Wind shielding in refining and petrochemical facilities

Arguably the most influential climatic load affecting the structural design of gulf coast refining and petrochemical facilities is wind. Despite this fact, little has been done to customize wind design for these unique facilities. This paper proposes a probabilistic model to predict the magnitude of shielding that is provided by the vast network of pipe rack structures that encircle these densely arranged facilities. The probabilistic model is built from data obtained through a broad sampling of pipe rack configurations simulated with hurricane force winds using computational fluid dynamics (CFD). The CFD simulation approach is validated against published wind tunnel data that relate the proposed methodology to code recognized procedures (i.e. wind load reductions corroborated by wind tunnel testing). A reliability analysis is then carried out to re-calibrate the LRFD design equation to include the proposed shielding effects while maintaining the code specified level of reliability.