Title:
Design and Construction Overview of Offshore Concrete Gravity-Based-Structures: Past, Present, and Future
Author(s):
Widianto; Jameel Khalifa; Erik Åldstedt; Kåre O. Hæreid; Kjell Tore Fosså
Publication:
Symposium Paper
Volume:
337
Issue:
Appears on pages(s):
1-20
Keywords:
Floating Construction, Reinforced Concrete Design, D-regions, Structural Analysis, Offshore Structures, Strut-and-tie, Wave loads
DOI:
10.14359/51724544
Date:
1/23/2020
Abstract:
An offshore concrete Gravity-Based-Structure (GBS) is a massive concrete structure placed on the seafloor and held in place strictly by its own weight, without need for anchors. This paper focuses on concrete GBSs used as the base of integrated oil drilling and production platforms. The summary of key distinct structural features of several major GBSs, since the first Ekofisk GBS (installed in the North Sea, offshore Norway, in 1973) until the latest Hebron GBS (installed in the Grand Banks, Canada, in 2017), is presented. This paper also discusses several unique loads that GBSs have to resist. An overview of structural analysis and design methodology is described in detail. Key considerations for preliminary sizing of GBS structural components are presented. Typical construction phases, methods, and the importance of constructability are explained. Finally, potential future research topics that would result in a more cost-effective offshore concrete GBS are discussed.
Related References:
ACI 347. 2014. Guide to Formwork for Concrete. American Concrete Institute, Farmington Hills, Michigan.
Det Norske Veritas. 1974. Rules for the design, construction and inspection of fixed offshore structures. Oslo, Norway.
DNVGL-ST-C502. 2018. Offshore Concrete Structures.
ISO 19903-2006. 2006. Petroleum and Natural Gas Industries - Fixed Concrete Offshore Structures. International Organization for Standardization.
Lie R., Aasheim E. E. and Engen M. 2018. Thermal Cracking of a Concrete Arch Dam. FE analyses with a 3D non-linear material model for concrete. Proceedings of the 14th ICOLD International Benchmark Workshop on Numerical Analysis of Dams, Stockholm.
Norwegian Standard, NS 3473.E:2003, “Concrete structures – Design and Detailing Rules,” Standard Norge, Norway, 2003, 128 pp.
Oberlies, R., Khalifa, J., Huang, J., Hetland, S., Younan, A., Overstake, M., and Slocum, S. 2014. Determination of Wave Impact Loads for the Hebron Gravity Based Structure (GBS). Presented at the 33th International Conference on Offshore Mechanics & Arctic Engineering, San Francisco, California, USA, 8-13 June. OMAE2014-23503.
Widianto, Chichester, J., Younan, A., Khalifa, J., Komperla, K., and Bidne, K. 2018. Hebron Platform: Innovative Design and Efficient Execution. Proc. Offshore Technology Conference, Houston, Texas, 30 April – 4 May, OTC-28803-MS.
Widianto, Khalifa, J., Younan, A., Karlsson, T., Stuckey, P., and Gjorven, A. 2013. Design of Hebron Gravity Based Structure for Iceberg Impact. Proceedings of the Twenty-third (2013) International Offshore and Polar Engineering, Anchorage, Alaska, USA, 30 June – 5 July. ISOPE-I-13-036.
Widianto, Khalifa, J., Taborda, G., and Bidne, K. 2016. Concrete Gravity-Based Structure: Construction of the Hebron Offshore Oil Platform. Concrete International, American Concrete Institute, 38(6):29-36.
Widianto, Khalifa, J., Hæreid,K.O., Fosså, K.T., and Gjørven A. 2020. Hebron Offshore Concrete Gravity-Based-Structure: Novel Design and Construction Techniques. ACI Special Publication, ACI.
Fosså, K.T. and Widianto. 2020. Concrete Mix Design Development for Offshore Structures. ACI Special Publication, ACI.