
Subgrade sand
Double Sheets
Socket for jack
Gro ting
Grouting
Settlement
Lift-up jack
Jack up system in the terminal building
(Kansai International 関西国際空港
Airport)
Further expansion project
Structure of D-runway
Column
Shear key
A.P. +7.3 m
Jack
A.P. +15.0 m
A.P. +13.7 m
A.P. +17.1 m
Bridge section
(1,100 m)
Change
Reclaimed aria
(2,020 m)
-D-runway Æ Hybrid structure of “reclamation” & “bridge”
Filler plates (steel)
-River mouth of the Tama river Æ Bridge structure to ensure the flow rate
-Runway length 2,500 m (Island length 3,120 m)
-Water depth A.P. –12 to –20 m
Airport capacity is almost saturated
Contract for D-runway construction
Æ Further expansion project to meet strong social demand
6,390万人
63.9M
67.4M
6,740万人
Further
expansion project
【羽田空港再拡張概略図】
Contract
For D-runway
For a normal work
Specifications
Required performance
(Contractor presents a proposal)
Drawing &
specifications
6,000
60M
5,000
50M
40M
4,000
3 30M
3,000
000
20M
2,000
10M
1,000
00
Design risk
By contractor
By client
Ordering
method
Blanket order of design and construction work:
-Basic &execution designs
g are done byy
contractor.
-New technological development can be
proposed by contractor.
-Construction & maintenance/management
costs calculated in the design process are
guaranteed by contractor.
Separated order for
design
g &
construction work
17
’1
7
12
’1
2
’0
1
’0
2
’0
3
’0
4
’0
5
’0
6
’9
6
’9
7
’9
8
’9
9
’0
0
’9
4
’9
5
94 96 98 00 02 04 06
C-runwayy (3,000 m)
Terminal 2
）
万
人
7,000
70M
Terminal 1
A-runway (3,000 m)
（
国
内
線
旅
客
数
8,000
80M
International Terminal
Passengers foor domestic flights
Construction was started on 30th March 2007
-Joint Venture Group for 5 different categories of work was required
-Contract amount = 598,500,000,000JPY or 5,700,000,000USD (tax included)
Year
Maintenance & For 30-years after inauguration
management
Today
296,000 flights/year
(30 flights/h)
Future
407,000 flights/year
(40 flights/h)
Capacity
Æ 1.4 times
Closing bid
Not included
The lowest amount for design, construction work, The lowest amount for
& 30-years maintenance/management
the construction
8
2008/10/9
A.P. (m)
-10
Structure of D-runway
Å South-West (Tama River)
A-9
-15 A-8
Reclamation
-30
Ylc (Ac2)
Nas1 (Ds1)
Nas1 (Ds1)
Nac1 (Dc1)
Nac1 (Dc1)
Toc3 (Dc5)
Toc3 (Dc5)
btg (Dg1)
TB10～18 ((V. ash))
Toc2 (Dc4)
Tos2 (Ds4)
T 3 (Dg4)
Tog3
(D 4)
Edc1 (Dc6)
Eds1 (Ds6)
Eds1 (Ds6)
0
50
Pile structure
Piled structure
Jacket structure
Connecting taxiway
SD
0
200
100
-50
-30
130
20
-60
100
-70
-80
①-H
①
②
③1
③2高Cc
③2低Cc
③3
④
⑤
-90
-100
-110
100
200
300
400
25
-40
①－H
①1
①2
①3
②1
②2
②3
②4
③1
③2高Cc
③2低Cc
③3
OCR＝ 1.3， m＝0.3
OCR＝ 2.5， m＝0.2
-50
-60
-70
Bottom open barge
Grab crane
Tremie
-20
-40
-50
-60
-70
①1
①2
①3
②1
②2
②3
②4
③1
③2高Cc
③2低Cc
③3
OCR=1.3
OCR=2.5
σ’v0
-30
-40
-50
-60
-70
-80
-90
-90
-90
Bottom open barge
Pneumatic flow mixing
Plant
Pump
Placing
Pneumatic flow
Plant Air pump
Belt conveyer
Grab crane
Bulldozer
vibration roller
Belt conveyer
Vibration roller
Bulldozer
Dump track
Grab crane
Backhoe
Crane barge
Crane barge
Crane barge
Asphalt finisher
Consolidation settlement in design
安全区域
2020
盛土天端(m)
Ground elevation (A.P. m)
1500
Elevation
A.P. (m)
30
30
20
20
10
10
00
-10
–10
-20
–20
沈下量(m)
1000
SCP
Estimated settlement
Settlement (m)
400
① -H
①1
①2
①3
②1
②2
②3
②4
③1
③ 2高 Cc
③ 2低 Cc
③3
OCR＝ 1.3，m＝0.3
OCR＝ 2.5，m＝0.2
-80
Dump track
00
11
22
33
44
55
66
77
88
300
-30
Dump track
Grab dredging
200
500
Reclamation procedures (contn’d
(contn’d))
SD
Tremie
100
0
-80
Ruble filling
Grab crane
0
2
Consolidation
yield
stress
pc (kN/m2)
圧密降伏応力
)
p c (kN/m
-20
Elevation
A.P. (m)
標高A.P.(m)
40
-40
Elevation
A.P. (m)
標高A.P. (m)
標高A.P.(m)
Elevation
A.P. (m)
Beam structure
Reclamation procedures
SCP
150
2)
2
cu from
UU test u c(kN/m
)
UU試験によるc
u (kN/m
-20
-30
Ｄ滑走路プロジェクト推進室
100
-20
Pavement
Eds1 (Ds6)
Edc1 (Dc6)
Edc1 (Dc6)
Eds1 (Ds6)
2)
2
UC test cuu (kN/m
(kN/m
cu from
一軸圧縮試験によるc
)
Water
content
w (%)
自然含水比
w (%)
n
D-runway
Tog2 (Dg3)
Tog3 (Dg4)
⑤
-90
Cross section along the runway
Toc1 (Dc3)
④ Tos3 (Ds5)
Edc1 (Dc6)
-95
Toc1 (Dc3)
Tos1 (Ds3)
Toc1 (Dc3)
Toc3 (Dc5)
Tog3 (Dg4)
-100
Nas2 (Ds2)
Nac2 (Dc2)
③
Toc1 (Dc3)
Tos1 (Ds3)
Tos1 (Ds3)
-85
Steel
Pipe Piles
Nas2 (Ds2)
Nac2 (Dc2)
Nas2 (Ds2)
Nac2 (Dc2)
Nas2 (Ds2)
Nac1 (Dc1)
Nac1 (Dc1)
Nac2 (Dc2)
Tos1 (Ds3)
Toc1 (Dc3)
-85
Jacket
structure
Concrete slab
N値
50
Ys2 (As2)
Nac1 (Dc1)
Nas1 (Ds1)
Nac2 (Dc2) UG (V. ash)
Tos1 (Ds3)
-70
-75
Bridge (long span)
0
Ylc (Ac2)
②
Nac1 (Dc1)
Nas1 (Ds1)
-65
Bridge (short span)
N値
50
Nas2 (Ds2)
-60
Bridge
Nas1 (Ds1)
Nac1 (Dc1)
Nac1 (Dc1)
-50
Nas1 (Ds1)
Previous Airport
Reclamation
0
Yuc (Ac1)
Yuc (Ac1)
Ylc (Ac2)
-45
Connecting
taxiway
A-1
A-2
Ys1 (As1)
Sand Drains
Pavement
North-EastÆ
A-13
N値
0 50
-35
-40
Concrete slab
A-12
N値
0 50
①-H
Hc
①
Yuc (Ac1)
Filling
Sand Compaction Piles
A-11
N値
0 50
A-10
N値
0 50
N値
50
0
-25
Pavement
Wave-dissipating blocks
Rubble stones
N値
50
Elevation
標高A.P.
A.P.
(m) (m)
Mild slope rubble seawall
0
-20
盛土天端（沈下無し）
Total thickness
Airport
open
工事完了時計画地盤高
100計画最低地盤高
years aft.
Elapsed time
1010
13.585
13.000
7.749
Bridge
Reclamation
6.858
15.000
13.900
17.100
1515
Settlement incl
盛土天端（沈下あり）
安全区域
18.000
55
1次圧密のみ
Primary only
Secondary incl
全沈下量（2次圧密含む）
0
7.9 240.0
2.1
60.0
1,250.0
446.6
803.4
15.7
60.0 178.697 10.0
37.678 7.875
AP±0(m)
Residual settlement
approx. 0.90m
600 kN/m2
Water depth –20 m
U = 80%
Construction
start
250 kN/m2
S=3m
Nearly equal to
Kansai Int. Airport
Construction Inauguration
finished
S = 6.8 m
30 years aft.
S = 7.7 m
100 years aft.
S = 7.9 m
S=8m
9
2008/10/9
Cross section of the mild slope rubble seawall
Deformability for the settlement Æ mild slope rubble seawall
Technology for seawall construction
-Thick soft clay deposit and large water depth
-Very high earth fill in a short construction period (35 month)
Concept in the design
(1) Sand Compaction Piles with a low displacement ratio (30%)
Æ to improve the stability and accelerate the consolidation
(2) Light weight soil (Air-foam treated soil & pneumatic mixed treated soil)
Æ to assure the stability of the seawall
Utilize as a material
Pneumatic flow mixing method
Approx. 5,400,000 m3
Dredged clay from the shipping route
Utilize as a material
filling
Clay layer
Pneumatic mixed clay
Rubble
A.P.-12.0～-20.0m
Sand mat
Displacement
Sand Drains
Sand Compaction Piles (30%)
(1)-C
(2)-C
A.P.-52.0～-62.0m
Sand layer
Displaced by
heavy material
Φ2,000（3ｍ×3ｍ）
Φ400（2.5ｍ×1.6ｍ）
Treated soil (filling by
lightweight soil)
Improve the
stability
KIX-1
KIX-2
HND
Clay thickness
35.5 m
43 m
42 m
Construction
period
30 month
26 month
19 month
Consolidation
period
4 month
4 month
2 month
Degree of
consolidation
80%
80%
50%
Pressured mud Plug flow
Mixture
Utilization of RI-CPT
Staged construction with data measurement
CPT
RI-CPT
to monitor the consolidation process
-shear strength
Inclinometer
Casing for boring
& CPT
and
Settlement gauge
(rod type)
Landfill 2
Temporal dike 2
Landfill 1
-bulk density
Sand drains
Settlement
gauge
(magnetic type)
バックグラウンド
（ＢＧ）［自然γ
γ
γ
Sand 1
Sand drains
γ
γ
A.P.-12.0～-20.0m
γ
γ線検出器
NaI シンチレータ
u: pore pressure
(1)-C
fs: 周面摩擦
Sand 2
RI-CPT
Temporal dike 1
RI-CPT
Temporal dike 2
RI-CPT
(2)-C
ｕ :間隙水圧
A.P.-52.0～-62.0m
Sand layer
Temporal dike 1
Sand 2
Sand 1
γt: bulk density
Settlement
gauge
(pressure type)
fs: sleeve friction
Clay layer
Cement fluid
Air
Mud
Pressured air
Φ2,000（3ｍ×3ｍ）
Φ400（2.5ｍ×1.6ｍ）
qt: tip resistance
Landfill 1
qc:先端抵抗
RI-CPT
Landfill 2
10
2008/10/9
Impediment rate of river flow < 8%
Bridge section
Reclamation
Span length > 25 m
(average > 50 m)
Impediment rate of river flow < 8%
C-runway
Taxi
Bridge section
Bridge
A-runway
Width: 520 m
Length: 1,100 m
Æ Area: 52 ha
Water depth: 14–19 m
H.W.L. (river)
A.P. +3.8 m
River cross section
River bed
A.P. –3.7m
Sea bed
A.P. –17m
Corrosion prevention technology
—toward a long-term durability (100 years)—
Bridge –Jacket type–
Asphalt pavement
Concrete slab
Titanium cover plate to protect from
Closed system (cell)
to prevent erosion
Steel beams
Stainless steel lining
salt corrosion 570,000 m2
(it can also be used as a scaffold)
Dehumidification system to maintain
the relative humidity less than 50% in
the room of the girder
(dehumidifier, fan, duct)
Cover plate
Cover-plate (Titanium)
Seawater-resistant stainless steel lining
Electrolytic protection
Jacket structure
198 Jackets
Standard size: 63 m (L), 45 m (W), 32 m (H), Weight: 1,300 t
1,165 Steel pipe piles
Maximum size: 1,600 mm (Dia.), 90 m (L), Weight: 90 t
to protect from salt corrosion 520,000 m2
(intertidal zone + splash zone)
Titanium cover plate
Seawater-resistant stainless steel lining
Dehumidification system
11
2008/10/9
Clearance between the decks
A t
Automatic
ti welding
ldi machine
hi
Segment with temporal joints (before welding)
Welded joint
Interface between the bridge and reclaimed island
Interface between the bridge and reclaimed island
Buffer structure
AP+13.7m
girder
Air--foam treated soil (Lightweight soil)
Air
Cement treated soil (pneumatic mixing)
Reclamation section
Ruble mound
8
AP–18m
Bridge section
Slit columns
AP–36m
(1)-C
Fill for partition
SCP
(30%)
SCP (70%)
(2)-C
Cellular seawall
(Well foundation)
AP–60m
(3)-S
Rubble mount
(counter weight)
Cellular seawall (well foundation)
of steel-pipe-sheet-pile
Technology to lighten the backfill
Horizontal displacement of the cellular seawall
(well水平変位
foundation)
(cm)
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
—Lightweight soil —
Air-foam treated lightweight soil
Approx. 900,000 m3
Open
20
500 mm
100 y aft.
10
0
-10
①-H
①-Ｃ-1
① Ｃ 2
①-Ｃ-2
-20
標高AP (m)
Elevation
AP. (m)
A
Tremie
-30
-40
Air foam
Lateral
movement
Mixing plant for
cement and air-foam
Strain gauge
(optical fiber)
Strain gauge
Inclinometer
GPS
Cross section of the interface
-50
-60
90% before
open
井筒下端
Screening
Slurry tanks
②-Ｃ
③-Ｓ
-70
③-Ｃ-1
-80
⑤
-90
Horizontal displacement
-100
Appox. 2 m in L2 earthquake
12
2008/10/9
Buffer structure
—Expansion joint—
History of reclamation technology adopted in
man-made islands for airport construction
Rolling plate
Reclamation with ultra-soft dredged clay
-Tokyo International Airport (Haneda Airport)
-New Kitakyushu Airport
Reclamation with cement-treated clay
-Central Japan
p International Airport
p
Fixed plate
±600 mm
-A part of
Tokyo International Airport (4th-runway)
Reclamation with mountain sand
-Kansai International Airport
渡り桁
-A part of
Central Japan International Airport
Tokyo International Airport (4th-runway)
すべり支承
Hybrid structure of landfill and bridge
-Tokyo International Airport (4th-runway)
接続部上部構造
Thickness (m)
Concrete
台座コンクリ
(Knock（ノックオフ部
off structure)
Osaka
Kansai International Airport
The first phase of the Kansai International Airport Project, which was inaugurated in
Settlement (m)
Tokyo
1987/9 1989/9 1991/9
40
30
20
10
Landfill
0
0
1
2
3
The average water depth was 18 m, and the
1
The average water depth was 19.5 m, and thick clay layers up to 400 m in depth alternated with
some sandy layers.
The incremental consolidation pressure reached 600 kPa with reclamation.
There are three main approaches for both the practical and
theoretical evaluations of the consolidation settlement, and these can be
listed as follows:
1999/9
2001/9
2003/9
2005/9 2007/9
height
1st phase
Holocene layers,
improved by
sand drains
ÆAirport open
7
0
Settlement (m)
The second phase with a parallel runway is operational since August 2007.
1997/9
5
6
The second phase of the airport has also been constructed as a man-made island of
approximately 545 ha.
1995/9
4
September
S
b 1994
1994, iis a large
l
man-made
d island
i l d off
approximately 510 ha located 5 km offshore in Osaka Bay.
incremental consolidation pressure
reached 450 kPa with reclamation.
1993/9
Pleistocene layers,
without soil
improvement
2
3
4
5
6
7
8
9
1987/9 1989/9
1991/9
1993/9
1995/9
1997/9
1999/9
2001/9
2003/9
2005/9 2007/9
Basic isocache concept
We use very simple equations proposed by Leroueil et al. (1985).
The isotache concept is only applicable to visco-plastic deformation, which is
the total deformation less the elastic deformation.
(i) The coupling of Terzaghi’s one-dimensional consolidation theory and the constant
Cα concept.
(ii) The end of primary consolidation (EOP) concept (Mesri and Choi, 1985) and the
constant Cα/Cc concept (Mesri and Castro, 1987).
For clarity, we employ the εvp – log p' relationship, where εvp is the visco-plastic strain,
which is defined as the difference between the total strain ε obtained from the consolidation test
and the elastic strain εe.
We then use the following equations.
(iii) The isotache concept (Šuklje, 1957)
ε vp = ε − ε e
: Visco-plastic
p
strain
In this paper, we propose a simplified model of the isotache concept and
apply it to the long-term consolidation of Osaka Bay clay;
p′
= f (ε vp )
p c′
: εvp – p'/p'c relationship
Reference compression curve
Å CRS test:
consolidation test in a
constant rate of strain
pc′ = g (ε& vp )
: p'c – ε
&
Å LT test:
long-term consolidation
test
we then tabulate
the isotache parameters introduced in the model.
vp
relationship
13
2008/10/9
Simplified model of the isotache concept
N
′
p′ − pcL
= c1 + c2 ln ε&vp
ln c
′
pcL
Here, c1
When
and c2 are constants and p'cL is the lower limit of p'c.
ε&vp decreases to zero, p'c converges to p'cL.
The parameter c1 is equal to ln{(p'c – p'cL)/p'cL} at ε&vp = 1,
i.e. it represents the relative position of the log p'c – log ε&vp curve.
Clay samples
The parameter c2 represents the level of strain rate dependency.
dependency
The compressibility which reflects the level of developed skeletal structure is
represented by the reference compression curve.
εvp–log p' relationship
Consequently
-the reference compression curve and
-three isotache parameters (c1, c2 and p'cL)
are required in the proposed isotache model.
CRS test
Reference compression curves
εvp – log p' relationship
0.0
Visco-plastic strain εvp
0.3
0.4
Ma12
Ma11
Ma8
Ma7
Ma4
Ma13Re
Yes
Yes
Yes
Yes
Yes
Yes
No
Reconstituted
No
No
No
No
No
No
Yes
Depth (C.D.L.–m)
39
61
109
208
223
264
30–40
Overburden effective stress σ'v0 (kPa)
88
286
619
1348
1457
1802
(98)
Consolidation yield stress p'c (kPa)
122
439
737
1698
1887
2512
134
Overconsolidation ratio OCR
1.39
1.53
1.19
1.26
1.30
1.39
(1.37)
Soil particle density ρs (g/cm3)
2.66
2.66
2.67
2.72
2.70
2.67
2.70
Liquid limit wL (%)
75.1
102.6
88.9
91.8
100.4
93.6
91.3
Plastic limit wP (%)
31.9
40.8
34.4
35.8
37.8
35.3
30.3
Plasticity index Ip
43.2
61.8
54.5
56.0
62.6
58.3
61.0
Natural water content wn (%)
62.0
83.8
55.4
49.9
49.0
50.6
71.5
Sample
Ma13
Ma12
Ma11
Ma8
Ma7
Ma4
Ma13Re
0.2
Ma13
Undisturbed
Long term consolidation test (LT test)
p′
= f (ε vp )
p c′
0.1
Layer
Pressures for preliminary consolidation （kPa）
24 hours incremental loading
7 days loading
at σ'v0
Pressures for long term
consolidation （kPa）
Ma13
10Æ29Æ
88Æ
98, …, 353 & 412
Ma12
39Æ79Æ157Æ
294Æ
333, …, 882 & 1370
Ma11
39 (2 hours)Æ
628 (24 hours)Æ
647, …, 1000 & 1569
Ma8
39 (2 hours)Æ
1373 (24 hours)Æ
1412, …, 1785 & 2040
Ma7
39 (2 hours)Æ
1491 (24 hours)Æ
1549, …, 1922 & 2177
Ma4
39 (2 hours)Æ
1863 (24 hours)Æ
1902, …, 2452 & 3138
88Æ
118, …, 343 & 412
Ma13Re 10Æ29Æ
OC
0.5
0.1
1
ÆÆÆÆÆÆ
NC
10
p'/p'c
p' – εvp – ε& vp
0.0
relationship
& εvp– log p' relationship Æ p'c – ε& vp
relationship
2
3x10
−5
p = 333 kPa
p = 373 kPa
p = 412 kPa
p = 451 kPa
p = 490 kPa
p = 529 kPa
p = 608 kPa
p = 686 kPa
p = 882 kPa
p = 1370 kPa
0.2
0.3
-3
10
-2
10
-1
10
EOP
3x10
p'c / p'c0LT
Strain ε
S
0.1
−6
3x10
−7
3x10
−8
−9 −1
3x10 s
= ε&vp
0.8
(b) Ma12
0.7
σ'v0 = 286 kPa, p'c = 439 kPa
0
10
1
10
2
10
3
10
4
10
LT test
(p = 608 kPa)
(p = 686 kPa)
(p = 882 kPa)
(p = 1373 kPa)
Eq. (8)
Regression curve
1
p'cL/p'
/ c0LT = 0.55
0.9
5
10
6
10
Time t (min)
Æ p' – ε – ε& vp relationship
(b) Ma12
0.6
1E-11 1E-10 1E-9 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3
-1
p'c0LT is defined as the p'c corresponding
to an ε& vp value of 3.3×10–6 s–1 on the
fitting curve obtained from LT test.
Strain rate ε･vp (s )
14
2008/10/9
0.0
－
p'c0CRS (kPa)
122
439
737
1698
1887
2512
134
p'c0LT (kPa)
133
447
814
1736
1811
2420
150
p'cL (kPa)
73
246
447
955
995
1333
83
p'cL/p'c0LT
0.55
0.55
0.55
0.55
0.55
0 55
0.55
0.55
c1
1.11
1.09
1.13
1.09
1.05
1 07
1.07
1.01
c2
0.103
0.103
0.105
0.102
0.099
0 101
0.101
0.097
′
p′ − pcL
= c1 + c2 ln ε&vp
ln c
′
pcL
0.2
εvp – log p'
CRS test
0.3
0.4 (b) Ma12
−8 −1
3.3x10 s
0.5
0.1
0.0
1
p'/p'c
2
1
0.9
(b) Ma12
10
LT test
(p = 608 kPa)
(p = 686 kPa)
(p = 882 kPa)
(p = 1373 kPa)
Eq. (8)
Regression curve
p'cL/p'c0LT = 0.55
p'c – ε& vp
p
LT test
0.8
0.7
(b) Ma12
0.6
1E-11 1E-10 1E-9 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3
-1
Strain rate ε･vp (s )
Visco-plastic strainn εvp
σ'v0 (kPa)
88
286
619
1348
1457
1802
p'c / p'c0LT
Sample
Ma13
Ma12
Ma11
Ma8
Ma7
M 4
Ma4
Ma13Re
Visco-plastic strain εvp
0.1
Æ p'c – ε& vp relationship
from isotache concept
0.1
−5
3x10 s−1
from LT tests
−5
0.2
0.3
2
2x10
3x10
−6
3x10
−7
3x10
−8
3x10
−9
3x10
−6 −1
3x10 s
−1
s
−7 −1
3x10 s
−1
s
−1
s
−1
s
−1
s
−8 −1
3x10 s
−9 −1
3x10 s
3
10
Consolidation pressure p' (kPa)
3
2x10
Conclusions
The model proposed in this study is very practical because the reference
compression curve and the isotache parameters (pcL, c1, and c2) can be evaluated from a
minimum of one CRS test and one LT test. The LT test should be conducted to cover the
normal consolidation range.
This study showed that the proposed equation is widely applicable to the
Osaka Bay clay.
The p'cL was evaluated to have a common value of 0.55 × p'c0 for the clays
examined where p
examined,
p'c0 is defined as pp'c at a value of 3.3
3 3 × 10–66 s–11.
When p'cL = 0.55 × p'c0 was used,
the other parameters c1 and c2 were also evaluated in narrow ranges
as 1.08 ± 0.04 and 0.101 ± 0.003, respectively.
This implies that the isotache parameters p'cL, c1, and c2 can be
commonly determined for the Osaka Bay clays retrieved from the Kansai
International Airport.
15

Large man-made airport islands in Japan

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Monatsblatt # 47 vom 30. Oktober 2015