scholarly journals Seismic Vulnerability Assessment of a Reinforced Concrete Building Located in India

2019 ◽  
Vol 8 (11S) ◽  
pp. 310-314
Keyword(s):  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Equivalent Linearization ◽  
Spectral Acceleration ◽  
Damage State ◽  
Ground Acceleration ◽  
Seismic Vulnerability Assessment ◽  
Performance Point ◽  
Damage States

Over the recent years the natural disaster especially due to the earthquake effect on buildings increases which causes loss of life and property in many places all over the world. The latest development leads to finding the direct losses and damage states of the buildings for various intensities of earthquake ground motions. In the present study, seismic vulnerability assessment was done for a medium rise building (G+5). The design peak ground acceleration of 0.16g and 0.36g were considered for the risk assessment. The nonlinear static pushover analysis was done to fine the performance point, spectral acceleration and corresponding spectral acceleration by Equivalent Linearization (EL) method given by Federal Emergency Management Agency (FEMA-440). The four damage states such as slight, moderate, extreme and collapse has been considered as per HAZUS-MR4. The seismic vulnerability in terms of fragility curves was developed to evaluate the damage probabilities based on HAZUS methodology. The discrete and cumulative damage probability was found for all the damage states of the building which shows the building at 0.16g experience slight damage whereas at 0.36g the moderate damage state equally becomes predominant.

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 Seismic Vulnerability Assessment and Mapping of Gyeongju, South Korea Using Frequency Ratio, Decision Tree, and Random Forest

2020 ◽  
Vol 12 (18) ◽  
pp. 7787 ◽  
Author(s):  
Jihye Han ◽  
Jinsoo Kim ◽  
Soyoung Park ◽  
Sanghun Son ◽  
Minji Ryu
Keyword(s):  
Random Forest ◽  
Decision Tree ◽  
South Korea ◽  
Vulnerability Assessment ◽  
Seismic Data ◽  
Frequency Ratio ◽  
Seismic Vulnerability ◽  
Success Rates ◽  
Ground Acceleration ◽  
Seismic Vulnerability Assessment

The main purpose of this study was to compare the prediction accuracies of various seismic vulnerability assessment and mapping methods. We applied the frequency ratio (FR), decision tree (DT), and random forest (RF) methods to seismic data for Gyeongju, South Korea. A magnitude 5.8 earthquake occurred in Gyeongju on 12 September 2016. Buildings damaged during the earthquake were used as dependent variables, and 18 sub-indicators related to seismic vulnerability were used as independent variables. Seismic data were used to construct a model for each method, and the models’ results and prediction accuracies were validated using receiver operating characteristic (ROC) curves. The success rates of the FR, DT, and RF models were 0.661, 0.899, and 1.000, and their prediction rates were 0.655, 0.851, and 0.949, respectively. The importance of each indicator was determined, and the peak ground acceleration (PGA) and distance to epicenter were found to have the greatest impact on seismic vulnerability in the DT and RF models. The constructed models were applied to all buildings in Gyeongju to derive prediction values, which were then normalized to between 0 and 1, and then divided into five classes at equal intervals to create seismic vulnerability maps. An analysis of the class distribution of building damage in each of the 23 administrative districts showed that district 15 (Wolseong) was the most vulnerable area and districts 2 (Gangdong), 18 (Yangbuk), and 23 (Yangnam) were the safest areas.

Large-Scale Seismic Vulnerability Assessment Method for Urban Centres. An Application to the City of Florence

2014 ◽  
Vol 628 ◽  
pp. 49-54 ◽  
Author(s):  
Maurizio Ripepe ◽  
Giorgio Lacanna ◽  
Pauline Deguy ◽  
Mario de Stefano ◽  
Valentina Mariani ◽  
...  
Keyword(s):  
Vulnerability Assessment ◽  
Large Scale ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Structural Features ◽  
Assessment Method ◽  
Ground Acceleration ◽  
Seismic Vulnerability Assessment ◽  
Damage Scenarios ◽  
The City

The seismic vulnerability assessment of a building requires a comprehensive knowledge of both building structural features and soils geophysical parameters. To achieve a vulnerability assessment at the urban scale a large amount of data would be necessary, with a consequent involvement of time and economical resources. The aim of this paper is hence to propose a simplified procedure to evaluate the seismic vulnerability of urban centres and possible seismic damage scenarios in order to identify critical areas and/or building typologies to plan future actions of seismic risk mitigation and prevention. The procedure is applied to the outstanding case study of the city of Florence. The research is based on the definition of major building typologies related to construction periods and type of the structural system (masonry or reinforced concrete), the identification of a set of sample buildings, the analysis of the dynamic behaviour and the evaluation of a vulnerability index with an expeditious approach. The obtained results allow to define potential vulnerability and post-event damage scenarios related to the expected levels of peak ground acceleration.

scholarly journals Seismic vulnerability assessment of a high-rise molten-salt solar tower based on incremental dynamic analysis

2020 ◽  
Vol 194 ◽  
pp. 01005
Author(s):  
Weiwei Sun ◽  
Dina D’Ayala ◽  
Jinxing Fu ◽  
Wentao Gu ◽  
Jun Feng
Keyword(s):  
Dynamic Analysis ◽  
Molten Salt ◽  
Seismic Performance ◽  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Incremental Dynamic Analysis ◽  
Seismic Excitations ◽  
Ground Acceleration ◽  
Seismic Vulnerability Assessment ◽  
High Rise

This paper investigates the seismic performance of a high-rise molten-salt solar tower by finite element modelling. The integrated and separated models for solar tower based on the concrete damage plastic model are validated by matching the behaviour of similar reinforced concrete chimney specimens. The modal analysis demonstrates the first four modes of the solar tower are translational vibration. Seismic simulations are developed through the incremental dynamic analysis. The most disadvantageous position of the tower is all concentrated in the opening section under multidirectional seismic excitations. The top displacement of the tower under bidirectional and three-directional earthquake actions is larger than that under unidirectional earthquake actions. The results of the seismic vulnerability assessment show that when the PGA equals to 0.035g, the tower will be intact; when the PGA equals to 0.1g (design peak ground acceleration), the probability of the moderate damage state is within 1.5%; when the PGA equals to 0.22g (maximum considered earthquake), the probability of the destruction state is below 0.7%. The seismic partitioned fragility analysis of the tower under multidirectional earthquake excitations illustrates that there are two peaks in the vulnerability surfaces. The anti-collapse analysis indicates the tower has a good seismic performance under multidirectional seismic excitations.

Seismic Fragility Curves for On-Grade Steel Tanks

2000 ◽  
Vol 16 (4) ◽  
pp. 801-815 ◽  
Author(s):  
Michael J. O'Rourke ◽  
Pak So
Keyword(s):  
Fragility Curves ◽  
Damage State ◽  
Ground Acceleration ◽  
Technical Literature ◽  
Ground Shaking ◽  
Liquid Storage ◽  
Damage States ◽  
Earthquake Loss ◽  
Steel Tanks ◽  
Grade Steel

The study reported herein attempts to characterize the seismic behavior of cylindrical on-grade, steel liquid storage tanks subject to the ground shaking hazard. The behavior is quantified by fragility curves that resulted from an analysis of the reported performance of over 400 tanks in nine separate earthquake events. The damage states used herein to characterize damage (i.e., slight, moderate, etc.) are intended to mirror damage state descriptions in the HAZUS Earthquake Loss Estimation Methodology. The amount of ground shaking is quantified by the peak ground acceleration (PGA) at the site. The influence of the tank's height to diameter ratio, H/D, as well as the relative amount of stored contents, % Full, are investigated and were found to have had a significant effect upon tank seismic performance. Finally, the fragility curves developed herein are compared to corresponding relations currently available in the technical literature.

Ground Motion Intensity Measures for Seismic Vulnerability Assessment of Steel Storage Tanks with Unanchored Support Conditions

2021 ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci ◽  
Van My Nguyen ◽  
Phuong Hoa Hoang
Keyword(s):  
Comparative Study ◽  
Ground Motion ◽  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Superior Performance ◽  
Spectral Acceleration ◽  
Storage Tanks ◽  
Intensity Measures ◽  
Seismic Vulnerability Assessment ◽  
Support Conditions

Abstract This paper aims to comprehensively evaluate the performance of a series of ground motion intensity measures (IMs) used in the seismic vulnerability assessment of steel storage tanks with unanchored support conditions. Sixteen well-known IMs are thus selected, which are classified into amplitude-, frequency-, and time-based categories. A comparative study is then performed on four different unanchored steel storage tanks subjected to a suite of 140 ground motion records that is comprised of seven different bins of records with different hazard levels. In this regard, the tanks are appropriately modeled based on a simplified approach, whose uplift and sliding nonlinear behaviors are properly implemented based on a three-dimensional nonlinear pushover analysis of the tanks. Four characteristics of the examined IMs including efficiency, practicality, proficiency, and sufficiency are evaluated based on a probabilistic seismic demand model of two critical failure modes of the tanks, i.e., plastic rotation of the shell-to-bottom connection and elephant's foot buckling of the shell plate. According to the comparative study, frequency-based IMs demonstrate their superior performance for all criteria compared with other groups; in particular, the average spectral acceleration gains the highest ranking. Finally, an appropriate range of the upper period considered in the average spectral acceleration IM is then proposed to optimize the efficiency of this IM for the examined tanks.

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