scholarly journals Creating Fragility Functions for Performance-Based Earthquake Engineering

2007 ◽  
Vol 23 (2) ◽  
pp. 471-489 ◽  
Author(s):  
Keith Porter ◽  
Robert Kennedy ◽  
Robert Bachman
Keyword(s):  
Expert Opinion ◽  
Professional Practice ◽  
Earthquake Engineering ◽  
Damage Analysis ◽  
Fragility Functions ◽  
Fragility Function ◽  
Applied Technology ◽  
Engineering Demand Parameter ◽  
Performance Based Earthquake Engineering ◽  
First Time

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.

Fragility of Mechanical, Electrical, and Plumbing Equipment

2010 ◽  
Vol 26 (2) ◽  
pp. 451-472 ◽  
Author(s):  
Keith Porter ◽  
Gayle Johnson ◽  
Robert Sheppard ◽  
Robert Bachman
Keyword(s):  
Professional Practice ◽  
Earthquake Engineering ◽  
Fragility Functions ◽  
Subsequent Work ◽  
Engineering Research ◽  
Modifying Factors ◽  
Industrial Buildings ◽  
Average Condition ◽  
Performance Based Earthquake Engineering ◽  
Level Performance

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.

Epistemic Uncertainties in Component Fragility Functions

2010 ◽  
Vol 26 (1) ◽  
pp. 41-62 ◽  
Author(s):  
Brendon A. Bradley
Keyword(s):  
Quality Assurance ◽  
Earthquake Engineering ◽  
Epistemic Uncertainty ◽  
Finite Size ◽  
Seismic Demand ◽  
Fragility Functions ◽  
Seismic Performance Assessment ◽  
Fragility Function ◽  
Documentation Quality ◽  
Performance Based Earthquake Engineering

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.

scholarly journals Fragility of Hydraulic Elevators for Use in Performance-Based Earthquake Engineering

2007 ◽  
Vol 23 (2) ◽  
pp. 459-469 ◽  
Author(s):  
Keith Porter
Keyword(s):  
Earthquake Engineering ◽  
Cumulative Distribution ◽  
Nonstructural Components ◽  
Engineering Research ◽  
Fragility Function ◽  
The Pacific ◽  
Applied Technology ◽  
Binary Regression Analysis ◽  
Ground Motion Records ◽  
Performance Based Earthquake Engineering

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.

Analysis of Seismic Fragility Functions of Highway Embankments

2020 ◽  
Author(s):  
Balázs Hübner ◽  
András Mahler
Keyword(s):  
Finite Element ◽  
Earthquake Engineering ◽  
Seismic Fragility ◽  
Response Analysis ◽  
Fragility Functions ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Fragility Function ◽  
Damage States ◽  
Log Normal

Vulnerability assessment of structures is a vitally important topic among earthquake engineering researchers. Generally, their primary focus is on the seismic performance of buildings. Less attention is paid to geotechnical structures, even though information about the performance of these structures (e.g. road embankments, levees, cuts) during an earthquake is essential for planning remediation and rescue efforts after disasters. In this paper the seismic fragility functions of a highway embankment are defined following an analytical methodolgy. The technique is a displacement-based evaluation of seismic vulnerability. Displacements of an embankment during a seismic event are approximated by a 2-D nonlinear ground response analysis using the finite element method. The numerical model was calibrated based on the results of a 1-D nonlinear ground response analysis. The expected displacements were calculated for 3 different embankment heights and Peak Ground Acceleration (PGA) values between 0,05 and 0,35g. Based on the results of the 2-D finite element analysis, the relationship between displacements and different seismic intensity measures (PGA, Arias-intensity) was investigated. Different damage states were considered, and the probability of their exceedance was investigated. The seismic fragility functions of the embankments were developed based on probability of exceedance of these different damage states based on a log-normal fragility function. The legitimacy of using a log-normal fragility function is also examined.

Multivariate Fragility Models for Earthquake Engineering

2016 ◽  
Vol 32 (1) ◽  
pp. 441-461 ◽  
Author(s):  
Abbas Javaherian Yazdi ◽  
Terje Haukaas ◽  
Tony Yang ◽  
Paolo Gardoni
Keyword(s):  
Logistic Regression ◽  
Earthquake Engineering ◽  
Shear Walls ◽  
Performance Assessments ◽  
Fragility Functions ◽  
Structural Components ◽  
Logistic Regression Models ◽  
Damage Models ◽  
Damage States ◽  
Performance Based Earthquake Engineering

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.

scholarly journals Empirical fragility functions and loss curves for Italian business facilities based on the 2012 Emilia-Romagna earthquake official database

2019 ◽  
Vol 18 (4) ◽  
pp. 1693-1721 ◽  
Author(s):  
Leonardo Rossi ◽  
Marco Stupazzini ◽  
Davide Parisi ◽  
Britta Holtschoppen ◽  
Gabriella Ruggieri ◽  
...  
Keyword(s):  
Earthquake Engineering ◽  
Economic Losses ◽  
Seismic Events ◽  
Fragility Functions ◽  
Administrative Authority ◽  
Specific Data ◽  
Related Data ◽  
Long Span ◽  
Performance Based Earthquake Engineering ◽  
Source Of Information

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.

scholarly journals An approach to quantify the influence of ground motion uncertainty on elastoplastic system acceleration in incremental dynamic analysis

2017 ◽  
Vol 20 (11) ◽  
pp. 1744-1756 ◽  
Author(s):  
Peng Deng ◽  
Shiling Pei ◽  
John W. van de Lindt ◽  
Hongyan Liu ◽  
Chao Zhang
Keyword(s):  
Dynamic Analysis ◽  
Ground Motion ◽  
Earthquake Engineering ◽  
Structural Response ◽  
Incremental Dynamic Analysis ◽  
Degree Of Freedom ◽  
Maximum Acceleration ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Performance Based Earthquake Engineering

Inclusion of ground motion–induced uncertainty in structural response evaluation is an essential component for performance-based earthquake engineering. In current practice, ground motion uncertainty is often represented in performance-based earthquake engineering analysis empirically through the use of one or more ground motion suites. How to quantitatively characterize ground motion–induced structural response uncertainty propagation at different seismic hazard levels has not been thoroughly studied to date. In this study, a procedure to quantify the influence of ground motion uncertainty on elastoplastic single-degree-of-freedom acceleration responses in an incremental dynamic analysis is proposed. By modeling the shape of the incremental dynamic analysis curves, the formula to calculate uncertainty in maximum acceleration responses of linear systems and elastoplastic single-degree-of-freedom systems is constructed. This closed-form calculation provided a quantitative way to establish statistical equivalency for different ground motion suites with regard to acceleration response in these simple systems. This equivalence was validated through a numerical experiment, in which an equivalent ground motion suite for an existing ground motion suite was constructed and shown to yield statistically similar acceleration responses to that of the existing ground motion suite at all intensity levels.

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