Proceedings of Indian Geotechnical Conference
December 15-17,2011, Kochi (Invited Talk-7.)
NEW CHALLENGE IN D-RUNWAY CONSTRUCTION OF TOKYO HANEDA AIRPORT
Yoichi Watabe, Port and Airport Research Institute, Yokosuka, Japan, watabe@ipc.pari.go.jp
Takatoshi Noguchi, Kanto Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism, Japan
ABSTRACT: Tokyo International Airport (Haneda Airport) has been developed by land reclamation. A new runway, named
“D-runway,” was constructed from March 2006 to October 2010. Because some part of the D-runway is located in a river
mouth, a hybrid structure consisted of piled pier and reclamation fill was adopted. To overcome the difficulties in construction
on soft clay deposit, it adopted various technologies in design and construction. This paper describes about the outline of the
project, ground investigation, and designing of the D-runway structure, from a view point of geotechnical engineering.
INTRODUCTION
Tokyo International Airport (Haneda Airport) has been
developed by reclamation. The offshore expansion project
started from 1984 was an epoch-making project, in which
airport island was constructed from a dredged clay disposal
facilities in ultra-soft state (Katayama, 1991). Recently, The
fourth runway named “D-runway” has been newly
constructed (Photo 1, Fig.1). The D-runway started its
operation in October 2010 on schedule. This paper describes
about the outline of the D-runway project, soil stratigraphy,
and designing of the manmade island, from a view point of
geotechnical engineering.
The geological cross-section in the D-runway direction is
shown in Fig.2. Soil layers are named reflecting the
geological history; i.e. Y (Yurakucho layer), Na (Nanago
layer), To (Tokyo layer), and Ed (Edogawa layer). Subscripts
c, s, and g represent clay, sand, and gravel layers,
respectively. The interface between Yuc and Ylc is almost
horizontal; however, lower boundary of Ylc is slightly deeper
around the south-west end of the D-runway (side of the
Tamagawa River). Most part of Na layer, Nac and Nas
deposited alternately. The Na layer at A-13 deposited deeper
and thicker than that at others, indicating that the Nac at A-13
deposited in an eroded valley in Tokyo layer.
OUTLINE OF THE D-RUNWAY PROJECT
The D-runway is located 600 m offshore from the previous
airport island. In the area inside the river mouth of the Tama
River, a pier structure with an impediment rate of river flow
less than 8% is adopted to ensure a sufficient flow rate during
times of floods. Therefore, the D-runway is a hybrid structure
of piled pier and reclamation fill. The length of the D-runway
is 2500 m. The elevation at the offshore end of the D-runway
is required to be higher than A.P. +17.1 m, which is
extremely higher than ordinal manmade island. Here,
elevation ±0 in A.P. corresponds to +1.134 m in T.P.
STRUCTURE OF THE D-RUNWAY
Reclamation Section
Seawall type
The reclamation section was constructed on a soft clay
seabed as a high embankment whose thickness is
approximately 41 m from seabed to the top. Because of
C-runway
3,000m
A-runway
3,000m
New control
tower
Apron
Terminal
2
Garden
Terminal
1
New international
area
Parking
New runway
(D-runway)
2,500m
Passenger terminal
Cargo terminal
Photo 1. A scene of the D-runway construction taken on 18
July 2010.
41
Fig.1. Site plan of the D-runway and previous airport
facilities.
Yoichi Watabe & Takatoshi Noguchi
A.P. (m)
-10
Å Tama River side (SW)
A-9
-15 A-8
-20
N-value
0 50
0
A-10
N-value
0 50
N-value
50
Jonan Island side (NE) Æ
A-12
N-value
0 50
A-11
N-value
0 50
A-13
N-value
0 50
Hc
A-1 Nvalue
0 50
A-2
N-value
0 50
-25
Yuc (Ac1)
Ys1 (As1)
-35
-40
Ylc (Ac2)
-45
Nac1 (Dc1)
-50
Nas1 (Ds1)
-60
-65
-70
-75
-85
Nas1 (Ds1)
Nas1 (Ds1)
Nac1 (Dc1)
Yuc (Ac1)
Yuc (Ac1)
(1)
-30
Ylc (Ac2)
Ylc (Ac2)
Nas1 (Ds1)
Nac1 (Dc1)
(2)
Ys2 (As2)
Nac1 (Dc1)
Nas2 (Ds2)
Nac2 (Dc2)
Nas2 (Ds2)
Nac2 (Dc2)
Nas2 (Ds2)
Nac1 (Dc1)
Nac1 (Dc1)
Nac1 (Dc1)
Nac1 (Dc1)
Nas1 (Ds1)
Nas2 (Ds2)
Nas2 (Ds2)
Nas1 (Ds1)
Tos1 (Ds3)
Nac2 (Dc2) UG (ash)
Tos1 (Ds3)
Toc1 (Dc3)
Toc3 (Dc5)
Toc3 (Dc5)
Nac2 (Dc2)
Tos1 (Ds3)
Toc1 (Dc3)
Tos1 (Ds3)
btg (Dg1)
(3)
Edc1 (Dc6)
TB10䌾18 (ash)
Toc1 (Dc3)
Toc2 (Dc4)
Tos2 (Ds4)
Tog3 (Dg4)
-90
Tog2 (Dg3)
Tog3 (Dg4)
(5)
-85
Edc1 (Dc6)
Eds1 (Ds6)
Eds1 (Ds6)
Edc1 (Dc6)
Edc1 (Dc6)
Eds1 (Ds6)
-95
Toc1 (Dc3)
Tos1 (Ds3)
Toc1 (Dc3)
(4) Tos3 (Ds5)
Toc3 (Dc5)
Tog3 (Dg4)
Nac2 (Dc2)
Eds1 (Ds6)
-100
Fig.2. The geological cross-section in the D-runway direction in original plan.
Parapet
Block
Wave-dissipating blocks
Cover stones
Sand 1
Rubble
Cement treated soil (pneumatic mixing)
Partition 2
Rubble
Sand (counterweight)
Mound
Mound
Replaced sand
SCP 60%
Partition 1
Sand (cover)
SCP 60%
Sand
(1)-C-1
SCP 30%
(1)-C-2
SD
(2)-C
ႇᄖ஥
ጯ
⼔
ᴺ
✢
ⓨ
ᣉ
᷼
⸳
↪
࿾
⇇
Ⴚ
ႇౝ஥
(2)-S
(2)-C
(3)-S
Fig.3. A typical cross-section of the mild slope rubble seawall (general seawall section).
30% (low replacement ratio SCP) was utilized to improve the
stability as a composite ground and to accelerate the
consolidation as drainages. SCP pile arrangement was 3.0 m
× 3.5 m.
consolidation settlement, the thickness is larger than the total
of the water depth and elevation of the runway. Incremental
consolidation pressure applying to the seabed surface by this
reclamation reached up to approximately 550 kN/m2. This
consolidation pressure, equivalent to that at the second phase
island of the Kansai International Airport, is the largest in the
history of the Tokyo Bay.
In addition, soft clay seabed in front of the seawall was
dredged and replaced by sand as counterweight. The dredged
clay was cement treated and backfilled as lightweight soil.
These two technologies of counterweight and cemented
lightweight soil contribute to improve the stability of the
seawall.
A mild slope rubble seawall was adopted for the general
seawall section (4144.1 m), and a gravity type caisson
seawall was adopted for the approach light seawall (100.2 m)
and tentative quay wall for the construction (221.0 m).
Inside the Reclamation Fill
Inside the reclamation fill, the soft ground was improved by
sand drains (SD), to decrease residual settlement during the
in-service period by accelerating the consolidation behavior.
To achieve a degree of consolidation of 80% in Yuc layer
(deposited up to A.P. –35 m with a coefficient of
Mild slope rubble seawall
The mild slope rubble seawall was utilized to the general
seawall section because of flexibility for both settlement and
lateral movement. A typical cross-section is shown in Fig.3.
Sand compaction pile method with a replacement ratio of
42
New challenge in D-runway construction of Tokyo Haneda Airport
Reclamation
Pire
᪋ᯅㇱ
Expansion device
(Rolling leaf)
Beam
ᷰࠅᩴ
Columns
#2
Pavement and
Cover soils
Asphalt
treated layer
િ❗ⵝ⟎
ࡠ࡯࡝ࡦࠣ࡝࡯ࡈ࠲ࠗࡊ
Airfoam treated soil 2 (10.0 kN/m3)
ࠕࠬࡈࠔ࡞࠻቟ቯಣℂ
Airfoam treated soil 1 (11.5 kN/m3)
Cover stones
*9.#2
.9.#2r
(1)-H
(1)-C-1
#2
#2
(1)-C-2
SCP 60%
SCP 30%
*
%
#2
Fig.4. Contours of the predicted residual settlement in 100year in-service period.
#2
(2)-C-1
%
シ㊂ᷙวಣℂ࿯
ǫM0㨙
਄ㇱ᭴ㅧ
Cement treated
soil 2 (14.0 kN/m3)
Rubble mound
ⵍⷒ⍹
SCP78%
Cement treatedシ㊂ᷙวಣℂ࿯
ǫM0㨙
soil 1 (14.0 kN/m3)
#2
ਛ⹣
೨㕙ࡑ࠙ࡦ࠼
SCP 30%
ᝥ⍹
#2
5%2ᡷ⦟
5%2ᡷ⦟
5%2ᡷ⦟
Steel
pipe
piles
▤ਛᷙว࿕ൻಣℂ࿯
ǫM0㨙
Sand
Sand mat
(1)-H
▤ਛᷙว࿕ൻಣℂ࿯
ǫM0㨙
(1)-C-1
଻⼔⍾
(1)-C-2
ࠨࡦ࠼ࡑ࠶
*
5%2ᡷ⦟
%
#2
(2)-C-1
%
㍑▤⍫᧼Ǿ
%
(3)-S
#2
(3)-C-1
5
(3)-C-1
#2
5
(5)
(5)
#2
#2
%
(3)-S
#2
%
%
Fig.5. Cross-section of the joint structure between the
reclamation and pier sections.
Piled Pier Section
In the piled pier section, to conduct the construction within
the short period, prefabricated jacket structure was adopted.
A jacket unit is composed of upper steel girder and lower
steel pipe legs reinforced by truss structure, as shown in
Photo 2. Its standard dimension is 63 m in length, 45 m in
width, 32 m in height, and 1300 t in mass. Total 198 units of
jacket were installed for the main body of the D-runway.
Photo 2. A scene of installation of a jacket unit.
consolidation cv of approximately 100 cm2/day) at 4 months
after a staged filling, the arrangement of SDs with 400-mm
diameter were set to be 2.5 m × 1.6 m. The SDs were
installed up to A.P. –35.5 m to A.P. –37.5 m corresponding to
the depth of Ylc layer. The SD installation was conducted
after placing the 1.5-m thick sand mat drainage (hydraulic
conductivity is higher than 1 × 10–4 m/s). After the SD
installation, 2.5-m thick sand layer (hydraulic conductivity is
higher than 1 × 10–5 m/s) was placed for SD head protection.
In the assembling procedure of the jacket structure (Photo 2),
six steel pipe piles were first driven to the ground, then the
prefabricated jacket unit were set by inserting the pile heads
into the pipe legs, and then the clearance between the pile
heads and legs were grouted by mortar. After assembling the
jackets, there was a clearance of 2–3 m between two adjacent
jackets, and then a segment in adjusted dimensions were
inserted into the clearance and welded to be an integrated
body. Cross-section of the joint structure between the
reclamation and pier sections is shown in Fig.5. Piled
foundations of the jackets were supported by the bearing
layer (deeper than A.P. –80 m), which shows N-values
continuously greater than 50.
Determination of final land reclamation height
Incremental consolidation pressure from the reclamation fill
was approximately 550 kN/m2 and 300 kN/m2 near the
offshore end and near the joint section, respectively, of the Drunway. The predicted total settlement in average was 7.2 m.
Contours of residual settlements calculated for in-service
period of 100 years are shown in Fig.4. The predicted
residual settlement along the D-runway was 0.50–0.65 m and
0.60–0.70 m near the joint section and end of the runway,
respectively. The seawall sections, where significant residual
settlement larger than 0.7 m was calculated, correspond to the
position of late backfilling, because these section was used as
either the open mouth (gateway) for ships/barges used for
reclamation filling or tentative material yard.
Joint Section
The joint structure between the reclamation and pier sections
is simply called as “joint section.” The joint section is a very
important structure, which takes the roles of both the seawall
of the manmade island and abutment for the joint girder. In
this project, well-foundation of steel pipe piles, which has a
good track record in bridge foundations and abutments, was
utilized (Fig.5). The well-foundation has consecutive 24
rectangle cells consisted of two parallel steel pipe sheet piles
as outer envelope and 25 orthogonal steel pipe sheet piles.
Summarizing the above results on the long-term settlement,
residual settlement for 100-year in-service period at the
highest point (the end) of the D-runway was expected to be
0.69 m (0.73 m after completion of filling). Consequently, in
consideration of the residual settlement, the filling of the Drunway at the start of in-service period was decided to be
0.70 m (slightly larger than 0.69 m) higher than the design
elevation, which is required from the aviation operation.
To ensure the stability of the well-foundation, which was
embedded to the bearing layer, it was required to utilize
lightweight backfill such as pneumatic mixing cement treated
soil (Kitazume and Satoh, 2003) and air-foam treated
lightweight soil (Tsuchida and Egashira ed., 2004; Watabe et
al., 2004). The lightweight backfill can contribute to decrease
the lateral earth pressure, consolidation settlement, and lateral
43
Yoichi Watabe & Takatoshi Noguchi
period. On the other hand, the latter section, i.e. manmade
island, is a so called high embankment. The elevation at the
offshore end of the D-runway is required to be higher than
A.P. +17.1 m, because airplanes have to overpass a large ship
navigating nearby.
Table 1. An example of mix proportion for the pneumatic
mixing cement treated soil.
W/C in weight
(%)
Cement per unit weight of slurry
C (kg/m3)
Dredged clay in front of the seawall
10.2
The soft subsoil under the mild slope rubble seawall, of
which allowable deformation is relatively large, and gravity
type caisson seawall, of which allowable deformation is
significantly small, was improved by SCP (low replacement
ratio) and CDM (block type), respectively. In addition,
lightweight treated soils were backfilled The upper soft
subsoil was improved by SD method to accelerate the
consolidation.
85
Dreaded clay from Tokyo Navigation Channel No. 1
8.5
103
Table 2. An example of mix proportion for the air-foam
treated lightweight soil.
Bulk density of clay
slurry
Ut (g/cm3)
Cement per unit
weight of slurry
C (kg/m3)
Volumetric
percentage of airfoam
in mixture (%)
The upper soft subsoil was improved by SD method to
accelerate the consolidation, however, it was expected that
the lower clayey layer, which cannot be improved because
of the large depths, would cause a long-term settlement of
approximately 0.70 m. Consequently, in consideration of
the residual settlement, the filling of the D-runway was
decided to be 0.70 m higher than the design elevation.
Target Ut = 1.02 g/cm3 (Jt = 10 kN/m3)
1.196
Target Ut = 1.12
1.211
78
g/cm3 (J
t
= 11
47
19.6
kN/m3)
11.8
In the construction of the D-runway, not only the ground
improvement technologies (SD, SCP, and CDM) but also the
new developed construction materials (pneumatic mixing
cement treated soil and air-foam treated lightweight soil)
were utilized. In addition, observational construction with
high-tech instruments for measurement was conducted.
Moreover, collaboration between geotechnical and geological
knowledge contributed to the interpretation of the ground
condition. In the-D-runway project, various technologies
accumulated through previous airport constructions were
applied to ground investigation, design, construction work, as
well as maintenance.
soil movement. In addition, the soft deposit in front of the
structure was improved by sand compaction piles with high
replacement ratio, to increase the lateral resistance of the well
foundation. Observational construction was conducted by
monitoring the settlement and lateral movement caused by
backfilling.
Effect of the Lightweight Soils
Cement treated lightweight soils made of dredged clay were
backfilled to the seawall. Major part of those was the
pneumatic mixing cement treated soil, which is appropriate to
large scale construction work, as a backfill of the mild slope
rubble seawall (Fig.3). In the joint section, to reduce the earth
pressure applying to the well-foundation whose height is
approximately 30 m from the seabed, pneumatic mixing
cement treated soil and air-foam treated lightweight soil were
placed at lower and upper sections, respectively (Fig.5).
ACKNOWLEDGMENTS
This paper was written in collaboration with Kanto Regional
Development Bureau of Ministry of Land, Infrastructure,
Transport and Tourism, Port and Airport Research Institute,
and Joint Venture for D-runway construction in the further
expansion project of Haneda Airport.
Total volume of lightweight soils (pneumatic mixing cement
treated soil and airfoam treated lightweight soil) used in the
reclamation work of the D-runway project was approximately
5,500,000 m3, which was equivalent to approximately 15% of
total reclamation soil volume of approximately 38,000,000
m3. A typical mix proportions of the pneumatic mixing
cement treated soil and air-foam treated lightweight soil used
in this project are shown in Tables 1 and 2, respectively.
REFERENCES
1. Katayama, T. (1991), Meeting the challenge to the very
soft ground –the Tokyo International Airport Offshore
Expansion Project. Proc. Int. Conf. Geotech. Engrg for
Coastal Development, GEO-COAST’91, 954–967.
2. Kitazume, M. and Satoh, T. (2003), Development of
pneumatic flow mixing method and its application to
Central Japan International Airport construction. Proc.
Ground Improvement, 7(3), 139–148.
3. Tsuchida, T. and Egashira, K. (ed.) (2004), The
lightweight treated soil method, A. A. Balkema
4. Watabe, Y., Itou, Y., Kang, M.-S. and Tsuchida, T.
(2004), One-dimensional compression of air-foam
treated lightweight geo-material in microscopic point of
view. Soils and Foundations, 44(6), 53–67.
SUMMARY
One of the remarkable features of the D-runway is the hybrid
structure consisted of piled pier and reclamation fill. The
former section was adopted in the river mouth of the Tama
River, to ensure a flow rate during times of flooding. This
piled pier section was constructed by assembling the jackets
prefabricated in a factory yard to shorten the construction
44