Abstract: The technological platforms and pipe racks are structures in oil and gas refineries, Petrochemical, chemical and power plants are primarily steel structures which occupy large space for critical operations and effective routing of large diameter pipes. Technological platforms and process pipe racks are the main arteries of process plant as they are designed to support pipes, power cables and instrument cable trays. The seismic evaluation of these pipe rack supporting structures in refineries is one of the most important part of structural analysis for safe and stable production. Pipe racks are mostly long, narrow structures that carry pipes in longitudinal as well as transverse direction. These pipe racks are prone to large displacements during major earthquake ground motions. These earthquake loads acting laterally causes large displacement and thus sway criteria become critical. This sway can lead to large deformation of structure and may collapse easily. To avoid these problems, we consider Second Order Effect i.e., P – Delta effect in designing. As the height of structure increases, P- Delta effect becomes important. The P-Delta analysis can be done for both static and dynamic analysis. In this study, static analysis is carried out on pipe rack structure and results based on storey displacement, moments and storey drift are observed. It is observed that 9% displacement of column is increased when second order analysis is carried out. The use of Second Order analysis results in more realistic behaviour of the structure. In this dissertation it is observed that for wind loads and mid-scale earthquakes, bracing members get failed after performing second order analysis. Since this study is done for short run, the displacement variation is observed by 9%. Due to these variations in displacement and moment, bracings have failed. If this analysis carried out on long run, then variations will increase definitely and it may cause failure in structure.

Keywords: Second Order Analysis, P-Delta effect, Direct analysis method, Oil and Gas, Pipe Rack, Seismic analysis, Static analysis, etc.

| DOI: 10.17148/IARJSET.2022.9168