The composite bucket foundation (CBF) is a cost-competitive foundation for offshore wind turbines, which can be adapted to the loading characteristics and development needs of offshore wind farms due to its special structural form. There are seven sections divided inside the CBF by steel bulkheads, which are arranged in a honeycomb structure. The six peripheral sections with the skirt have the same proportions while the middle orthohexagonal one is a little larger. With the seven-section structure, the CBF has reasonable motion characteristics and towing reliability during the wet-tow construction process. Moreover, the pressure inside the compartments can control the levelness of the CBF during suction installation. Several large-scale model tests on suction installation of CBF have been performed in order to explore the feasibility of the tilt adjusting technique in saturated silty sand off the coast of Jiangsu in China. The composite bucket foundation in the tests has an outer diameter of 3.5 m and a clear wall height of 0.9 m. During the suction-assisted penetration process, the pressures in all the compartments were controlled to level the foundation in a timely operation. A convenient method is to improve the CBF inclination by controlling the inside differential pressure among the compartments. It can be commonly carried out by applying suction/positive pressure with intermittent pumping among the seven compartments. Another adjusting technique for a big tilt with deeper penetration is operated with decreasing the penetration depth achieved by suction-assisted lowering the relatively high compartments and positive pressures raising the relatively low compartments. Test results show that the reciprocating adjustment process can be repeated until the CBF is completely penetrated into a designed depth.

References

References
1.
Byrne
,
B. W.
, and
Houlsby
,
G. T.
,
2002
, “
Experimental Investigations of Response of Suction Caissons to Transient Vertical Loading
,”
J. Geotech. Geoenviron. Eng.
,
128
(
11
), pp.
926
939
.
2.
Liu
,
R.
,
Zhou
,
L.
,
Lian
,
J. J.
, and
Ding
,
H. Y.
,
2015
, “
Behavior of Monopile Foundations for Offshore Wind Farms in Sand
,”
J. Waterw. Port Coastal Ocean Eng.
,
142
(
1
), p.
04015010
.
3.
Zhu
,
B.
,
Byrne
,
B.
, and
Houlsby
,
G.
,
2013
, “
Long-Term Lateral Cyclic Response of Bucket foundation Foundations in Sand
,”
J. Geotech. Geoenviron. Eng.
,
139
(
1
), pp.
73
83
.
4.
Houlsby
,
G. T.
, and
Byrne
,
B. W.
,
2000
, “
Suction Caisson Foundations for Offshore Wind Turbines and Anemometer Masts
,”
J. Wind Eng.
,
24
(
4
), pp.
249
255
.
5.
Houlsby
,
G. T.
, and
Byrne
,
B. W.
,
2005
, “
Design Procedures for Installation of Suction Caisson in Clay and Other Materials
,”
Geotech. Eng.
,
158
(
2
), pp.
75
82
.
6.
Li
,
D.
,
Zhang
,
Y.
,
Feng
,
L.
, and
Gao
,
Y.
,
2015
, “
Capacity of Modified Suction Caissons in Marine Sand Under Static Horizontal Loading
,”
Ocean Eng.
,
102
, pp.
1
16
.
7.
Liu
,
R.
,
Chen
,
G. S.
,
Lian
,
J. J.
, and
Ding
,
H. Y.
,
2014
, “
Vertical Bearing Behaviour of the Composite Bucket Shallow Foundation of Offshore Wind Turbines
,”
J. Renewable Sustainable Energy
,
7
, p.
013123
.
8.
Zhu
,
B.
,
Kong
,
D. Q.
,
Chen
,
R. P.
,
Kong
,
L. G.
, and
Chen
,
Y. M.
,
2011
, “
Installation and Lateral Loading Tests of Suction Caissons in Silt
,”
Can. Geotech. J.
,
48
(
7
), pp.
1070
1084
.
9.
Lian
,
J. J.
,
Ding
,
H. Y.
,
Zhang
,
P. Y.
, and
Yu
,
R.
,
2012
, “
Design of Large-Scale Prestressing Bucket Foundation for Offshore Wind Turbines
,”
Trans. Tianjin Univ.
,
18
(
2
), pp.
79
184
.
10.
Lian
,
J. J.
,
Sun
,
L. Q.
,
Zhang
,
J. F.
, and
Wang
,
H. J.
,
2011
, “
Bearing Capacity and Technical Advantages of Composite Bucket Foundation of Offshore Wind Turbines
,”
Trans. Tianjin Univ.
,
17
(
2
), pp.
132
137
.
11.
Ding
,
H. Y.
,
Lian
,
J. J.
,
Li
,
A. D.
, and
Zhang
,
P. Y.
,
2013
, “
One-Step-Installation of Offshore Wind Turbine on Large-Scale Bucket-Top-Bearing Bucket Foundation
,”
Trans. Tianjin Univ.
,
19
(
3
), pp.
188
194
.
12.
Ding
,
H. Y.
,
Liu
,
Y. G.
,
Zhang
,
P. Y.
, and
Le
,
C. Y.
,
2015
, “
Model Tests on the Bearing Capacity of Wide-Shallow Composite Bucket Foundations for Offshore Wind Turbines in Clay
,”
Ocean Eng.
,
103
, pp.
114
122
.
13.
Zhang
,
P. Y.
,
Ding
,
H. Y.
, and
Le
,
C. H.
,
2013
, “
Hydrodynamic Motion of a Large Prestressed Concrete Bucket Foundation for Offshore Wind Turbines
,”
J. Renewable Sustainable Energy
,
5
(
6
), p.
063126
.
14.
Zhang
,
P. Y.
,
Ding
,
H. Y.
, and
Le
,
C. H.
,
2013
, “
Motion Analysis on Integrated Transportation Technique for Offshore Wind Turbines
,”
J. Renewable Sustainable Energy
,
5
(
5
), p.
053117
.
15.
Zhang
,
P. Y.
,
Ding
,
H. Y.
, and
Le
,
C. H.
,
2014
, “
Seismic Response of Large-Scale Prestressed Concrete Bucket Foundation for Offshore Wind Turbines
,”
J. Renewable Sustainable Energy
,
6
(
1
), p.
013127
.
16.
Zhang
,
J. F.
,
Zhang
,
X. N.
, and
Yu
,
C.
,
2016
, “
Wave-Induced Seabed Liquefaction Around Composite Bucket Foundations of Offshore Wind Turbines During the Sinking Process
,”
J. Renewable Sustainable Energy
,
8
(
2
), p.
023307
.
17.
Lian
,
J. J.
,
Chen
,
F.
, and
Wang
,
H. J.
,
2014
, “
Laboratory Tests on Soil–Skirt Interaction and Penetration Resistance of Suction Caissons During Installation in Sand
,”
Ocean Eng.
,
84
, pp.
1
13
.
18.
Zhang
,
P. Y.
,
Ding
,
H. Y.
, and
Le
,
C. H.
,
2013
, “
Installation and Removal Records of Field Trials for Two Mooring Dolphin Platforms With Three Suction Caissons
,”
J. Waterw. Port Coastal Ocean Eng.
,
139
(
6
), pp.
502
517
.
19.
Feld
,
T.
,
2001
, “
Suction Buckets, a New Innovative Foundation Concept, Applied to Offshore Wind Turbines
,” Ph.D. thesis, Aalborg University, Aalborg, Denmark.
20.
Kelly
,
R. B.
,
Houlsby
,
G. T.
, and
Byrne
,
B. W.
,
2006
, “
A Comparison of field and Laboratory Tests of Caisson Foundations in Sand and Clay
,”
Geotechnique
,
56
(
9
), pp.
617
626
.
21.
Ibsen
,
L. B.
,
Larsen
,
K. A.
, and
Barari
,
A.
,
2014
, “
Calibration of Failure Criteria for Bucket Foundations on Drained Sand Under General Loading
,”
J. Geotech. Geoenviron. Eng.
,
140
(
7
), p.
04014033
.
22.
Senders
,
M.
,
2008
, “
Suction Caissons in Sand as Tripod Foundations for Offshore Wind Turbines
,” Ph.D. thesis, The University of Western Australia, Crawley, Australia.
23.
Yu
,
H.
,
Zeng
,
X.
,
Neff
,
F. H.
,
Li
,
B.
, and
Lian
,
J.
,
2015
, “
Centrifuge Modeling of Offshore Wind Foundations Under Earthquake Loading
,”
Soil Dyn. Earthquake Eng.
,
77
, pp.
402
415
.
24.
Dekker
,
M. J.
,
2014
, “
The Modelling of Suction Caisson Foundations for Multi-Footed Structures
,” M.Sc. Thesis, Delft University of Technology, Delft, Netherlands.
25.
Dong Energy
,
2014
, “
Dong Debuts Bucket at Riffgrund
,” reNews Ltd., Winchester, UK, http://renews.biz/73160/dong-debuts-bucket-at-riffgrund/
26.
Dong Energy
,
2014
, “
Dong Energy Signs Another Suction Bucket Deal With SPT Offshore
,” OffshoreWind.biz, Rotterdam, The Netherlands, accessed Aug. 20, 2016, http://www.offshorewind.biz/2014/05/22/dong-energy-signs-another-suction-bucket-deal-with-spt-offshore/
27.
Golightly
,
C. R.
,
2014
, “
Monopile and Tripod/Jacket Foundations for Offshore Wind Foundations
,” Braemar Adjusting Forms, London, accessed Aug. 20, 2016, http://braemaradjusting.merchanttech.co.uk/files/Lecture-81_Monopile-and-Tripod_Jacket-Foundations-for-Offshore-Wind-Foundations-10th-April_Chris-Golightly-GO-ELS-Ltd.pdf
28.
Myounghak
,
O.
,
Osoon
,
K.
,
Keunsoo
,
K.
, and
Hyun
,
K.
,
2015
, “
Study on the Penetration Resistance of Suction Bucket Foundation
,”
EWEA OFFSHORE Conference
, Copenhagen, Denmark, March 10–12.
29.
Senders
,
M.
, and
Randolph
,
M. F.
,
2009
, “
CPT-Based Method for the Installation of Suction Caissons in Sand
,”
J. Geotech. Geoenviron. Eng.
,
135
(
1
), pp.
14
25
.
30.
Houlsby
,
G. T.
,
Kelly
,
R. B.
,
Huxtable
,
J.
, and
Byrne
,
B. W.
,
2005
, “
Field Trials of Bucket Foundations in Clay for Offshore Wind Turbine Foundations
,”
Geotechnique
,
55
(
4
), pp.
287
296
.
31.
Houlsby
,
G. T.
,
Kelly
,
R. B.
,
Huxtable
,
J.
, and
Byrne
,
B. W.
,
2006
, “
Field Trials of Bucket Foundations in Sand for Offshore Wind Turbine Foundations
,”
Geotechnique
,
56
(
1
), pp.
3
10
.
32.
Thieken
,
K.
,
Achmus
,
M.
, and
Schröder
,
C.
,
2014
, “
On the Behavior of Suction Buckets in Sand Under Tensile Loads
,”
Comput. Geotech.
,
60
, pp.
88
100
.
33.
Randolph
,
M. F.
, and
Gourvenec
,
S. M.
,
2010
,
Offshore Geotechnical Engineering
,
Taylor & Francis
,
London
.
34.
Cotter
,
O.
,
2010
, “
The Installation of Suction Caisson Foundations for Offshore Renewable Energy Structures
,” Ph.D. thesis, Oxford University, Oxford, UK.
35.
Foglia
,
A.
, and
Ibsen
,
L. B.
,
2014
, “
Bucket Foundations: A Literature Review
,” Department of Civil Engineering, Aalborg University, Denmark,
Technical Reports No. 176
.
36.
Madsen
,
S.
,
Andersen
,
L. V.
, and
Ibsen
,
L. B.
,
2013
, “
Numerical Buckling Analysis of Large Suction Caissons for Wind Turbines on Deep Water
,”
Eng. Struct.
,
57
, pp.
443
452
37.
Dendani
,
H.
, and
Colliat
,
J. L.
,
2002
, “
Girassol: Design Analysis and Installation of the Suction Anchors
,”
Offshore Technology Conference
, Houston, TX, OTC Paper No. 14209.
38.
Dendani
,
H.
,
2003
, “
Suction Anchors: Some Critical Aspects for Their Design and Installation in Clayey Soils
,”
Offshore Technology Conference
, Houston, TX, OTC Paper No. 15376.
39.
Peire
,
K.
,
Nonneman
,
H.
, and
Bosschem
,
E.
,
2009
, “
Gravity Base Foundations for the Thornton Bank offshore wind farm
,” International Association of Dredging Companies, The Hague, The Netherlands, https://www.iadc-dredging.com/ul/cms/terraetaqua/document/2/5/8/258/258/1/article-gravity-base-foundations-for-the-thornton-bank-offshore-wind-farm-terra115-3.pdf
40.
Ibsen
,
L. B.
,
Liingaard
,
M.
, and
Nielsen
,
S. A.
,
2005
, “
Bucket Foundation, A Status
,”
Conference Proceedings Copenhagen Offshore Wind
, Copenhagen, Denmark, Oct. 26–28.
41.
LeBlanc
,
C.
,
2009
, “
The Monopod Bucket Foundation—Recent Experience and Challenges Ahead
,” DNV GL, Oslo, Norway, last accessed Aug. 20, 2016, http://www.gl-group.com/pdf/No12_Bakmar.pdf
42.
Tran
,
M. N.
,
Randolph
,
M. F.
, and
Airey
,
D. W.
,
2007
, “
Installation of Bucket Foundations in Sand With Silt Layers
,”
J. Geotech. Geoenviron. Eng.
,
133
(
10
), pp.
1183
1191
.
43.
Det Norske Veritas (DNV)
,
1992
, “
Foundations
,” Classification Notes No. 30.4,” Det Norske Veritas, Hovik, Norway.
44.
Lehane
,
B. A.
,
Schneider
,
J. A.
, and
Xu
,
X.
,
2005
, “
The UWA-05 Method for Prediction of Axial Capacity of Driven Piles in Sand
,”
International Symposium on Frontiers in Offshore Geotechnics (IS—FOG 2005)
, Perth, Western Australia, Australia, Sept. 19–21, pp.
683
689
.
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