Detail of GB/T 42600-2023

Introduction of GB/T 42600-2023

GB/T 42600-2023 Wind energy generation systems - Tower and foundation design requirements of wind turbines 1 Scope This document specifies requirements and general principles to be used in assessing the structural integrity of onshore wind turbine support structures (including foundations). The scope includes the geotechnical assessment of the soil for generic or site specific purposes. The strength of any flange and connection system connected to the rotor nacelle assembly (including connection to the yaw bearing) are designed and documented according to this document or according to IEC 61400-1. The scope includes all lifecycle issues that may affect the structural integrity such as assembly and maintenance. The assessment assumes that load data has been derived as defined in IEC 61400-1 or IEC 61400-2 and using the implicit reliability level and partial safety factors for loads. 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. IEC 61400-1:2019 Wind energy generation systems - Part 1 : Design requirements Note: GB/T 18451.1-2022 Wind energy generation systems - Design requirements (IEC 61400-1:2019, IDT) IEC61400-2 Wind turbines - Part 2 : Small wind turbines Note: GB/T 17646-2017 Small wind turbines (IEC 61400-2:2013, IDT) ISO 2394:2015 General principles on reliability for structures ISO 6934 (all parts) Steel for the prestressing of concrete Note: GB/T 5223-2014 Steel wire for prestressing of concrete (ISO 6934-2 : 1991, NEQ) GB/T 5223.3-2017 Steel bars for the prestressing of concrete (ISO 6934-3:1991, NEQ) GB/T 5224-2014 Steel strand for prestressed concrete (ISO 6934-4:1991, NEQ) GB/T 20065-2016 Screw-thread steel bars for the prestressing of concrete (ISO 6934-5:1991, NEQ) ISO 6935 (all parts) Steel for the reinforcement of concrete Note: GB/T 1499.1-2017 Steel for the reinforcement of concrete - Part 1 : Hot rolled plain bars (ISO 6935-1 :2007, NEQ) GB/T 1499.2-2018 Steel for the reinforcement of concrete - Part 2 : Hot rolled ribbed bars (ISO 6935-2 :2015, NEQ) GB/T 1499.3-2010 Steel for the reinforcement of concrete - Part 3 : Welded fabric (ISO 6935-3: 1992, NEQ) ISO 9016:2012 Destructive tests on welds in merallice materials - Impact tests - Test specimen location, notch orientation and examination ISO 12944 (all parts) Paints and varnishes- Corrosion protection of steel structures by protective paint systems ISO 22965-1 Concrete - Part 1 : Methods of specifying and guidance for the specifier ISO 22965-2 Concrete - Part 2: Specification of constituent materials, production of concrete and compliance of concrete ISO 22966 Execution of concrete structures 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 61400-1, IEC 61400-2 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http : //www.electropedia.org/ ISO Online browsing platform: available at http : //www.iso.org/obp 3.1 assessment total set of activities performed in order to find out if the reliability of a structure is acceptable or not 3.2 characteristic load load accounting for required exceedance probability level and without partial safety factor for loads 3.3 characteristic buckling resistance load associated with buckling in the presence of inelastic material behaviour, the geometrical and structural imperfections that are inevitable in practical construction, and follower load effects 3.4 component class classification of the wind turbine structural components according to redundancy and safety requirements Note: Refer to IEC 61400-1, components are classified as Classes I and II. 3.5 component temperature local temperature which will affect the material properties of a component Note: The temperature shall be taken to be the ambient temperature unless protective or active means 3.6 design lifetime complete period of time for which the wind turbine will be designed to resist the specified loading including maintenance, idling, power production, starting and stopping 3.7 design load design force load (force) used in the action vs resistance equation for a limit state accounting for the required exceedance probability level and partial safety factor for loads 3.8 design resistance resistance used in the action vs resistance equation for a limit state accounting for the required exceedance probability level and partial safety factor for materials 3.9 design situations sets of physical conditions representing the real conditions occurring during a certain time interval for which the design will demonstrate that relevant limit states are not exceeded 3.10 dynamic stiffness for foundation tangent to the plot of linear or angular displacement of the foundation against force or moment applied to the foundation under zero or small strain (less than 10-4 soil shear strain) Note: Normally for concrete foundations, this is calculated for the effect of the soil mechanics alone assuming a rigid foundation. Where foundation flexibility is non-negligible, this should be taken into account in calculating dynamic stiffness 3.11 effect of actions effect of actions (or action effect) on structural members or on the whole structure Note: Internal force, moment, stress and strain are examples of action effect on structural members. Deflection and rotation are examples of action effect on the whole structure. 3.12 fatigue limit state structural failure due to damage accumulation under effects of repeated loading 3.13 geometrically and materially nonlinear analysis; GMNA analysis performed on the global structure based on shell bending theory applied to the perfect structure, using the assumption of nonlinear large deflection theory for the displacements, and adopting a nonlinear elasto-plastic material law ignoring the effect of strain hardening 3.14 geometrically and materially nonlinear analysis with imperfection included; GMNIA analysis performed on the global structure with imperfections explicitly included, based on shell bending theory applied to the imperfect structure, including nonlinear large deflection theory for the displacements, and adopting a nonlinear elasto-plastic material law ignoring the effect of strain hardening Note 1: A bifurcation eigenvalue check is included at each load level. Note 2: Examples of imperfect structure are unintended deviations from the ideal shape, imperfections in boundary conditions and residual stresses. 3.15 internal loads three orthogonal forces and three orthogonal moments that are reacted on an arbitrary plane cut through the structure Note: This relates to the usage of the term "loads" in IEC 61400-1, IEC 61400-2 and IEC 61400-3-1. This differs from the use in other areas of civil engineering. Often, the arbitrary plane is aligned with some physical interface or a local axis system. The singular internal load would be one of the three forces or three moments. See also 5.4.6. 3.16 materially nonlinear analysis; MNA analysis performed on the global structure based on shell bending theory applied to the perfect structure, using the assumption of small deflections, but adopting a nonlinear elasto-plastic material law ignoring the effect of strain hardening 3.17 nominal concrete cover layer of concrete between the concrete surface and the closest reinforcement surface including the specified tolerance for placing of reinforcement Note: The nominal concrete cover shall be calculated as the minimum concrete cover plus the specified tolerance. 3.18 nominal ratio ratio of values that are fixed on non-statistical bases, for instance on acquired experience or on physical conditions 3.19 nominal value value fixed on non-statistical bases, for instance on acquired experience or on physical conditions 3.20 partial safety factor for load factor for increasing a characteristic value of an effect of actions to calculate the design value of an effect of actions

Contents of GB/T 42600-2023