ANSI API RP 2TOP-2019 pdf download.Topsides Structure
1 Scope
This document provides requirements for the design, fabrication, transportation, installation, modification, and structural integrity management for the topsides structure for an oil and gas platform; API 2TOP complements API 2A-WSD, API 2A-LRFD, ISO 19903, API 2FPS, API 2T, ISO 19905-1, and API 2N, which give requirements for various forms of substructures. It is based on ISO 19901-3:2010 (Corrected version, 15-Dec-2011) and is consistent with ISO 19901-3:2014 to the fullest extent possible and modified only where needed for API purposes. Requirements in this standard concerning modifications and maintenance relate only to those aspects that are of direct relevance to the structural integrity of the topsides structure. The actions on the topsides structure and structural components are derived from this document and where necessary, in combination with API, other international standards and the ISO 19900 series. The resistances of structural components of the topsides structure are determined by the use of international or national building codes, as specified in this document. If the topsides structure is integrated with the supporting substructure to help resist global platform forces, the requirements of this standard are supplemented with applicable requirements of the associated substructure such as API 2A-LRFD for fixed steel structures and API 2FPS for floating structures.
If the user chooses to design a fixed platform structure based on ASD/WSD, then they shall follow the latest edition of API 2A-WSD for designing both the topsides and the substructure. With respect to floating facilities, API 2FPS states that structural design of floating platforms shall be based on either the partial factor design format or the WSD format unless directed otherwise by the classification society. It is noted that the partial factors presented in API 2FPS have been derived from a calibration process focused mainly on North Sea environmental conditions, as explained in that document. Therefore, use of these partial factors for the Gulf of Mexico or for sites other than the North Sea can yield an uncalibrated design. Consequently, in the absence of partial factors specifically derived for the intended environment, floating structures in US waters should be designed utilizing the WSD format following the provisions given in API 2FPS regarding the use of this format, as agreed by the owner and the local regulatory authority.
5.2.2 Use of National Codes and Standards
The detailed design for a topsides structure shall be based on national or regional building codes. These should normally be those for the nation or region in which the platform is to be located, but may, with the agreement of the owner and the regulator, be those from other nations or regions. The standards used for fabrication should be consistent with and compatible with those used for design. In the case of this document, the reference national building code or specification is AISC 360-10. NOTE As stated in Clause 1, this document does not apply to those parts of floating offshore structures and mobile offshore units that are governed by the rules of a recognized classification society and that are wholly within the class rules. In order to realize a consistent level of reliability, the partial action factors shall be taken from the relevant standard governing the substructure on which the topsides is mounted and shall be used unmodified. The partial resistance factors shall be taken from the reference national building code, AISC 360-10, and modified by the application of a building code correspondence factor (see 8.1). Floating structures and production jack-ups that are registered as vessels are also subject to the requirements of the prospective flag state or classification society acting on behalf of the flag state.ANSI API RP 2TOP-2019 pdf download
