scholarly journals Assessment of Seismic Vulnerability of Steel and RC Moment Buildings Using HAZUS and Statistical Methodologies

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Iman Mansouri ◽  
Jong Wan Hu ◽  
Kazem Shakeri ◽  
Shahrokh Shahbazi ◽  
Bahareh Nouri
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Moment Frames ◽  
Limit States ◽  
Rc Frames ◽  
Dynamic Analyses ◽  
Damage States ◽  
Definition Of ◽  
Nonlinear Dynamic Analyses

Designer engineers have always the serious challenge regarding the choice of the kind of structures to use in the areas with significant seismic activities. Development of fragility curve provides an opportunity for designers to select a structure that will have the least fragility. This paper presents an investigation into the seismic vulnerability of both steel and reinforced concrete (RC) moment frames using fragility curves obtained by HAZUS and statistical methodologies. Fragility curves are employed for several probability parameters. Fragility curves are used to assess several probability parameters. Furthermore, it examines whether the probability of the exceedence of the damage limit state is reduced as expected. Nonlinear dynamic analyses of five-, eight-, and twelve-story frames are carried out using Perform 3D. The definition of damage states is based on the descriptions provided by HAZUS, which gives the limit states and the associated interstory drift limits for structures. The fragility curves show that the HAZUS procedure reduces probability of damage, and this reduction is higher for RC frames. Generally, the RC frames have higher fragility compared to steel frames.

scholarly journals Probabilistic Risk-Based Performance Evaluation of Seismically Base-Isolated Steel Structures Subjected to Far-Field Earthquakes

Buildings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 128 ◽  
Author(s):  
Aryan Rezaei Rad ◽  
Mehdi Banazadeh
Keyword(s):  
Fragility Curves ◽  
Steel Structures ◽  
Superior Performance ◽  
Far Field ◽  
Structural Components ◽  
Moment Frames ◽  
Damage States ◽  
Nonlinear Dynamic Analyses ◽  
Rubber Bearings ◽  
Maximum Earthquake

The performance of base-isolated steel structures having special moment frames is assessed. The archetypes, which are designed per ASCE/SEI 7–2016, are simulated in the Finite Element (FE) computational platform, OpenSees. Adopting nonlinear dynamic analyses using far-field ground motions, the performance of Drift-Sensitive Structural Components (DS-SC), and Drift-/Acceleration-Sensitive Non-Structural Components (DS/AS NSC) at slight, moderate, extensive, and collapse damage states are investigated. The effects of structural height, effective transformed period (Teff), response modification coefficient (RI), and isolation type on the performance of 26 archetypes mounted on Lead Rubber Bearings (LRBs) and Triple Concave Friction Pendulums (TCFPs) are evaluated. Computing 50-year probability of exceedance using the fragility curves and seismic hazard curves of the site, increasing Teff reduces the role of RI in the structural performance; variations in the height, as well as RI, do not affect the risk of damages to the AS-NSC; the risk of collapse is not sensitive to the variations of Teff. The TCFP systems represent superior performance than LRB systems in lower intensities. For longer periods and taller structures, the isolation type has less effect on the performance of NSC. Finally, the archetypes have less than 1% risk of collapse in 50 years; nevertheless, high-rise structures with RI = 2.0 have more than 10% probability of collapse given the maximum earthquake.

Displacement-Based Fragility Curves for Seismic Assessment of Adobe Buildings in Cusco, Peru

2012 ◽  
Vol 28 (2) ◽  
pp. 759-794 ◽  
Author(s):  
Nicola Tarque ◽  
Helen Crowley ◽  
Rui Pinho ◽  
Humberto Varum
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Limit State ◽  
Seismic Demand ◽  
Limit States ◽  
Plane Failure ◽  
Displacement Capacity ◽  
Out Of Plane ◽  
Displacement Based

The seismic vulnerability of single-story adobe dwellings located in Cusco, Peru, is studied based on a mechanics-based procedure, which considers the analysis of in-plane and out-of-plane failure mechanisms of walls. The capacity of each dwelling is expressed as a function of its displacement capacity and period of vibration and is evaluated for different limit states to damage. The seismic demand has been obtained from several displacement response spectral shapes. From the comparison of the capacity with the demand, probabilities of limit state exceedance have been obtained for different PGA values. The results indicate that fragility curves in terms of PGA are strongly influenced by the response spectrum shape; however, this is not the case for the derivation of fragility curves in terms of limit state spectral displacement. Finally, fragility curves for dwellings located in Pisco, Peru, were computed and the probabilities of limit state exceedance were compared with the data obtained from the 2007 Peruvian earthquake.

Reliability Analysis of Seismic Isolation in Retrofitting of Simply Supported Bridges

2016 ◽  
Vol 847 ◽  
pp. 391-400
Author(s):  
Luigi Petti ◽  
Alessio Lodato ◽  
Angelo Mammone
Keyword(s):  
Seismic Isolation ◽  
Fragility Curves ◽  
Seismic Intensity ◽  
Finite Element Models ◽  
Design Strategies ◽  
Limit States ◽  
Damage Level ◽  
Simply Supported ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses

The paper investigates the reliability of simply supported bridges, retrofitted or less with seismic isolation, by means of fragility curves, which represent the probability of reaching a certain damage level for an assigned seismic intensity. Taking advantage of the Multi Stripes methodology, several nonlinear dynamic analyses of a multi-span bridge representing the existing ones in Italy built in the 60 ' characterized by means of non linear finite element models in different design configurations of seismic retrofit have been carried out, in order to obtain the fragility functions.The obtained results allow to assess the isolation retrofit strategies effectiveness to mitigate the seismic risk of simply supported bridges, highlighting the influence of different design strategies on the probability of exceeding the limit states considered.

scholarly journals The Role of Soil Structure Interaction in the Fragility Assessment of HP/HT Unburied Subsea Pipelines

2022 ◽  
Vol 10 (1) ◽  
pp. 110
Author(s):  
Davide Forcellini ◽  
Daniele Mina ◽  
Hassan Karampour
Keyword(s):  
Soil Structure ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Failure Criteria ◽  
Soil Structure Interaction ◽  
Limit States ◽  
Structure Interaction ◽  
Definition Of ◽  
Subsea Pipelines

Subsea high pressure/high temperature (HP/HT) pipelines may be significantly affected by the effects of soil structure interaction (SSI) when subjected to earthquakes. Numerical simulations are herein applied to assess the role of soil deformability on the seismic vulnerability of an unburied pipeline. Overcoming most of the contributions existing in the literature, this paper proposes a comprehensive 3D model of the system (soil + pipeline) by performing OpenSees that allows the representation of non-linear mechanisms of the soil and may realistically assess the induced damage caused by the mutual interaction of buckling and seismic loads. Analytical fragility curves are herein derived to evaluate the role of soil structure interaction in the assessment of the vulnerability of a benchmark HP/HT unburied subsea pipeline. The probability of exceeding selected limit states was based on the definition of credited failure criteria.

scholarly journals Mechanical-Analytical Soil-Dependent Fragility Curves of Existing RC Frames with Column-Driven Failures

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 278
Author(s):  
Raihan Rahmat Rabi ◽  
Vincenzo Bianco ◽  
Giorgio Monti
Keyword(s):  
Risk Estimation ◽  
Fragility Curves ◽  
Local Level ◽  
Rapid Development ◽  
Limit State ◽  
Critical Issue ◽  
Structural Level ◽  
Limit States ◽  
Rc Frames ◽  
Interstorey Drift

In seismic risk estimation, among the different types of fragility curves used (judgement-based, mechanical, empirical/observational, hybrid), the mechanical ones have the twofold advantage of allowing a better control over the basic parameters and of representing a validation test of the consistency of empirical/observational ones. In this study, fragility curves of RC frames with column-driven failures are obtained from a simplified analytical pushover method implemented in a simple spreadsheet, thus allowing the user to perform a large number of analyses. More importantly, the proposed method introduces the concept that Limit States at the structural level are obtained consequent to the attainment of the same Limit States at the local level, in the columns’ sections. This avoids using additional criteria, such as interstorey drift thresholds. This simple analytical model allows for rapid development of fragility curves, for any Limit State, of different building typologies identified by a set of global quantities (number of storeys, story heights, number of spans and span lengths) and by a set of local quantities (element sizes, reinforcement, and material properties). It also allows for a straightforward treatment of the influence of the soil class on the fragility curves parameters, which is another critical issue addressed in this work that helps when interpreting some literature results using empirical/observational methods.

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.

Seismic risk assessment of RC curved bridges through fragility curves

2019 ◽  
Author(s):  
Nina N. Serdar ◽  
Jelena R. Pejovic ◽  
Radenko Pejovic ◽  
Miloš Knežević
Keyword(s):  
Risk Assessment ◽  
Urban Areas ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Curved Bridges ◽  
Damage State ◽  
Seismic Risk Assessment ◽  
Probability Of Exceedance ◽  
Damage States

<p>It is of great importance that traffic network is still functioning in post- earthquake period, so that interventions in emergency situations are not delayed. Bridges are part of the traffic system that can be considered as critical for adequate post-earthquake response. Their seismic response often dominate the response and reliability of overall transportation system, so special attention should be given to risk assessment for these structures. In seismic vulnerability and risk assessment bridges are often classified as regular or irregular structures, dependant on their configuration. Curved bridges are considered as irregular and unexpected behaviour during seismic excitation is noticed in past earthquake events. Still there are an increasing number of these structures especially in densely populated urban areas since curved configuration is often suitable to accommodate complicated location conditions. In this paper special attention is given to seismic risk assessment of curved reinforce concrete bridges through fragility curves. Procedure for developing fragility curves is described as well as influence of radius curvature on their seismic vulnerability is investigated. Since vulnerability curves provide probability of exceedance of certain damage state, four damage states are considered: near collapse, significant damage, intermediate damage state, onset of damage and damage limitation. As much as possible these damage states are related to current European provisions. Radius of horizontal curvature is varied by changing subtended angle: 25 °, 45 ° and 90 °. Also one corresponding straight bridge is analysed. Nonlinear static procedure is used for developing of fragility curves. It was shown that probability of exceedance of certain damage states is increased as subtended angle is increased. Also it is determined that fragility of curved bridges can be related to fragility of straight counterparts what facilitates seismic evaluation of seismic vulnerability of curved bridges structures.</p>

scholarly journals Fragility Assessment of a Container Crane under Seismic Excitation Considering Uplift and Derailment Behavior

2019 ◽  
Vol 9 (21) ◽  
pp. 4660
Author(s):  
Quang Huy Tran ◽  
Jungwon Huh ◽  
Nhu Son Doan ◽  
Van Ha Mac ◽  
Jin-Hee Ahn
Keyword(s):  
Structural Damage ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Seismic Excitation ◽  
Damage State ◽  
Limit States ◽  
Container Crane

While the container crane is an important part of daily port operations, it has received little attention in comparison with other infrastructures such as buildings and bridges. Crane collapses owing to earthquakes affect the operation of the port and indirectly impact the economy. This study proposes fragility analyses for various damage levels of a container crane, thus enabling the port owner and partners to better understand the seismic vulnerability presented by container cranes. A large number of nonlinear time-history analyses were applied for a three-dimensional (3D) finite element model to quantify the vulnerability of a Korean case-study container crane considering the uplift and derailment behavior. The uncertainty of the demand and capacity of the crane structures were also considered through random variables, i.e., the elastic modulus of members, ground motion profile, and intensity. The results analyzed in the case of the Korean container crane indicated the probability of exceeding the first uplift with or without derailment before the crane reached the structure’s limit states. This implies that under low seismic excitation, the crane may be derailed without any structural damage. However, when the crane reaches the minor damage state, this condition is always coupled with a certain probability of uplift with or without derailment. Furthermore, this study proposes fragility curves developed for different structural periods to enable port stakeholders to assess the risk of their container crane.

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):  
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.

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