Seismic reliability of electric power networks: methodology and application

Vanzi, Ivo

doi:10.1016/s0167-4730(96)00024-0

Cited by 67 publications

(50 citation statements)

References 1 publication

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“…An FF, in its simplest form, quantifies the stochastic uncertainty related to the damage event of interest (eg, [42]). Values of such an FF may be viewed as results of propagating stochastic uncertainty.…”

Section: 2mentioning

confidence: 99%

Explosive damage to industrial buildings: Assessment by resampling limited experimental data on blast loading

Vaidogas

2005

Journal of Civil Engineering and Management

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Abstract. Assessment of damage to industrial buildings due to accidental explosions in air is considered. It is suggested to formulate the result of the damage assessment in the form of risk. The expression of risk embraces probabilities of foreseeable damage events (damage probabilities) and outcomes (consequences) of suffering these events. The situation is examined when blast loading imposed by an accidental explosion is predicted by a series of experiments. They yield a small-size sample of blast loading characteristics. It is suggested to idealise the formation of explosive damage to industrial buildings by means of event trees diagrams. A quantitative analysis of these diagrams can be carried out by developing fragility functions for their branching points. Each branching point is used to represent a structural failure contributing to the final explosive damage. The fragility functions are applied to expressing the conditional probabilities of explosive damage. With these probabilities, a technique of frequentist (Fisherian) inference is applied to assessing the explosive damage. This technique is called statistical resampling (Efrons bootstrap) and applied as a practical, albeit not equivalent alternative to the Bayesian approaches. It is shown that statistical resampling is capable to yield confidence intervals of damage probabilities and can be applied almost automatically. It operates without using cumbersome methods of statistical inference developed in the classical statistics. The bootstrap confidence intervals do not contain any subjective information except the degree of confidence for which these intervals are computed. The degree of confidence must be chosen by the engineer. The bootstrap confidence intervals are applied to estimating damage probabilities on the basis of the small-size sample of blast loading characteristics. An estimate of the risk of explosive damage is expressed as a set of bootstrap confidence intervals computed for damage probabilities and related outcomes of this damage.

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Section: 2mentioning

confidence: 99%

Explosive damage to industrial buildings: Assessment by resampling limited experimental data on blast loading

Vaidogas

2005

Journal of Civil Engineering and Management

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“…Since the fragilities of the macro components are expressed as a function of the soil acceleration, conversion from MM intensity to acceleration in cm/s is needed; the empirical law [21] a(cm/s)"10' > (10) has been used. The (deterministic) attenuation value in Equation (10), has again been considered to be the mean value of a lognormal random variable with coe$cient of variation .…”

Section: Model Of the Seismic Actionmentioning

confidence: 99%

Structural upgrading strategy for electric power networks under seismic action

Vanzi¹

2000

Earthquake Engng. Struct. Dyn.

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SUMMARYThis paper presents a procedure to identify an optimal retro"tting strategy for electric power networks (EPN) subjected to seismic events. The optimization consists of the minimization, under economic constraints, of the probability of power cut-o! at the nodes where electric energy is most needed in the post-earthquake situation; these nodes are referred to as critical nodes. The EPN model used herein has been presented earlier and is brie#y reviewed in the text. The method to individuate the critical nodes, based upon the value of an index proposed in this study, is presented "rst; then the optimization procedure to select which elements of the EPN to upgrade is examined based upon a standard reliability study. Its e!ectiveness is tested against routinely used upgrading schemes for an existing EPN (the one of Sicily in Italy). It is shown that the optimization procedure is e!ective and leads to a signi"cant saving of economic resources.

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“…Fujisaki et al 2014). Vanzi (1996) and Hwang and Huo (1998) only consider the fragility of substations. The SYNER-G project (Cavalieri et al 2014b) proposes a methodology for assessing the overall performance of an electrical power system, but in doing so makes the assumption that conduits are not vulnerable to direct physical damage and so damage potential is limited to substations and generation plants.…”

Section: Introductionmentioning

confidence: 99%

Seismic performance of buried electrical cables: evidence-based repair rates and fragility functions

Kongar

Giovinazzi

Rossetto

2016

Bull Earthquake Eng

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The fragility of buried electrical cables is often neglected in earthquakes but significant damage to cables was observed during the 2010-2011 Canterbury earthquake sequence in New Zealand. This study estimates Poisson repair rates, similar to those in existence for pipelines, using damage data retrieved from part of the electric power distribution network in the city of Christchurch. The functions have been developed separately for four seismic hazard zones: no liquefaction, all liquefaction effects, liquefactioninduced settlement only, and liquefaction-induced lateral spread. In each zone six different intensity measures (IMs) are tested, including peak ground velocity as a measure of ground shaking and five metrics of permanent ground deformation: vertical differential, horizontal, maximum, vector mean and geometric mean. The analysis confirms that the vulnerability of buried cables is influenced more by liquefaction than by ground shaking, and that lateral spread causes more damage than settlement alone. In areas where lateral spreading is observed, the geometric mean permanent ground deformation is identified as the best performing IM across all zones when considering both variance explained and uncertainty. In areas where only settlement is observed, there is only a moderate correlation between repair rate and vertical differential permanent ground deformation but the estimated model error is relatively small and so the model may be acceptable. In general, repair rates in the zone where no liquefaction occurred are very low and it is possible that repairs present in this area result from misclassification of hazard observations, either in the raw data or due -016-0077-3 to the approximations of the geospatial analysis. Along with hazard intensity, insulation material is identified as a critical factor influencing cable fragility, with paper-insulated lead covered armoured cables experiencing considerably higher repair rates than crosslinked polyethylene cables. The analysis shows no trend between cable age and repair rates and the differences in repair rates between conducting materials is shown not to be significant. In addition to repair rate functions, an example of a fragility curve suite for cables is presented, which may be more useful for analysis of network connectivity where cable functionality is of more interest than the number of repairs. These functions are one of the first to be produced for the prediction of damage to buried cables.123 Bull Earthquake Eng (2017) 15:3151-3181 DOI 10.1007/s10518

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Seismic reliability of electric power networks: methodology and application

Cited by 67 publications

References 1 publication

Explosive damage to industrial buildings: Assessment by resampling limited experimental data on blast loading

Explosive damage to industrial buildings: Assessment by resampling limited experimental data on blast loading

Structural upgrading strategy for electric power networks under seismic action

Seismic performance of buried electrical cables: evidence-based repair rates and fragility functions

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