Skip to main content
European Commission logo print header
Inhalt archiviert am 2022-12-27

CONCRETE PLATFORMS FOR DEEP WATER

Ziel

To investigate the technical and economic potential for the use of concrete hulls for floating platforms in water depths typically 400 m extending to 1000 meters.
The project demonstrated that the relatively large mass of concrete hull is no disadvantage in cost and payload capacity, given appropriate design and sufficient draught. Thick walls lead to a simple structure enabling external pressure to be resisted without the need for stiffeners.
A fatigue assessment of critical areas at the pontoon node intersection showed that cumulative fatigue damage was an order of magnitude less than the normally accepted maximum permissible damage for an offshore concrete structure.
A survey of potential UK construction sites showed that a choice exists of several sites suitable for constructing TLP hulls. Two stage construction would be required, the first stage being built in a dry dock followed after float-out by completion of hull construction afloat on inshore moorings.
The main technical considerations in designing concrete hulls for tension leg platforms were examined and the feasibility of construction in the UK was investigated and confirmed. An outline design and cost estimate were developed for a concrete TLP suitable for a 27000 tonne payload is a water depth of 400 metres located West of Shetland.
The hull configurations examined had four columns and four pontoons, both circular and rectangular section pontoons being considered. Design requirements for the hull included practical considerations of construction, deck mating and installation, floating stability, structural strength and installation, floating stability, structural strength and serviceability. For the tethers upper and lower tension limits suitable as preliminary design criteria were derived. These are critical to be feasibility of the combined hull tether system and relationships between the main variables were established.
Analyses of wave-induced tether tension were performed on a range of trial configurations for which hull dimensions, mean density and draught were varied. Other sources of tension variation, calculated or estimated were added to the results to give maximum and minimum tension estimates. From a parametric study of the data, optimisation procedures were developed enabling configuration s complying with the design criteria to be readily identified. The data were updated by incorporating improved estimates of hull density enabling a particular configuration to be selected for structural analysis.
A survey was made of the basic requirements for a concrete Catenary Moored Floater (CMF). For the two primary hull types, viz. gravity stabilised and column stabilised, relationships were established between hull dimensions and draught. These enabled configurations ssatisfying particular stability criterial to be identified. An interim assessment was made and the scope for further work outlined.

Aufforderung zur Vorschlagseinreichung

Data not available

Koordinator

MAC ALPINE OFFSHORE LTD
EU-Beitrag
Keine Daten
Adresse
ST ALBANS ROAD HEMEL HEMPSTEAD
HEMEL HEMPSTEAD
Vereinigtes Königreich

Auf der Karte ansehen

Gesamtkosten
Keine Daten