scholarly journals Incremental Explosive Analysis and Its Application to Performance-Based Assessment of Stiffened and Unstiffened Cylindrical Shells Subjected to Underwater Explosion

2017 ◽  
Vol 2017 ◽  
pp. 1-17
Author(s):  
Masoud Biglarkhani ◽  
Keyvan Sadeghi
Keyword(s):  
Earthquake Engineering ◽  
Fragility Curves ◽  
Cylindrical Shells ◽  
Statistical Treatment ◽  
Underwater Explosion ◽  
Loading Conditions ◽  
Limit States ◽  
Buckling Modes ◽  
Damage Probability ◽  
Performance Based Assessment

Incremental explosive analysis (IEA) is addressed as an applicable method for performance-based assessment of stiffened and unstiffened cylindrical shells subjected to underwater explosion (UNDEX) loading. In fact, this method is inspired by the incremental dynamic analysis (IDA) which is a known parametric analysis method in the field of earthquake engineering. This paper aims to introduce the application of IEA approach in UNDEX in order to estimate different limit states and deterministic assessment of cylindrical shells, considering the uncertainty of loading conditions. The local, bay, and general buckling modes are defined as limit states for performance calculation. Different standoff distances and depth parameters combining several loading conditions are considered. The explosive loading intensity is specified and scaled in several levels to force the structure through the entire range of its behavior. The results are plotted in terms of a damage measure (DM) versus selected intensity measure (IM). The statistical treatment of the obtained multi-IEA curves is performed to summarize the results in a predictive mode. Finally, the fragility curves as damage probability indicators of shells in UNDEX loading are extracted. Results show that the IEA is a promising method for performance-based assessment of cylindrical shells subjected to UNDEX loading.

Seismic Fragility of Suspended Ceiling Systems

2007 ◽  
Vol 23 (1) ◽  
pp. 21-40 ◽  
Author(s):  
Hiram Badillo-Almaraz ◽  
Andrew S. Whittaker ◽  
Andrei M. Reinhorn
Keyword(s):  
Seismic Performance ◽  
Dynamic Testing ◽  
Fragility Curves ◽  
Full Scale ◽  
Seismic Fragility ◽  
Limit States ◽  
Performance Based Assessment ◽  
Damage States

Full-scale dynamic testing of suspended ceiling systems was performed to obtain fragility data suitable for performance-based assessment and design. On the basis of the fragility data derived from testing, (1) the use of retainer clips improves the performance of ceiling systems in terms of loss of tiles, (2) including recycled cross tees in the suspension grid increases the vulnerability of the ceiling systems, (3) undersized (poorly fitting) tiles are substantially more vulnerable than properly fitted tiles, and (4) the use of compression posts improves the seismic performance of ceiling systems for the limit states of minor and moderate damage. Fragility curves are provided for four damage states.

scholarly journals Lateral Seismic Fragility Assessment of Cable-Stayed Bridge with Diamond-Shaped Concrete Pylons

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Chao Zhang ◽  
Jianbin Lu ◽  
Zhengan Zhou ◽  
Xueyuan Yan ◽  
Li Xu ◽  
...  
Keyword(s):  
Fragility Curves ◽  
Damage Index ◽  
Element Model ◽  
Seismic Fragility ◽  
Limit States ◽  
Probabilistic Estimation ◽  
Cable Stayed Bridge ◽  
Damage Probability ◽  
Damage States ◽  
The Finite Element Model

The cable-stayed bridge with diamond-shaped pylons is one of the most popular bridges because of its obvious advantages such as aesthetical appearance and smaller foundation. However, the diamond-shaped pylons have both inward and outward inclinations, which may result in complicated seismic behavior when subjected to lateral earthquake excitations. To end this, the finite element model of a cable-stayed bridge with diamond concrete pylon is developed firstly. Four limit states and corresponding damage index are defined for each critical section. Finally, the lateral seismic fragility of the components and system of CSB was carried out. Based on the result of probabilistic estimation of lateral seismic responses, the order of the damage probability in all four damage states for each component of bridge is given. The fragility curves of bridge system on the lower bound and upper bound are studied. Moreover, the system fragility of the entire bridge is compared with that of each component.

Probabilistic Seismic Response of Coupled Tank-Piping Systems

2016 ◽  
Author(s):  
Giuseppe Abbiati ◽  
Oreste S. Bursi ◽  
Luca Caracoglia ◽  
Rocco Di Filippo ◽  
Vincenzo La Salandra
Keyword(s):  
Earthquake Engineering ◽  
Fragility Curves ◽  
Coupled Systems ◽  
Piping System ◽  
Actual Behavior ◽  
Limit States ◽  
Industrial Plants ◽  
Stochastic Linearization ◽  
Piping Systems ◽  
Performance Based Earthquake Engineering

Dynamic analysis is an integral part of seismic risk assessment of industrial plants. Such analysis often neglects proper coupling between structures of coupled systems, which introduces uncertainty into the system and may lead to erroneous results, e.g., incorrect fragility curves, in comparison with the actual behavior of the analyzed structure. Hence, it is important to study the effect of uncertainties on the dynamic characteristics of a system, when coupling effects are both neglected and included. Along this line, this paper intends to define and compare the fragility curves of both an isolated (decoupled) and a coupled tank-piping system subjected to seismic loading. In particular, for the decoupled case, we estimated the probability of exceedance of main engineering demand parameters within the Performance-Based Earthquake Engineering (PBEE) framework. Moreover, for the coupled case, to take into account the presence of the tank as boundary condition for the piping system, two sources of uncertainty were considered: i) the tank aspect ratio; ii) the piping-to-tank attachment height ratio. In addition, to model the tank slippage, both a Filtered White Noise (FWN) characterized by a Kanai-Tajimi spectrum and the non-stationarity of the seismic input were taken into account by means of the stochastic linearization. All these elements allow for the estimation of fragility curves for different limit states in the coupled case.

scholarly journals Displacement-Based Seismic Assessment of the Likelihood of Failure of Reinforced Concrete Wall Buildings

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 295
Author(s):  
Amirhossein Orumiyehei ◽  
Timothy J. Sullivan
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Concrete Wall ◽  
Limit States ◽  
Simplified Approach ◽  
Performance Based Assessment ◽  
Assessment Approach ◽  
Reinforced Concrete Wall ◽  
Displacement Based ◽  
Assessment Procedures

To strengthen the resilience of our built environment, a good understanding of seismic risk is required. Probabilistic performance-based assessment is able to rigorously compute seismic risk and the advent of numerical computer-based analyses has helped with this. However, it is still a challenging process and as such, this study presents a simplified probabilistic displacement-based assessment approach for reinforced concrete wall buildings. The proposed approach is trialed by applying the methodology to 4-, 8-, and 12-story case study buildings, and results are compared with those obtained via multi-stripe analyses, with allowance for uncertainty in demand and capacity, including some allowance for modeling uncertainty. The results indicate that the proposed approach enables practitioners to practically estimate the median intensity associated with exceeding a given mechanism and the annual probability of exceeding assessment limit states. Further research to extend the simplified approach to other structural systems is recommended. Moreover, the research highlights the need for more information on the uncertainty in our strength and deformation estimates, to improve the accuracy of risk assessment procedures.

scholarly journals Vulnerability Assessment of Buildings due to Land Subsidence Using InSAR Data in the Ancient Historical City of Pistoia (Italy)

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2749 ◽  
Author(s):  
Pablo Ezquerro ◽  
Matteo Del Soldato ◽  
Lorenzo Solari ◽  
Roberto Tomás ◽  
Federico Raspini ◽  
...  
Keyword(s):  
Fragility Curves ◽  
Central Italy ◽  
Sar Interferometry ◽  
Ground Subsidence ◽  
Public And Private ◽  
Radar Images ◽  
Spatial Deformation ◽  
Damage Probability ◽  
Medium Resolution ◽  
Vertical Displacements

The launch of the medium resolution Synthetic Aperture Radar (SAR) Sentinel-1 constellation in 2014 has allowed public and private organizations to introduce SAR interferometry (InSAR) products as a valuable option in their monitoring systems. The massive stacks of displacement data resulting from the processing of large C-B and radar images can be used to highlight temporal and spatial deformation anomalies, and their detailed analysis and postprocessing to generate operative products for final users. In this work, the wide-area mapping capability of Sentinel-1 was used in synergy with the COSMO-SkyMed high resolution SAR data to characterize ground subsidence affecting the urban fabric of the city of Pistoia (Tuscany Region, central Italy). Line of sight velocities were decomposed on vertical and E–W components, observing slight horizontal movements towards the center of the subsidence area. Vertical displacements and damage field surveys allowed for the calculation of the probability of damage depending on the displacement velocity by means of fragility curves. Finally, these data were translated to damage probability and potential loss maps. These products are useful for urban planning and geohazard management, focusing on the identification of the most hazardous areas on which to concentrate efforts and resources.

scholarly journals Seismic Assessment of Arch Dams Using Fragility Curves

2015 ◽  
Vol 1 (2) ◽  
pp. 14-20 ◽  
Author(s):  
Vandad Kadkhodayan ◽  
S. Meisam Aghajanzadeh ◽  
Hasan Mirzabozorg
Keyword(s):  
Fragility Curves ◽  
Routine Data ◽  
Seismic Assessment ◽  
Arch Dam ◽  
The Other ◽  
Intensity Measure ◽  
Limit States ◽  
High Arch Dam ◽  
Arch Dams ◽  
Engineering Demand Parameter

In the present paper, the IDA approach is applied to analyzing a thin high arch dam. The parameters of Sa, PGA and PGV are used as intensity measure (IM) and the overstressed area (OSA) is utilized as engineering demand parameter (EDP) and then, three limit states are assigned to the considered structure using the IDA curves. Subsequently, fragility curves are calculated and it is showed that the PGA is a better parameter to be taken as IM. In addition, it is found that the utilizing the proposed methodology, quantifying the qualitative limit states is probable. At last, having the fragility curves and considering their slope in addition to the other routine data which can be extracted from these curves, one may be able to conclude that in what performance level the considered dam body seems to be weak and needs retrofitting works.

DEM Simulations in Geotechnical Earthquake Engineering Education

2012 ◽  
pp. 100-109
Author(s):  
J. S. Vinod
Keyword(s):  
Engineering Education ◽  
Granular Materials ◽  
Earthquake Engineering ◽  
Laboratory Experiments ◽  
Computational Models ◽  
Cyclic Behavior ◽  
Advanced Mathematics ◽  
Loading Conditions ◽  
Geotechnical Earthquake Engineering ◽  
Element Method

Behaviour of geotechnical material is very complex. Most of the theoretical frame work to understand the behaviour of geotechnical materials under different loading conditions depends on the strong background of the basic civil engineering subjects and advanced mathematics. However, it is fact that the complete behaviour of geotechnical material cannot be traced within theoretical framework. Recently, computational models based on Finite Element Method (FEM) are used to understand the behaviour of geotechnical problems. FEM models are quite complex and is of little interest to undergraduate students. A simple computational tool developed using Discrete Element Method (DEM) to simulate the laboratory experiments will be cutting edge research for geotechnical earthquake engineering education. This article summarizes the potential of DEM to simulate the cyclic triaxial behaviour of granular materials under complex loading conditions. It is shown that DEM is capable of simulating the cyclic behavior of granular materials (e.g. undrained, liquefaction and post liquefaction) similar to the laboratory experiments.

scholarly journals Seismic Fragility Analysis of Multispan Reinforced Concrete Bridges Using Mainshock-Aftershock Sequences

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yutao Pang ◽  
Li Wu
Keyword(s):  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Design Method ◽  
Fragility Curves ◽  
Uniform Design ◽  
Time History ◽  
Fragility Analysis ◽  
Nonlinear Time History Analysis ◽  
Aftershock Sequences ◽  
System Fragility

Although the knowledge and technology of performance-based earthquake engineering have rapidly advanced in the past several decades, current seismic design codes simply ignore the effect of aftershocks on the performance of structures. Thus, the present paper investigated the effect of aftershocks on seismic responses of multispan reinforced concrete (RC) bridges using the fragility-based numerical approach. For that purpose, a continuous girder RC bridge class containing 8 bridges was selected based on the statistical analysis of the existing RC bridges in China. 75 recorded mainshock-aftershock seismic sequences from 10 well-known earthquakes were selected in this study. In order to account for the uncertainty of modeling parameters, uniform design method was applied as the sampling method for generating the samples for fragility analysis. Fragility curves were then developed using nonlinear time-history analysis in terms of the peak curvature of pier column and displacement of bearings. Finally, the system fragility curves were derived by implementing Monte Carlo simulation on multinormal distribution of two components. From the results of this investigation, it was found that, for the RC continuous bridges, the influence of aftershocks can be harmful to both bridge components and system, which increases both the component fragility of the displacement of bearings and seismic curvature of pier sections and system fragility.

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