┌───────────────────────────┐ │ Structural Design Basis │ └─────────────┬─────────────┘ │ ┌───────────────────────┴───────────────────────┐ ▼ ▼ ┌───────────────────────────┐ ┌───────────────────────────┐ │ Working Stress Design │ │ Load & Resistance Factor │ │ (WSD / ASD) │ │ Design (LRFD) │ ├───────────────────────────┤ ├───────────────────────────┤ │ Applies a single safety │ │ Evaluates uncertainties │ │ factor to material yield │ │ using separate partial │ │ strength. │ │ safety factors. │ └───────────────────────────┘ └───────────────────────────┘
: Specialized deepwater or specialized ice-prone vertical structural schemes. Api Rp 2a-lrfd 2019 Pdf
: The official source for all American Petroleum Institute standards. : The official source for all American Petroleum
If you need the actual document legally, I’d suggest checking: Unlike the traditional Allowable Stress Design (WSD), LRFD
External forces (wind, wave, current, etc.) are multiplied by factors greater than 1.0 to account for statistical variability.
API RP 2A-LRFD (R2024) is a standard focused on the design of offshore structures using probabilistic, safety-factored approaches. Unlike the traditional Allowable Stress Design (WSD), LRFD provides a more consistent level of safety by applying separate factors to loads (factors > 1) and material resistance (factors < 1). Scope of the Standard
): Typically 1.35 to 1.6, because extreme storm waves and wind gusts carry a higher degree of unpredictability. Critical Sections Covered in the Standard