Ships – Floating platform
Patent
1998-04-09
1999-07-27
Avila, Stephen
Ships
Floating platform
114 65R, B63B 3544
Patent
active
059272279
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a hollow concrete-walled structure for marine use, and including application in ship-shaped and barge types of floating structure, floating effluent-treatment plant, semi-submersible floating structures, and marine gravity structures for use under water e.g. on the seabed.
Common to all these types of structures will be a hollow concrete-walled structure, and which gives buoyancy in the case of floating and semi-submersible vessels, and also defines storage space for cargo and houses the operating components of the vessel, accommodation for crew and related facilities.
However, the invention is not restricted to floating and semi-submersible vessels, and includes application to fully submerged concrete structures, which will be hollow in order to house operating components of the structure, and to receive and to process material for which the structure has been designed e.g. an off-shore seabed effluent treatment plant. Concrete structures are used in marine environments because of their superior resistance to deterioration in such conditions, when compared with metal structures, but generally are used only in static locations or as permanent fixtures. Examples of use in static locations include massive concrete structures to form oil production platforms, which are fabricated on or near to shore, towed out in a floating mode to the desired location, and then flooded so as to be lowered onto the seabed.
Therefore, while most concrete structures for marine use comprise fixed installations e.g. massive cast concrete quays, jetties etc, it is also known to use concrete in specially designed floating structures, such as oil productions platforms.
However, although internal metal reinforcement is usually provided in the concrete walls of known structures, essentially concrete of the structure is cast as a solid and very substantial mass.
There is a long standing appreciation that concrete is a desirable material to use in marine environments, but to date it has not been practical to use concrete in ship-shaped and similar structures, because of the massive weight of the lining walls and bulkheads of the vessel (when formed of reinforced concrete) and which adds very significantly to the structural weight of the vessel, but in addition this weight applies substantial bending loads to the vessel (in addition to buoyant loads) and which have to be withstood by additional reinforcement at locations of maximum anticipated bending and other stresses.
The invention therefore seeks to provide a hollow concrete-walled structure for marine use, and in which the density of the wall structure can be varied in a controlled and simple manner to suit design requirements while retaining the advantages of providing an outer water-contacting surface which is made of concrete.
The invention therefore provides a structural system which enhances the potential economic and technical advantages of concrete in off-shore structures, and to solve some of the problems associated with the use of conventional reinforced concrete construction techniques for such structures. Problems with such conventional designs include potentially high bending moments associated with large concrete ships and barges, as just referred to, and high differential heads associated with deep draft semi-submersibles for many applications and operating conditions, and also the potential for unseen corrosion of steel reinforcement within such structures, and also concerns with regard to long term fatigue problems.
The invention meets these objectives by incorporating void formers at selected locations in cast concrete walls of the hollow structure, and thereby provides both a novel method of fabrication, and novel structures obtained thereby.
The cast concrete walls of the structural system, incorporating void formers at selected locations, will preferably include metallic or non-metallic internal reinforcement e.g. so-called tensioning tendons, and preferably there is also built in structural self-monitoring.
By varying the amount, size a
REFERENCES:
patent: 1289781 (1918-12-01), Hubbell
patent: 2144939 (1939-01-01), Schiavi
patent: 3081600 (1963-03-01), Davidon
patent: 3537268 (1970-11-01), Georgii
patent: 4229497 (1980-10-01), Piazza
patent: 4263862 (1981-04-01), Shepherd
Derby Stanley
Jefferson Anthony
LandOfFree
Hollow concrete-walled structure for marine use does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hollow concrete-walled structure for marine use, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hollow concrete-walled structure for marine use will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-867147