A Probabilistic Approach for the Assessment of LOC Events in Steel Storage Tanks Under Seismic Loading

Abstract

The damage states in a storage tank subjected to seismic loading can induce loss of containment (LOC) with possible consequences (fire, explosion, etc..) both for the surrounding units and people. This aspect is particularly crucial for the Quantitative Risk Analysis (QRA) of industrial plants subjected to earthquakes. Classical QRA methodologies are based on standard LOC conditions whose frequency of occurrence is mainly related to technological accident rather than natural events and are thus useless. Therefore, it is evident the necessity of establishing new procedures for the evaluation of the frequencies of occurrence of LOC events in storage tanks when subjected to an earthquake. Consequently, in this work a simple procedure founded on a probabilistic linear regression-based model is proposed, which uses simplified numerical models typically adopted for the seismic response of above ground storage tanks. Based on a set of predetermined LOC events (e.g. damage in the pipes, damage in the nozzles, etc..), whose probabilistic relationship with the local response (stress level, etc..) derives from experimental tests, the probabilistic relationship of selected response parameters with the seismic intensity measure (IM) is established. As result, for each LOC event, the cloud analysis method is used to derive the related fragility curve.

A Screening Methodology for the Identification of Critical Units in Major-Hazard Facilities Under Seismic Loading

“…Fragility Analysis of industrial equipment and relevant LOC conditions is crucial for a credible risk and consequence-based analysis of process plants. A large number of methodologies for deriving fragility curves, especially for the most diffused equipment like storage tanks, can be found in the literature (Salzano et al, 2003;HAZUS, 2001;Campedel et al, 2008;Buratti and Tavano, 2014;Bakalis et al, 2015;Iervolino et al, 2004;Paolacci et al, 2015;Kaynia, 2013;Paolacci et al, 2018). Nevertheless, few contributions focused on the possible LOC events and potential consequences (Kalemi et al, 2016;Campedel et al, 2008).…”

“…The few contributions present in literature are typically based on empirical approaches (Fabbrocino et al, 2005), in which the relationship between LOC and seismic damage is defined on accident databases and is generally considered as deterministic. A probabilistic approach for the assessment of LOC event in steel storage tanks under seismic loading has been proposed in (Paolacci et al, 2018). Since further developments in this regard are necessary, only deterministic DS/LOC correlation matrices are herein considered, leaving more refined approaches to future investigations.…”

Computing resilience of process plants under Na-Tech events: Methodology and application to sesmic loading scenarios

“…where Ф is the standard Gaussian cumulative distribution, μ and β are respectively the mean value and logarithmic standard deviation of the capacity distribution. Fragility curves are available in the literature for a wide range of natural hazards, limit states and equipment types [87,88], otherwise they must be computed resorting to statistical analysis of damage data in historical Na-Tech events or by numerical modeling [89][90][91][92].…”

Seismic fragility analysis of LNG sub-plant accounting for component dynamic interaction

“…In literature, most of the work is done by selecting handsome amount of natural accelerograms and performing simplified analysis e.g. linear regression analysis to compute the parameters for fragility functions (Bursi et al 2017;Caprinozzi et al 2017;Paolacci et al 2018). Moreover, for rational quantification of the seismic performance of civil facilities, Performance-Based Earthquake Engineering (PBEE) methodology is used by Cornell and Krawinkler (2000).…”