Document replaced. This document has been replaced by a standard (ST) in the DNV GL portfolio: DNVGL-ST-C All DNV GL service documents may be. Download DNV GL’s standard for Offshore concrete structures. Find the most up-to-date version of DNV-OS-C at Engineering
|Published (Last):||2 July 2012|
|PDF File Size:||4.29 Mb|
|ePub File Size:||1.42 Mb|
|Price:||Free* [*Free Regsitration Required]|
This paper aims to show a refurbishment project of an off-shore wind turbine, combining its natural purpose of exploiting the wind resources in the windiest sea areas along the coasts of Italy Sardinia, Sicily, Abruzzo, Apulia together with the possibility of using its structure as a tourist accommodation. Later, in order to study the effects on vertical cables fixed to the sea bottom, a detailed analysis of the floating anchorage TLP Tension Leg Platform was carried out.
When it comes to designing offshore concrete structures, important effects that need to be considered are, for example, the concrete fatigue performance under water, effects of water pressure in pores and cracks and principles for watertightness. Laboratory tests conducted by the material producer at an independent laboratory and witnessed by DNV GL are used to determine the fresh and hardened grout properties.
In the early days of the industry when concrete platforms and installations started to be used, DNV GL experts verified such structures in Norway.
This is believed to be due to the concrete degradation caused by cyclic varying pore water pressure and the pumping effect of water ingressing and exiting opening and closing cracks.
Updated concrete standard Historically, operators used the former Norwegian concrete standards for offshore structures.
Unlike steel structures, concrete structures are built locally and therefore also promote the local economy. Please sign in or become a member for free. Home Downstream Special reports 27 October Creating a complete code for offshore concrete structures. To address the current offshore concrete developments, DNV GL is dv reviewing the Offshore Concrete Standard to provide updates and new guidance, particularly for harsh locations.
In addition, an audit of the manufacturing facility is undertaken with a focus on the quality control procedures in place for the product. However, the Eurocodes focus on onshore structures and this has to some extent resulted in important offshore experience being excluded. On this basis, a floating wind turbine called ARYA, has been designed as case-study.
Creating a complete code for offshore concrete structures
One of these materials is high-strength grout. A review of the offshore grouting procedure and quality control documentation is undertaken and forms the basis for the full-scale mock-up test performed to replicate the intended offshore application.
The purpose of the Eurocodes is to provide a harmonised set of design and construction rules that are applicable throughout Europe. TLP consists of a nearly fully submerged cylindrical platform, which supports a 5 MW wind turbine and is linked to the sea bottom by 3 ties which assure stability and limited tilting, even under the worst loads induced by wind and sea.
First of all, the 2 tourist-receptive structures Hotel and bar-restaurant around the wind tower have been designed and checked.
OFFSHORE STANDARD DNV-OS-C, Offshore concrete structures, DET NORSKE VERITAS.
This changed in when Eurocodes were adopted throughout Europe, including in Norway. DNV GL believes that this type of certification scheme will facilitate the adoption of these materials by operators. Ultimately, the review of DNV OS C aims to create a unified consistent standard, covering the full lifecycle of an offshore concrete structure, that can be adopted by the industry.
Concrete advantages In the polar extremes, concrete structures are durable and robust to resist collisions with icebergs and are resistant to abrasion from floating ice. In particular, submerged concrete does not perform as well as above-water concrete under fatigue loading.
This content is available to members only. No other standard currently available to the industry covers the whole lifecycle of a concrete offshore structure and provides detailed design guidance. Historically, operators used the former Norwegian concrete standards for offshore structures.
DNV MPQA Certification for PAGEL Offshore Grout Material
Another interesting and unique feature of the updated DNV-OS-C is the systematics it provides for the qualification of new and innovative materials dmv for offshore use. The analysis was based on the extreme environmental conditions of the site where it has been suggested to install the system.