Analysis of Vulnerability Curves and Surfaces of Storage Tanks Considering Vector Seismic Motion Parameters

Abstract

Storage tanks are essential apparatus utilized for the containment, regulation, and secure management of liquid substances, serving a vital function in industrial production, chemical processes, and energy storage. In the assessment of seismic performance for storage tanks, using fragility to examine associated failure probability is a prevalent approach. Nevertheless, deriving the fragility curve of a storage tank from a singular seismic motion component adds ambiguity in evaluating the seismic performance of the tank. Moreover, while assessing the seismic fragility of large-capacity storage facilities, engineers frequently encounter intricate technical circumstances, a substantial quantity of finite element model units, and extended computation durations. Therefore, this work uses endurance time analysis (ETA) to efficiently assess the seismic performance of storage tanks and validates the efficacy of this method using incremental dynamic analysis using 22 selected near-field seismic waves. Utilizing the idea of ETA, the parameters of endurance time and seismic motion are transformed to derive the dynamic response of the secondary seismic motion parameter. Subsequently, scalar vulnerability curve analysis proceeds for the two seismic motion parameters independently, followed by vector vulnerability surface analysis incorporating the two parameters. The findings suggest that ETA can approximately ascertain the ultimate seismic resistance of the storage tank via a singular dynamic analysis, highlighting its validity and efficacy in the dynamic response evaluation of storage structures. In contrast to scalar vulnerability curves, vector vulnerability surfaces may enhance the dependability of probabilities and significantly reduce the uncertainty of the hazardous curve in structural response analysis.