Performance Criteria for Liquid Storage Tanks and Piping Systems Subjected to Seismic Loading

Abstract

In this paper, performance criteria for the seismic design of industrial liquid storage tanks and piping systems are proposed, aimed at introducing those industrial components into a performance-based design (PBD) framework. Considering “loss of containment” as the ultimate damage state, the proposed limit states are quantified in terms of local quantities obtained from a simple and efficient earthquake analysis. Liquid storage tanks and the corresponding principal failure modes (elephant's foot buckling, roof damage, base plate failure, anchorage failure, and nozzle damage) are examined first. Subsequently, limit states for piping systems are presented in terms of local strain at specific piping components (elbows, Tees, and nozzles) against ultimate strain capacity (tensile and compressive) and low-cycle fatigue. Modeling issues for liquid storage tanks and piping systems are also discussed, compared successfully with available experimental data, and simple and efficient analysis tools are proposed, toward reliable estimates of local strain demand. Using the above reliable numerical models, the proposed damage states are examined in two case studies: (a) a liquid storage tank and (b) a piping system, both located in areas of high seismicity.

Seismic intensity measures for above‐ground liquid storage tanks

“…As expected (Figures 7 and 11), Figure 13 reveals poor behaviour of the PGA (=IM s1 ) for both anchored and unanchored support conditions, with respect to IM v2 . For the unanchored system, IM v1 and IM v1 , Eq (7) reveal a response similar to the PGA (=IM s1 ), thus highlighting its dominant effect on the vector-valued IM. On the other hand, S a (T i ) (=IM s2 ), IM s5 , the AvgS a candidates (=IM s7 ), and the solution proposed through Equation 8 appear to be very close to the baseline solution of IM v2 .…”

“…Although they might relate to varying degrees of repair actions, these failure modes form a union of events that govern the violation of a specific system (global) damage state (DS). 5,6 In the course of seismic performance assessment, capturing the aforementioned failure modes requires employing appropriate engineering demand parameters (EDPs, eg stress and strain), 7 the pertinent thresholds, 7 a suitable structural model, 8 and multiple ground motion records, characterised by pertinent intensity measures (IMs) such as the peak ground acceleration (PGA) and the first-mode spectral acceleration S a (T 1 ). 9,10 The information provided above may be efficiently blended into the performance-based earthquake engineering concept, originally developed by Cornell and Krawinkler 1 for the Pacific Earthquake Engineering Research (PEER) Center, whereby the end-product is typically given in terms of the mean annual frequency (MAF) "λ" of exceeding, eg monetary loss or downtime thresholds.…”

Seismic risk assessment of liquid storage tanks via a nonlinear surrogate model

“…In this study, the aforementioned failure modes are appropriately combined to form 4 DSs of increasing severity, namely, no damage (DS0), minor (DS1), severe without leakage (DS2), and loss of containment (DS3), as originally proposed in. 37,38 It should be noted that the loss of containment is generally the main concern post-earthquake, as it constitutes a paramount source of industrial accidents with severe socioeconomic and environmental consequences. 23 Still, structural damage itself (with or without leakage) is also of concern because its aftermath is not confined to monetary losses only.…”

Seismic vulnerability analysis of storage tanks for oil and gas industry

“…The definition of proper EDPs and EDP-consistent damage states represents another delicate aspect of the fragility analysis; however, a limited number of contributions has been offered in the literature. For example, an interesting contribution by Vathi et al (2015) [13] provided the performance criteria for the design of storage tanks and piping systems, which identify the most critical failure modes for each structural category. The definition of damage states and the calculation of limit-state capacities are also presented in the current seismic design guidelines, e.g.…”