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earthquake-damage
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Machine learning-aided scenario-based seismic drift measurement for RC moment frames using visual features of surface damage
, Article Measurement: Journal of the International Measurement Confederation ; Volume 205 , 2022 ; 02632241 (ISSN) ; Mansourdehghan, S ; Asjodi, A. H ; Dolatshahi, K.M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
This paper presents a novel computer vision-based methodology for assessment of the seismic damage in reinforced concrete moment frames using visual characteristics of surface damage following an earthquake. An extensive collected database comprising 974 images associated with 256 cyclic-loaded damaged beam-column joints, providing a set of cracking and crushing progression with increasing the evolution of damage level, is collected and used for the development and validation of the methodology. Employing image processing techniques, the characteristics of the surface damage, including the cracking length and crushing areas, are measured and used in a scenario-based assessment for the...
Probabilistic Framework to Quantify the Resilience of Urban Gas Distribution Networks
, M.Sc. Thesis Sharif University of Technology ; Kashani, Hamed (Supervisor)
Abstract
This study proposes a probabilistic framework to quantify the seismic resilience of urban natural gas distribution networks. Infrastructure resilience is defined as the ability to maintain performance after a hazard or, in case of a loss of performance, return to the minimum desired level in the optimal time. The framework presented in this research is comprised of multiple interconnected probabilistic models. These models work in harmony to characterize the impact of the earthquake on various infrastructures such as the buildings and urban gas distribution network components, as well as the probable consequences of the earthquake. The post-earthquake recovery of the gas distribution network...
Failure risk assessment of interdependent infrastructures against earthquake, a Petri net approach: Case study-power and water distribution networks
, Article Natural Hazards ; Vol. 71, issue. 3 , April , 2014 , pp. 1971-1993 ; ISSN: 0921030X ; Hojjati Malekshah, M ; Omidvar, H ; Sharif University of Technology
Abstract
Metropolitan areas consist of complicated systems of interconnected infrastructures that are highly interdependent. Disruption of one infrastructure may induce disruption in other interconnected ones. The results from analysis of one infrastructure as an independent system are not realistic without considering the behavior of other interconnected infrastructures. Consequently, the study of the interdependencies among critical infrastructures is important for addressing the cascading effects of a failed infrastructure on the entire network to properly model its performance and help the disaster management team in decision making. In this study, the extended Petri net and Markov chain have...
The effect of soil-structure interaction on damage index of buildings
, Article Engineering Structures ; Volume 30, Issue 6 , 2008 , Pages 1491-1499 ; 01410296 (ISSN) ; Ali Ghannad, M ; Sharif University of Technology
2008
Abstract
The effect of Soil-Structure Interaction (SSI) on Park and Ang Damage Index in a Bilinear-SDOF model is investigated under seismic loading. This is done through an extensive parametric study. Two non-dimensional parameters are used as the key parameters which control the severity of SSI: (1) a non-dimensional frequency as the structure-to-soil stiffness ratio index and (2) the aspect ratio of the structure. The soil beneath the structure is considered as a homogeneous elastic half space and is modeled using the concept of Cone Models. The system is then subjected to three different earthquake ground motions as the representative motions recorded on different soil conditions. The analysis is...
Evaluation of a robust dynamic vibration absorber based on negative stiffness and internal resonance against seismic excitation
, Article International Journal of Non-Linear Mechanics ; Volume 146 , 2022 ; 00207462 (ISSN) ; Attari, N. K. A ; Rofooei, F. R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
In this study, a nonlinear absorber that works with a negative stiffness is introduced to control vibration and its effect on reducing earthquake damage is investigated. Negative stiffness increases structural softness and damping. Also, due to its inherent nonlinear nature, negative stiffness can cause internal resonance and transfer vibration energy from a directly excited vibrating mode to a higher frequency mode. Using these features can be effective in reducing vibration. First, to investigate the dynamic behavior in conditions without internal resonance and with 1:3 internal resonance, the proposed absorber is added to a nonlinear main system and when the system is under external...
Probabilistic evaluation of seismic design parameters of RC frames based on fragility curves
, Article Scientia Iranica ; Volume 20, Issue 2 , 2013 , Pages 231-241 ; 10263098 (ISSN) ; Asadi, P ; Sharif University of Technology
2013
Abstract
There are many parameters utilized to obtain a more reasonable performance for structures under earthquake excitations in seismic provisions. General considered parameters in seismic provisions are: PGA, importance factor (I) and typical inherent overstrength and global ductility capacity (R). It is well recognized that the main characteristic of the design of structures under seismic excitation is probabilistic rather than deterministic; therefore, it should be determined if whether the probability of structural damage decreases when such parameters change in the design of structures. In this paper, fragility curves are developed in order to evaluate these parameters. Fragility curves are...
The effect of soil–structure interaction on the seismic risk to buildings
, Article Bulletin of Earthquake Engineering ; Volume 16, Issue 9 , 2018 , Pages 3653-3673 ; 1570761X (ISSN) ; Mahsuli, M ; Ghannad, M. A ; Sharif University of Technology
Springer Netherlands
2018
Abstract
This paper studies the effect of soil–structure interaction (SSI) on the seismic risk estimates of buildings. Risk, in this context, denotes the probability distribution of seismic monetary loss due to structural and nonstructural damage. The risk analysis here uncovers the probability that SSI is beneficial, detrimental, or uninfluential on seismic losses. The analyses are conducted for a wide range of buildings with different structural systems, numbers of stories, and foundation sizes on various soil types. A probabilistic approach is employed to account for prevailing sources of uncertainty, i.e., those in ground motion and in the properties of the soil–structure system. In this...
Correlation between structural performance levels and damage indexes in steel frames subjected to earthquakes
, Article Scientia Iranica ; Volume 16, Issue 2 A , 2009 , Pages 147-155 ; 10263098 (ISSN) ; Estekanchi, H ; Vafai, A ; Sharif University of Technology
2009
Abstract
Various damage indexes have been introduced in recent years incorporating different parameters for estimating structural damage. Amongst these indexes, Plastic Ductility and Drift have been the center of attention of standards and building codes, like FEMA-356, because of their straightforward physical interpretation and ease of calculation. In this paper, several steel moment frames have been considered and their responses have been evaluated under a set of scaled earthquakes. A group of various damage indexes, which included cumulative and non cumulative, cyclic fatigue based, deformation based and modal parameter based, has been considered and the damage to structures has been evaluated...
Seismic analysis of arch dams using anisotropic damage-plastic model for concrete with coupled adhesive-frictional joints response
, Article Soil Dynamics and Earthquake Engineering ; Volume 125 , 2019 ; 02677261 (ISSN) ; Ghaemian, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
A finite element model for seismic analysis of concrete arch dams is proposed. Material inelasticity as well as joints nonlinearity is considered. A damage-plastic formulation governs nonlinear behavior of concrete. Degeneration occurring during nonlinear behavior of concrete induces anisotropy into its microstructure. This anisotropy becomes more complex in seismic simulations, in which the state of stress expeditiously changes with time. Thus, anisotropic formulation is preferred over classical isotropic models. Utilizing rate-dependent anisotropic damage-plastic model, irreversible deformations, stiffness degeneration, induced anisotropy, closing/reopening of cracks, and viscous response...
Predictive equations for drift ratio and damage assessment of RC shear walls using surface crack patterns
, Article Engineering Structures ; Volume 190 , 2019 , Pages 410-421 ; 01410296 (ISSN) ; Dolatshahi, K. M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The purpose of this paper is to quantify the extent of damage of rectangular reinforced concrete shear walls after an earthquake using surface crack patterns. One of the most important tasks after an earthquake is to assess the safety and classify the performance level of buildings. This assessment is usually performed by visual inspection that is prone to significant errors. In this research, an extensive database on the images of damaged rectangular reinforced concrete shear walls is collected from the literature. This database includes more than 200 images from experimental quasi-static cyclic tests. Using the concept of fractal geometry, several probabilistic models are developed by...
Performance evaluation of masonry buildings using a probabilistic approach
, Article Scientia Iranica ; Volume 15, Issue 3 , 2008 , Pages 295-307 ; 10263098 (ISSN) ; Karimi, K ; Sharif University of Technology
Sharif University of Technology
2008
Abstract
In many countries, there are traditional houses made of stone, adobe and brick, which perform relatively weakly in earthquakes. To mitigate casualties in future earthquakes, it is necessary to evaluate the current status of these buildings and propose effective methods to retrofit them. One method of evaluating the performance of buildings in earthquakes is through the use of fragility curves. These diagrams show the probability of exceeding a specific state of damage versus seismic intensity parameters, such as PGA, MMI, la, CAV etc. Fragility curves will provide an important basis for analytical methods, based on probabilistic approaches. Much work has been done on bridges, concrete and...
Seismic performance and fragility analysis of power distribution concrete poles
, Article Soil Dynamics and Earthquake Engineering ; Volume 150 , 2021 ; 02677261 (ISSN) ; Mahsuli, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
This paper proposes probabilistic damage and collapse models for reinforced concrete poles in electric power distribution networks and investigates the damage and collapse pattern of poles under earthquake excitations. To this end, detailed finite element models of the H-type reinforced concrete poles are developed and verified using past experimental studies as well as the observed damage in previous earthquakes. The models are then subjected to nonlinear static analyses to study the effect of the loading pattern, loading direction, concrete strength, and failure criteria on the capacity and the collapse pattern of the pole. Next, incremental dynamic analysis is carried out to investigate...
Seismic reliability analysis of steel moment-resisting frames retrofitted by vertical link elements using combined series–parallel system approach
, Article Bulletin of Earthquake Engineering ; Volume 19, Issue 2 , 2021 , Pages 831-862 ; 1570761X (ISSN) ; Hajirasouliha, I ; Filizadeh, R ; Sharif University of Technology
Springer Science and Business Media B.V
2021
Abstract
The eccentric bracing system equipped with vertical links is capable of providing high levels of stiffness, strength and ductility, and therefore, can be efficiently used for seismic retrofit of existing structures. This study aims to investigate the seismic reliability of steel moment-resisting frames retrofitted by this system using a novel combined series–parallel system approach. The seismic response of 4, 8 and 12-storey steel moment-resisting frames (MRFs) are evaluated under a set of design basis earthquakes (DBE) before and after retrofitting intervention. Adopting an engineering demand parameter approach (EDP-Based) for reliability assessment and development of analytical models for...
A resilience-based practical platform and novel index for rapid evaluation of urban water distribution network using hybrid simulation
, Article Sustainable Cities and Society ; Volume 82 , 2022 ; 22106707 (ISSN) ; Mortaheb, M. M ; Hassani, N ; Taghizadeh yazdi, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
This article proposes a novel index along with a user-friendly platform for resilience evaluation of the urban water distribution networks (WDN). WDN is of great importance in preserving the safety and sustainability of communities and cities. Resilience of a given system results in its sustainability. In recent years, many studies have focused on resilient urban WDN. However, these studies did not provide a comprehensive evaluation index and platform that could simultaneously consider hydraulic analysis, resilience parameters, and significant uncertainties. In this study, a novel resilience index was defined, and a user-friendly and practical platform (REWAT) was developed to calculate the...
Peak drift ratio estimation for unreinforced masonry walls using visual features of damage
, Article Bulletin of Earthquake Engineering ; Volume 20, Issue 15 , 2022 , Pages 8357-8379 ; 1570761X (ISSN) ; Dolatshahi, K. M ; Sharif University of Technology
Springer Science and Business Media B.V
2022
Abstract
This study proposes predictive equations for estimating the peak-experienced drift ratio of unreinforced masonry walls based on the visual characteristic of the damages. In this regard, a comprehensive database comprised of 190 images associated with 30 unreinforced masonry walls at different drift ratios between 0.0 and 1.1 percent is collected, and the visual features of the progressive damages are extracted. Various image processing filters are implemented to the images to quantify the cracking length and crushing areas. The filters are capable of distinguishing different crack patterns, such as joint cracking and block cracking. In the following, four scenarios are introduced based on...