Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by and is under the jurisdiction of China Electricity Council.
Technical requirements of wind turbine foundation for offshore wind farm
1 Scope
This standard specified the environmental conditions, design and type selection, and technical requirements for operation and maintenance of wind turbine foundation for offshore wind farm.
This standard is applicable to newly constructed and renovated (extended) offshore wind farm
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 700 Carbon structural steels
GB/T 1591 High strength low alloy structural steels
GB/T 13476 Pretensioned spun concrete piles
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
mono-pile foundation
the foundation type based on a single pile
3.2
multi-pile cap foundation
the foundation type consisting of three or more piles and pile caps that undertake the superstructures
3.3
jacket foundation
the foundation type consisting of three or more piles and steel pipes or steel frames
Note: It is usually divided into multi-pile single column foundation, jacket foundation, portal foundation, etc.
3.4
gravity foundation
the foundation type to resist the load of the wind turbine depending on the dead weight and foundation resistance
3.5
bucket foundation
the foundation type of cylindrical structure with the top closed and the bottom open to resist the load of the wind turbine with the cylinder wall embedded in the foundation
3.6
floating foundation
the foundation type consisting of upper floating body structure and fendering system
4 Basic requirements
4.1 For offshore wind turbine foundation, the safety grade shall be Grade 1.
4.2 The foundation types of offshore wind turbine include mono-pile foundation, multi-pile cap foundation, jacket foundation, gravity foundation, bucket foundation and floating foundation, etc.
4.3 Before the foundation design of offshore wind turbine, marine hydrology, meteorological, engineering geology and topographic data shall be obtained.
4.4 The foundation type of offshore wind turbine shall be determined through technical and economic comparison according to the requirements of foundation conditions, marine environment, construction conditions, superstructure and operation and maintenance for the foundation.
4.5 The quality of foundation steel for offshore wind turbine shall meet the relevant requirements of GB/T 700 and GB/T 1591.
4.6 The main design loads of offshore wind turbine foundation shall include permanent load, variable load and accidental load, which shall meet the safety requirements of bearing capacity, deformability and stability.
4.7 For the foundation design of offshore wind turbine, the dynamic response of the wind turbine foundation and the superstructure system shall be verified.
4.8 The coupling static and dynamic analysis of the superstructure, infrastructure and foundation should be carried out for the offshore wind turbine foundation.
4.9 Fatigue shall be checked for the structure of offshore wind turbine foundation.
4.10 Anti-scour design shall be carried out for the offshore wind turbine foundation.
4.11 The lightning protection and grounding design shall be carried out for the offshore wind turbine foundation.
4.12 Cable outgoing line design shall be carried out for the offshore wind turbine foundation.
4.13 The anti-corrosion design shall be carried out for the offshore wind turbine foundation according to the durability under the marine environment conditions during the design service life cycle.
4.14 Anti-collision protection design shall be carried out for the offshore wind turbine foundation.
4.15 The docking system and other facilities shall be set for the offshore wind turbine foundation according to the later period operation and maintenance requirements.
4.16 Safety monitoring or inspection and maintenance shall be carried out for the offshore wind turbine foundation.
5 Environmental conditions
5.1 The environmental conditions of offshore wind turbines foundation mainly include: wind speed, sea tide, sea wave, sea current, sea ice, earthquake and seabed scouring.
5.2 The influence of annual average wind speed, turbulence intensity, wind shear and maximum wind speed occurs in 50 years at hub height shall be considered for the offshore wind turbine foundation design.
5.3 The design high water level, design low water level, extreme high water level, and extreme low water level shall be included in the offshore wind turbine foundation design.
5.4 The design wave height under the normal operating conditions and the maximum wave height under extreme operating conditions shall be considered for the offshore wind turbine foundation.
5.5 The design current velocity under normal operating conditions and the maximum current velocity under extreme operating conditions shall be considered for the offshore wind turbine foundation.
5.6 The design ice condition and extreme ice condition under normal operation shall be considered for the offshore wind turbine foundation according to the environmental conditions of the project location.
5.7 Earthquake impacts shall be considered for the offshore wind turbine foundation design.
5.8 The local scouring around the structure and the large-scale overall scouring of the wind farm shall be considered for the offshore wind turbine foundation design and operation.
Foreword III
1 Scope
2 Normative references
3 Terms and definitions
4 Basic requirements
5 Environmental conditions
6 Mono-pile foundation
7 Multi-pile cap foundation
8 Jacket foundation
9 Gravity foundation
10 Bucket foundation
11 Floating foundation
12 Technical requirements for foundation operation and maintenance