Fragility of Mechanical, Electrical, and Plumbing Equipment

2010 ◽  
Vol 26 (2) ◽  
pp. 451-472 ◽  
Author(s):  
Keith Porter ◽  
Gayle Johnson ◽  
Robert Sheppard ◽  
Robert Bachman

A study for the Multidisciplinary Center for Earthquake Engineering Research (MCEER) provides fragility functions for 52 varieties of mechanical, electrical, and plumbing (MEP) equipment commonly found in commercial and industrial buildings. For the majority of equipment categories, the MCEER study provides multiple fragility functions, reflecting important effects of bracing, anchorage, interaction, etc. The fragility functions express the probability that the component would be rendered inoperative as a function of floor acceleration. That work did not include the evidence underlying the fragility functions. As part of the ATC-58 effort to bring second-generation performance-based earthquake engineering to professional practice, we have compiled the original MCEER specimen-level performance data into a publicly accessible database and validate many of the original fragility functions. In some cases, new fragility functions derived by ATC-58 methods show somewhat closer agreement with the raw data. Average-condition fragility functions are developed here; we will address in subsequent work the effect of potentially important—arguably crucial—performance-modifying factors such as poor anchorage and interaction.

2007 ◽  
Vol 23 (2) ◽  
pp. 471-489 ◽  
Author(s):  
Keith Porter ◽  
Robert Kennedy ◽  
Robert Bachman

The Applied Technology Council is adapting PEER's performance-based earthquake engineering methodology to professional practice. The methodology's damage-analysis stage uses fragility functions to calculate the probability of damage to facility components given the force, deformation, or other engineering demand parameter (EDP) to which each is subjected. This paper introduces a set of procedures for creating fragility functions from various kinds of data: (A) actual EDP at which each specimen failed; (B) bounding EDP, in which some specimens failed and one knows the EDP to which each specimen was subjected; (C) capable EDP, where specimen EDPs are known but no specimens failed; (D) derived, where fragility functions are produced analytically; (E) expert opinion; and (U) updating, in which one improves an existing fragility function using new observations. Methods C, E, and U are all introduced here for the first time. A companion document offers additional procedures and more examples.


2019 ◽  
Vol 36 (1) ◽  
pp. 271-298 ◽  
Author(s):  
Nicola Giordano ◽  
Khalid M. Mosalam ◽  
Selim Günay

Existing unreinforced masonry (URM) buildings represent a significant part of the constructed facilities. Unfortunately, in case of seismic actions, their structural behavior is negatively affected by the low capacity of masonry components to withstand lateral forces. For this reason, in the past decades, URM buildings have been responsible for fatalities and large economic losses even in the case of moderate earthquakes. This article presents the seismic loss assessment of an old masonry building damaged during the 2014 South Napa earthquake using the framework of the Pacific Earthquake Engineering Research Center’s Performance-Based Earthquake Engineering. For this purpose, the performance is expressed in terms of expected monetary loss curves for different hazard scenarios. Structural and non-structural losses are considered in the analysis using a practical, yet accurate, structural idealization of the URM building, which is validated by the observed damage from the 2014 South Napa earthquake.


2010 ◽  
Vol 26 (4) ◽  
pp. 951-965 ◽  
Author(s):  
Mary C. Comerio ◽  
Howard E. Blecher

The performance-based earthquake engineering (PBEE) methodology developed by the Pacific Earthquake Engineering Research (PEER) center uses data from recent earthquakes to calibrate its loss models. This paper describes a detailed review of building department permit data from the 1989 Loma Prieta earthquake and the 1994 Northridge earthquake. Although the data is limited to wood-framed residential structures, it provides some insight into the length of time between an event and re-occupancy. Based on a review of approximately 4,900 records, the typical repair of damaged multifamily residential buildings required two years and building replacement required almost four years. When this data is supplemented with additional case studies from other events, the capacity to better calibrate downtime models will improve, particularly if construction-repair times are separated from estimates of the time gap between closure and start-of-repair.


2018 ◽  
Vol 2 (6) ◽  
pp. 400 ◽  
Author(s):  
Davide Forcellini

Decision making approaches to manage bridge recovering after the impact of multiple hazards are increasing all over the world. In particular, bridges can be considered critical links in highway networks because of their vulnerability and their resilience can be assessed on the basis of evaluation of direct and indirect losses. This paper aims at proposing a new methodology to assess indirect losses for bridges subjected to multiple hazards. The method applied to calculate direct costs is the credited Performance Based Earthquake Engineering (PBEE) methodology by the Pacific Earthquake Engineering Research (PEER) center. Therefore, the main objective of the study consists in the assessment of indirect losses that are generally neglected elsewhere. In particular, the paper proposes to calculate indirect losses from direct costs and to divide them into connectivity losses and prolongation of time. The presented formulation has been applied to a real case study aimed at strengthening a benchmark bridge with several isolated configurations. The results show that the application of the proposed methodology allows to evaluate possible solutions to strengthen the original configuration.


2010 ◽  
Vol 26 (1) ◽  
pp. 41-62 ◽  
Author(s):  
Brendon A. Bradley

This paper is concerned with the inclusion of epistemic uncertainties in component fragility functions used in performance-based earthquake engineering. Conventionally fragility functions, defining the probability of incurring at least a specified level of damage for a given level of seismic demand, are defined by a mean and standard deviation and assumed to have a lognormal distribution. However, there exist many uncertainties in the development of such fragility functions. The sources of epistemic uncertainty in fragility functions, their consideration, combination, and propagation are presented and discussed. Two empirical fragility functions presented in literature are used to illustrate the epistemic uncertainty in the fragility function parameters due to the finite size of the datasets. These examples and the associated discussions illustrate that the magnitude of epistemic uncertainties are significant and there are clear benefits of the consideration of epistemic uncertainties pertaining to the documentation, quality assurance, implementation, and updating of fragility functions. Epistemic uncertainties should therefore always be addressed in future fragility functions developed for use in seismic performance assessment.


2016 ◽  
Vol 32 (1) ◽  
pp. 441-461 ◽  
Author(s):  
Abbas Javaherian Yazdi ◽  
Terje Haukaas ◽  
Tony Yang ◽  
Paolo Gardoni

This paper employs a logistic regression technique to develop multivariate damage models. The models are intended for performance assessments that require the probability that structural components are in one of several damage states. As such, the developments represent an extension of the univariate fragility functions that are omnipresent in contemporary performance-based earthquake engineering. The multivariate logistic regression models that are put forward here eliminate several of the limitations of univariate fragility functions. Furthermore, the new models are readily substituted for existing fragility functions without any modifications to the existing performance-based analysis methodologies. To demonstrate the proposed modeling approach, a large number of tests of reinforced concrete shear walls are employed to develop multivariate damage models. It is observed that the drift ratio and aspect ratio of concrete shear walls are among the parameters that are most influential on the damage probabilities.


2019 ◽  
Vol 18 (4) ◽  
pp. 1693-1721 ◽  
Author(s):  
Leonardo Rossi ◽  
Marco Stupazzini ◽  
Davide Parisi ◽  
Britta Holtschoppen ◽  
Gabriella Ruggieri ◽  
...  

AbstractThe 2012 Emilia-Romagna earthquake, that mainly struck the homonymous Italian region provoking 28 casualties and damage to thousands of structures and infrastructures, is an exceptional source of information to question, investigate, and challenge the validity of seismic fragility functions and loss curves from an empirical standpoint. Among the most recent seismic events taking place in Europe, that of Emilia-Romagna is quite likely one of the best documented, not only in terms of experienced damages, but also for what concerns occurred losses and necessary reconstruction costs. In fact, in order to manage the compensations in a fair way both to citizens and business owners, soon after the seismic sequence, the regional administrative authority started (1) collecting damage and consequence-related data, (2) evaluating information sources and (3) taking care of the cross-checking of various reports. A specific database—so-called Sistema Informativo Gestione Europa (SFINGE)—was devoted to damaged business activities. As a result, 7 years after the seismic events, scientists can rely on a one-of-a-kind, vast and consistent database, containing information about (among other things): (1) buildings’ location and dimensions, (2) occurred structural damages, (3) experienced direct economic losses and (4) related reconstruction costs. The present work is focused on a specific data subset of SFINGE, whose elements are Long-Span-Beam buildings (mostly precast) deployed for business activities in industry, trade or agriculture. With the available set of data, empirical fragility functions, cost and loss ratio curves are elaborated, that may be included within existing Performance Based Earthquake Engineering assessment toolkits.


2019 ◽  
Vol 35 (3) ◽  
pp. 1511-1514
Author(s):  
Panagiotis Galanis ◽  
Marco Broccardo ◽  
Lukas Bodenmann ◽  
Božidar Stojadinović

Discussers (Michel et al.) address the paper “A Framework to Evaluate the Benefit of Seismic Upgrading” written by the coauthors of this response. Discussers present the compliance factor approach to evaluate existing structures and determine the need for a seismic upgrade implemented in the Swiss code SIA 269/8 and compare this approach to the one presented in the discussed paper. The approach proposed in the discussed paper combines elements of the Pacific Earthquake Engineering Research (PEER) Center Performance-Based Earthquake Engineering (PBEE) framework and the standard actuarial frequency-severity approach. Discussers criticize this approach as not being risk based and, consequently, consider it inappropriate for seismic evaluation of existing buildings. Coauthors welcome the comparison of different approaches for evaluation of existing buildings but disagree with the discussers’ characterization of the PEER PBEE framework and, by extension, the approach of the discussed paper.


2007 ◽  
Vol 23 (2) ◽  
pp. 459-469 ◽  
Author(s):  
Keith Porter

New performance-based earthquake engineering methods developed by the Pacific Earthquake Engineering Research Center, the Applied Technology Council, and others include damage analysis at a highly detailed level, requiring the compilation of fragility functions for a large number of damageable generic structural and nonstructural components. This brief paper presents the development of a fragility function for hydraulic elevators. It uses post-earthquake survey data from 91 elevators in nine California locations after two earthquakes. Surveys were used to collect data on facilities and elevators. Ground-motion records from the California Integrated Seismic Network were used to estimate engineering demands at each site. Binary regression analysis was used to fit a fragility function, which takes the form of a lognormal cumulative distribution function with median value of PGA=0.42 g and logarithmic standard deviation of 0.3. The fragility function appears to be reasonable based on four criteria.


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