scholarly journals Nonlinear Dynamic Analysis of Masonry Buildings and Definition of Seismic Damage States

2016 ◽  
Vol 10 (1) ◽  
pp. 192-209 ◽  
Author(s):  
A.J. Kappos ◽  
V.K. Papanikolaou
Keyword(s):  
Fragility Curves ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Critical Issue ◽  
Seismic Damage ◽  
Masonry Building ◽  
Nonlinear Behaviour ◽  
Building Stock ◽  
Damage States ◽  
Diaphragm Action

A large part of the building stock in seismic-prone areas worldwide are masonry structures that have been designed without seismic design considerations. Proper seismic assessment of such structures is quite a challenge, particularly so if their response well into the inelastic range, up to local or global failure, has to be predicted, as typically required in fragility analysis. A critical issue in this respect is the absence of rigid diaphragm action (due to the presence of relatively flexible floors), which renders particularly cumbersome the application of popular and convenient nonlinear analysis methods like the static pushover analysis. These issues are addressed in this paper that focusses on a masonry building representative of Southern European practice, which is analysed in both its pristine condition and after applying retrofitting schemes typical of those implemented in pre-earthquake strengthening programmes. Nonlinear behaviour is evaluated using dynamic response-history analysis, which is found to be more effective and even easier to apply in this type of building wherein critical modes are of a local nature, due to the absence of diaphragm action. Fragility curves are then derived for both the initial and the strengthened building, exploring alternative definitions of seismic damage states, including some proposals originating from recent international research programmes.

Implications of cumulated seismic damage on the seismic performance of unreinforced masonry buildings

2014 ◽  
Vol 47 (2) ◽  
pp. 157-170 ◽  
Author(s):  
Amaryllis Mouyiannou ◽  
Andrea Penna ◽  
Maria Rota ◽  
Francesco Graziotti ◽  
Guido Magenes
Keyword(s):  
Nonlinear Dynamic ◽  
Fragility Curves ◽  
Seismic Damage ◽  
Unreinforced Masonry ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Capacity ◽  
Building Stock ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses

The seismic capacity of a structure is a function of the characteristics of the system as well as of its state, which is mainly affected by previous damage and deterioration. The cumulative damage from repeated shocks (for example during a seismic sequence or due to multiple events affecting an unrepaired building stock) affects the vulnerability of masonry buildings for subsequent events. This paper proposes an analytical methodology for the derivation of state-dependent fragility curves, taking into account cumulated seismic damage, whilst neglecting possible ageing effects. The methodology is based on nonlinear dynamic analyses of an equivalent single degree of freedom system, properly calibrated to reproduce the static and dynamic behaviour of the structure. An application of the proposed methodology to an unreinforced masonry case study building is also presented. The effect of cumulated damage on the seismic response of this prototype masonry building is further studied by means of nonlinear dynamic analyses with the accelerograms recorded during a real earthquake sequence that occurred in Canterbury (New Zealand) between 2010 and 2012.

scholarly journals Fragility curves for Italian URM buildings based on a hybrid method

2021 ◽  
Author(s):  
A. Sandoli ◽  
G. P. Lignola ◽  
B. Calderoni ◽  
A. Prota
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Ultimate Limit State ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Behaviour ◽  
Building Stock ◽  
Ground Acceleration ◽  
Damage Scenario

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

scholarly journals Mechanics-based fragility curves for Italian residential URM buildings

2020 ◽  
Author(s):  
Marco Donà ◽  
Pietro Carpanese ◽  
Veronica Follador ◽  
Luca Sbrogiò ◽  
Francesca da Porto
Keyword(s):  
Reference Model ◽  
Fragility Curves ◽  
National Level ◽  
Building Stock ◽  
Damage Scenarios ◽  
Complex Evaluation ◽  
Proposed Model ◽  
2009 L’Aquila Earthquake ◽  
Damage States ◽  
Observed Damage

Abstract Seismic risk assessment at the territorial level is now widely recognised as essential for countries with intense seismic activity, such as Italy. Academia is called to give its contribution in order to synergically deepen the knowledge about the various components of this risk, starting from the complex evaluation of vulnerability of the built heritage. In line with this, a mechanics-based seismic fragility model for Italian residential masonry buildings was developed and presented in this paper. This model is based on the classification of the building stock in macro-typologies, defined by age of construction and number of storeys, which being information available at national level, allow simulating damage scenarios and carrying out risk analyses on a territorial scale. The model is developed on the fragility of over 500 buildings, sampled according to national representativeness criteria and analysed through the Vulnus_4.0 software. The calculated fragility functions were extended on the basis of a reference model available in the literature, which provides generic fragilities for the EMS98 vulnerability classes, thus obtaining a fragility model defined on the five EMS98 damage states. Lastly, to assess the reliability of the proposed model, this was used to simulate damage scenarios due to the 2009 L’Aquila earthquake. Overall, the comparison between model results and observed damage showed a good fit, proving the model effectiveness.

scholarly journals Fragility Curves for Italian Urm Buildings Based on a Hybrid Method

2021 ◽  
Author(s):  
Antonio Sandoli ◽  
Gian Piero Lignola ◽  
Bruno Calderoni ◽  
Andrea Prota
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Ultimate Limit State ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Behaviour ◽  
Building Stock ◽  
Ground Acceleration ◽  
Damage Scenario

Abstract A hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions.Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure (IM) to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minim value of PGAs defined for each buildings class.To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber (MCS) macroseismic intensity scale has been used and the corresponding fragility curves developed.Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

scholarly journals Sensitivity of the Fragility Curve on Type of Analysis Methods, Applied Ground Motions and Their Selection Techniques

2021 ◽  
Author(s):  
Samreen Fatimah ◽  
Jenna Wong
Keyword(s):  
Dynamic Analysis ◽  
Fragility Curves ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Fragility Curve ◽  
Frame Structure ◽  
Steel Moment Frame ◽  
New Approach ◽  
Multiple Parameters ◽  
The Impact

AbstractFragility curves are the primary way of assessing seismic risk for a building with numerous studies focused on deriving these fragility curves and how to account for the inherent uncertainty in the seismic assessment. This study focuses on a three-story steel moment frame structure and performs a fragility assessment of the building using a new approach called SPO2FRAG (Static Pushover to Fragility) that is based on pushover analysis. This new approach is further compared and contrasted against traditional nonlinear dynamic analysis approaches like Incremental Dynamic Analysis and Multiple Stripe Analysis. The sensitivity of the resulting fragility curves is studied against multiple parameters including uncertainties in ground motion, the type of analysis method used and the choice of curve fitting technique. All these factors influence the fragility curve behavior and this study assesses the impact of changing these parameters.

scholarly journals Development of Seismic Fragility Functions for a Moment Resisting Reinforced Concrete Framed Structure

2016 ◽  
Vol 10 (1) ◽  
pp. 42-51 ◽  
Author(s):  
D. P. McCrum ◽  
G. Amato ◽  
R. Suhail
Keyword(s):  
Reinforced Concrete ◽  
Mechanical Model ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Pushover Analysis ◽  
Frame Structure ◽  
Building Structures ◽  
Reinforced Concrete Structure ◽  
Moment Resisting ◽  
Damage States

Understanding the seismic vulnerability of building structures is important for seismic engineers, building owners, risk insurers and governments. Seismic vulnerability defines a buildings predisposition to be damaged as a result of an earthquake of a given severity. There are two components to seismic risk; the seismic hazard and the exposure of the structural inventory to any given earthquake event. This paper demonstrates the development of fragility curves at different damage states using a detailed mechanical model of a moment resisting reinforced concrete structure typical of Southern Europe. The mechanical model consists of a complex three-dimensional finite element model of the reinforced concrete moment resisting frame structure and is used to define the damage states through pushover analysis. Fragility curves are also defined using the HAZUS macro-seismic methodology and the Risk-UE macro-seismic methodology. Comparison of the mechanically modelled and HAZUS fragility curve shows good agreement while the Risk-UE methodology shows reasonably poor agreement.

scholarly journals Characteristics And Results Of The Near Real-Time System For Estimating The Seismic Damage In Romania

2015 ◽  
Vol 11 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Toma-Danila Dragos ◽  
Cioflan Carmen Ortanza ◽  
Balan Stefan Florin ◽  
Manea Elena Florinela
Keyword(s):  
Real Time ◽  
Fragility Curves ◽  
Construction Material ◽  
Seismic Damage ◽  
Loss Estimation ◽  
Building Stock ◽  
Time System ◽  
Attenuation Relations ◽  
Real Time System ◽  
Earthquake Parameters

Abstract The Near Real-Time System for Estimating the Seismic Damage in Romania, implemented in 2012 at the National Institute for Earth Physics, is one of the automated systems that can directly contribute to saving many lives right after a major earthquake, by translating earthquake parameters into damage probabilities for different areas within Romanian counties and showing emergency intervention necessities, and can also lead to mitigation actions before an earthquake, through raising awareness and highlighting vulnerable aspects of the building stock and economic and social impacts. This paper aims to present the scientific background of this constantly upgrading system, and to show different results for relevant scenarios, for intermediate-depth Vrancea earthquakes and other crustal earthquakes. Several important questions are tried to be answered, like: “How credible are the estimated losses?”, “What are the most vulnerable aspects?” or “How can the damage maps be useful for authorities?”. Currently, the system uses for building loss estimation the analytical methods (as the Improved-Displacement Capacity Method - I-DCM) implemented within the open-source software SELENA (SEismic Loss EstimatioN using a logic tree Approach), together with HAZUS methods for estimating the human casualties. The building stock is defined through 48 different capacity and fragility curves, depending on construction material, height and age. As hazard data, PGA and SA values obtained through the ShakeMap System and based on real recordings and attenuation relations are used. The area currently analyzed by the system consists of 19 Romanian Counties, capital Bucharest and 9 regions in northern Bulgaria; resolution of the data is at administrative unit (commune or city) level. We aim to provide an insight of each part of this system, justify the choices made and also discuss the improvement possibilities.

Seismic Vulnerability of Reinforced Concrete Building Based on the Development of Fragility Curve: A Case Study

2016 ◽  
Vol 845 ◽  
pp. 252-258 ◽  
Author(s):  
Erlin Wijayanti ◽  
Stefanus Kristiawan ◽  
Edy Purwanto ◽  
Senot Sangadji
Keyword(s):  
Standard Deviation ◽  
Ground Motion ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Pushover Analysis ◽  
Fragility Curve ◽  
Capacity Curves ◽  
Capacity Spectrum ◽  
Damage States ◽  
Spectrum Curve

This study aims to determine the seismic vulnerability of 5th Building of Engineering Faculty, Sebelas Maret University by developing its fragility curves. Fragility curve is a measure of probabilistic seismic performance under various ground motion. The intensity of ground motion adopted in this study is median spectral displacement, , with lognormal standard deviation, βds as uncertainty parameter. The value of lognormal standard deviation is adopted from HAZUS. The parameters of median spectral displacements are identified from the capacity spectrum curve. The capacity curve obtained from non-linear static pushover analysis. Capacity curves can be converted into capacity spectrum to identify the location of the median spectral displacement at various damage states. The obtained fragility curves provide information on the probability of various damage states to occur when certain ground motion level strikes the building under study.

EFFECT OF SKEW ANGLE ON SEISMIC VULNERABILITY OF RC BOX-GIRDER HIGHWAY BRIDGES

2013 ◽  
Vol 13 (06) ◽  
pp. 1350013 ◽  
Author(s):  
AHMED ABDEL-MOHTI ◽  
GOKHAN PEKCAN
Keyword(s):  
Ground Motion ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Nonlinear Dynamic Analysis ◽  
Highway Bridges ◽  
Skew Angle ◽  
Box Girder ◽  
Skewed Bridges ◽  
Damage States ◽  
Skew Angles

In this study, the seismic vulnerability of post-tensioned reinforced concrete box-girder highway bridges with moderate-to-large skew angles to various levels of ground motion intensity is investigated. The fragility curves are generated by performing incremental nonlinear dynamic analysis (IDA) on the bridges of skew angles of 0, 30, and 60°s. A total of 45 ground motion pairs are considered to develop the fragility curves. The damage states are presented and quantified based on the column rotational ductility and superstructure displacements at the abutments. Furthermore, the fragility curves constructed are compared against those recommended by HAZUS. It is demonstrated that as the skew angle increases, skew bridges become more vulnerable to seismically induced damages. It is also shown that the HAZUS fragility curves may not lead to a consistent prediction of the vulnerability of skewed bridges.

Seismic Damage Detection Using Pushover Analysis

2011 ◽  
Vol 255-260 ◽  
pp. 2496-2499 ◽  
Author(s):  
Mohammadreza Vafaei ◽  
Azlan bin Adnan ◽  
Mohammadreza Yadollahi
Keyword(s):  
Damage Detection ◽  
Detection Method ◽  
Ground Motions ◽  
Pushover Analysis ◽  
Damage Index ◽  
Seismic Damage ◽  
Nonlinear Behaviour ◽  
Method Base ◽  
Concrete Building ◽  
Story Drift

Inter-story drift ratio is a general damage index which is being used to detect damaged stories after severe ground motions. Since this general damage index cannot detect damaged elements also the severity of imposed damages on elements, a new real-time seismic damage detection method base on artificial neural networks was proposed to overcome this issue. This approach considers nonlinear behaviour of structures and not only is capable of detecting damaged elements but also can address the severity of imposed damages. Proposed algorithm was applied on a 3-story concrete building .The obtained results confirmed accuracy and robustness of this method.

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