LOAD IMPACT ANALYSIS AND STABILITY ASSESSMENT OF PIPE RACKS IN PETROCHEMICAL PLANTS

This study presents a comprehensive load impact analysis and global stability assessment of a multi‑level steel pipe rack structure representative of petrochemical plant installations. The analysis confirms that pipe rack behaviour is governed by a complex interaction of gravity loads, piping‑induced forces, and seismic actions, rather than by conventional building load effects alone. Unlike typical building structures, operational pipe loads, thermal expansion, frictional forces at supports, and concentrated anchor forces play a decisive role in governing member forces and overall structural response. The results of response spectrum analysis establish that seismic loading governs global stability and lateral response of the pipe rack system. The structure satisfies ASCE 7‑16 minimum base shear requirements, with adequate modal mass participation exceeding 90% in both longitudinal and transverse directions. Maximum roof‑level displacements and inter‑storey drift ratios remain well within prescribed serviceability limits, confirming satisfactory lateral stiffness and stability performance under seismic excitation. Member‑level analysis highlights that beam elements are predominantly controlled by piping‑induced thermal and friction forces, while columns are governed by combined axial force and bending under seismic load combinations. Bracing members primarily resist axial forces and contribute significantly to controlling lateral deformation. Utilization ratios obtained from AISC 360‑16 design checks indicate that all structural members perform within acceptable limits, with maximum utilization ratios remaining below unity, thereby ensuring adequate strength and safety margins. The study clearly demonstrates the importance of realistic three‑dimensional modelling and integrated load consideration, particularly the inclusion of pipe–structure interaction effects, in accurately predicting force demand and deformation patterns in pipe rack structures. Neglecting thermal, friction, and anchor forces can lead to significant underestimation of design actions and potentially unsafe designs. Overall, the adopted methodology provides a practical and industry‑oriented framework for the safe, stable, and economical design of steel pipe racks in petrochemical plants. The findings of this study offer valuable guidance to practicing engineers by highlighting governing load mechanisms, critical response parameters, and the necessity of comprehensive load modelling, thereby contributing to improved reliability and performance of industrial pipe rack structures.

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