%0 Journal Article
%T Some Remarks on the Seismic Demand Estimation in the Context of Vulnerability Assessment of Large Steel Storage Tank Facilities
%A Antonio Di Carluccio
%A Giovanni Fabbrocino
%J ISRN Civil Engineering
%D 2012
%R 10.5402/2012/271414
%X The seismic behavior of steel tanks is relevant in industrial risk assessment because collapse of these structures may trigger other catastrophic phenomena due to loss of containment. Therefore, seismic assessment should be focused on for leakage-based limit states. From a seismic structural perspective, damages suffered by tanks are generally related to large axial compressive stresses, which can induce shell buckling near the base and large displacements of unanchored structures resulting in the detachment of piping. This paper approaches the analysis of seismic response of sliding, nonuplifting, unanchored tanks subject to seismic actions. Simplified methods for dynamic analysis and seismic demand estimation in terms of base displacement and compressive shell stress are analyzed. In particular, attention is focussed on some computational issues related to the solution of the dynamic problem and on the extension of the incremental dynamic analysis (IDA) technique to storage tanks. 1. Introduction Earthquakes represent an external hazard for industrial installations and may trigger accidents, that is, fire and explosions resulting in injury to people and to near field equipments or constructions, whenever structural failures result in the release of hazardous material. In recent years the quantitative risk analysis (QRA) procedures have been extended to include seismic analysis for industrial installation, for example, petrochemical plants, and chemical plants, storage facility [1¨C3]. From the structural perspective, steel tanks for oil storage are standardized structures both in terms of design and construction [4¨C6]. A review of the international standards points out that the design procedures evolved slowly. Nevertheless, a large number of postearthquake damage observations [7] are available and empirical vulnerability functions have been developed [8]. This is a privileged case with respect to other civil engineering structures that basically can be seen as single prototypes; however, empirical fragility typically suffers some shortcomings. In fact, site effects can influence vulnerability data, so that a disaggregation is hard to perform. Therefore, the development of analytical models able to predict the response of the structural components and systems under seismic loading is worth exploring. The present work is aimed at discussing a numerical procedure able to analyze the response of anchored and unanchored tanks under two-dimensional ground motion accounting for the structure sliding. The main objective of the study is, in particular, the
%U http://www.hindawi.com/journals/isrn.civil.engineering/2012/271414/