Ahmed MEBARKI - Profile on Academia.edu (original) (raw)

Papers by Ahmed MEBARKI

A construction guideline for low-rise confined masonry buildings

International Workshop "Reduction du risque sismique", Chlef (Algeria),, Oct 10, 2012

Seismic behavior of a heterogeneous soil with uncertain height

14th World Conference on Earthquake Engineering, 14WCEE, Oct 12, 2008

Integrated Risk Assessment Methods in Natural and Industrial Risks and Hazards

Collaborative Science and Technologue Workshop "Seismic Fragility and Urban Buildings and Infrastructure", London July 10-11, Jul 10, 2013

Impacts de fragments structuraux résultant d'explosions et vulnérabilité des installations industrielles

Technological (domino effect) and natural hazards: A probabilistic framework for structural vulnerability

2010 2nd International Conference on Reliability, Safety and Hazard - Risk-Based Technologies and Physics-of-Failure Methods (ICRESH), 2010

... and / or numerical behavior of these structures under impact) is still a large field of scien... more ... and / or numerical behavior of these structures under impact) is still a large field of scientificinvestigation, despite numerous ... General and simplified movement equations for the fragment centre are proposed in [11]. ... [9] Mebarki A. & Mercier F. (2010), Domino effect in industrial ...

The objective of this work is to develop an Intelligent Credit Card Fraud Detection System which ... more The objective of this work is to develop an Intelligent Credit Card Fraud Detection System which can detect and prevent online credit, card fraud. Hidden Markov Model was applied in determining the spending habit or profile of credit card holders. And with the spending profile established, it becomes possible to determine if an incoming transaction from a card holder is fraudulent or not by comparing any new transaction with the credit card holder's spending history. Any deviation from the actual spending habit is seen as a probable fraud and will be restricted while further verification is carried out. The methodology adopted for this work is Structured System Analysis and Design Methodology (SSADM) and the programming language used is PHP-MYSQL. The system developed can be used by any bank or financial institutions dealing on credit cards to detect and prevent all kinds of credit card fraud as it has been found to be capable of detecting such possible online fraud. 1.1 Background of the Study A secured and trusted inter-banking network for electronic commerce requires high speed verification and authentication mechanisms that allow legitimate users easy access to conduct their business, while thwarting fraudulent transaction attempts by others. Fraudulent electronic transactions are already a significant problem, one that will grow in importance as the number of access points in the nation's financial information system grows. (Stolfo et al., 1998). The popularity of on-line shopping is growing day by day. According to an AC Nielsen study conducted in 2005, one-tenth of the world's population is shopping on-line. In today's increasingly electronic society and with the rapid advances of electronic commerce on the Internet, the use of credit cards for purchases has become convenient and necessary.

Natural Hazards and Earth System Science, 2012

This paper deals with the failure risk of masonry constructions under the effect of floods. It is... more This paper deals with the failure risk of masonry constructions under the effect of floods. It is developed within a probabilistic framework, with loads and resistances considered as random variables. Two complementary approaches have been investigated for this purpose: -a global approach based on combined effects of several governing parameters with individual weighted contribution (material quality and geometry, presence and distance between columns, beams, openings, resistance of the soil and its slope. . . ), -and a reliability method using the failure mechanism of masonry walls standing out-plane pressure. The evolution of the probability of failure of masonry constructions according to the flood water level is analysed. The analysis of different failure probability scenarios for masonry walls is conducted to calibrate the influence of each "vulnerability governing parameter" in the global approach that is widely used in risk assessment at the urban or regional scale. The global methodology is implemented in a GIS that provides the spatial distribution of damage risk for different flood scenarios. A real case is considered for the simulations, i.e. Cheffes sur Sarthe (France), for which the observed river discharge, the hydraulic load according to the Digital Terrain Model, and the structural resistance are considered as random variables. The damage probability values provided by both approaches are compared. Discussions are also developed about reduction and mitigation of the flood disaster at various scales (set of structures, city, region) as well as resilience.

Structural fragments and explosions in industrial facilities: Part II – Projectile trajectory and probability of impact

Journal of Loss Prevention in the Process Industries, 2009

... Fig. 1. A generic sequence of domino effect: fragments generation, impact and interaction wit... more ... Fig. 1. A generic sequence of domino effect: fragments generation, impact and interaction with targets. View Within Article. ... A complete movement approach: The motion is calculatednumerically since the drag and lift coefficients vary during the motion. ...

Bulletin of Earthquake Engineering, 2014

Located at the NorthEastern part of Algeria (Tellian Atlas), Constantine has crucial administrati... more Located at the NorthEastern part of Algeria (Tellian Atlas), Constantine has crucial administrative, economic, scientific and cultural importance. It has continuously experienced significant urban evolutions during the different periods of its history. The city is located in an active seismic region within Algeria and has been struck in the past by several moderate and strong earthquakes. The strongest earthquake recorded since the beginning of instrumental seismology took place on October 27, 1985 with a magnitude M S = 5.9. Constantine presents a high seismic risk, because of its dense housing and high population density (2,374 inhabitants/km 2). This requires a risk assessment in order to take preventive measures and reduce the losses in case of potential major earthquake. For this purpose, a scenario based approach is considered. The building damage assessment methodology adopted for the Algerian context is adapted from HAZUS approach. In the present case, the effective Algerian seismic code response spectrum (RPA 99/2003) is considered as a seismic hazard model. The prediction of the expected damages is performed for a set of almost 29,000 buildings.

The behaviour of masonry walls subjected to fire: Modelling and parametrical studies in the case of hollow burnt-clay bricks

Fire Safety Journal, 2009

A thermo-mechanical model is adopted in order to investigate the fire behaviour of clay masonry w... more A thermo-mechanical model is adopted in order to investigate the fire behaviour of clay masonry walls. In this analysis, conductive, convective and radiative thermal transfers are considered together with local energy consumption due to phase changes. These latter ...

Electrification hazard of turbulent pipe flow: Theoretical approach and numerical simulation

Process Safety and Environmental Protection

Vulnérabilité de structures soumises à des explosions. Une protection qui pourrait être améliorée

Le projet Vulcain etudie la vulnerabilite mecanique de constructions (structures industrielles de... more Le projet Vulcain etudie la vulnerabilite mecanique de constructions (structures industrielles de stockage ou protection) soumises a des impacts ou explosions. Il a pour objectifs d'ameliorer la qualite des modeles physiques dans le cas de modelisations fines, de proposer des essais originaux et d'apporter un eclairage pour les pratiques d'ingenierie. Il contribue au developpement de modelisations fines de phenomenes complexes (impact sur du beton) ou plus pragmatiques, utilisables par l'ingenieur pour justifier une enceinte industrielle. La pratique francaise pour les sites Seveso peut conduire a des dimensionnements securitaires ou dangereux, car il ne prend pas en compte l'effet de l'impact des projectiles et suppose une surpression maximale deduite du retour d'experience. Des recherches en cours concernent les accidents industriels en chaine (effet domino, proposition d'indicateurs de vulnerabilite en termes de distance aux enceintes, de taille,de...

J. Inf. Technol. Constr., 2021

For any building project, the project management triangle QCT (Quality, Cost, Time) are decisive ... more For any building project, the project management triangle QCT (Quality, Cost, Time) are decisive in the decision-making process. Indeed, better, faster and cheaper remain very important goals in the design of new industrial products in a competitive environment. In this paper, we propose a reference framework to formalize the quality criterion that characterizes a building made during a project. A quality measurement is then defined based on the performance levels of the functions actually provided by a building and the requirements originally formulated by its owner. In addition, a modeling of the building production process is proposed to observe the effects of technical or managerial choices on the expected quality of a new or renovated building. Finally, a representation of the level of performance of each building technical attribute over its life cycle is proposed in order to represent the performance recovery allowed by a renovation operation as a resilience process. In the e...

Algeria is one of the countries that have experienced several strong to moderate earthquakes duri... more Algeria is one of the countries that have experienced several strong to moderate earthquakes during the last decades. The experience of these events showed that the elaboration of adequate intervention measures was done after the first in situ inspections, which may take long time to provide information and therefore decreases the chance to find survivors. This delay is due to the lack of different means to locate quickly, at the early hours, the affected areas and due also to the uncertain alarm level to be given. In order to enhance the rapid response and emergency operation, disaster mitigation measures can be done. The present work consists on a development of an integrated rapid earthquake loss assessment model. The main motivation through this development is the ability to estimate the probable seismic damage and their spatial distribution in an affected area by a potential earthquake, according to the existing building context in Algeria. This framework based on the Algerian ...

Applications of statistics and probability : civil engineering reliability and risk analysis : proceedings of the ICASP 7 Conference, Paris, France, 10-13 July 1995

ICASP-7 is concerned with applications of statistics and probability in all domains of civil engi... more ICASP-7 is concerned with applications of statistics and probability in all domains of civil engineering, structural engineering and material sciences. Organized every four years since 1971, ICASP-7 brings together scientists, researchers and engineers devoted to a better understanding of uncertainty in civil engineering. The proceedings include papers selected by the national and international scientific committees. Both applied and theoretical papers deal with a large variety of topics such as: Soil mechanics and geotechnical engineering, mechanics of materials, mechanics of structures, environmental engineering and natural hazards, modeling of naturally occurring, accidental and service loads in the applications fields; decision theory, optimization techniques and codes, reliability theory, random processes and geostatistical methods, inverse problems and identification in the theoretical field.

Ce projet vise a proposer une methode d'evaluation de la tenue de structures de type enceinte... more Ce projet vise a proposer une methode d'evaluation de la tenue de structures de type enceinte (stockage, protection) soumises a une explosion ou un impact de projectiles. L'enjeu est de produire des outils, permettant d'une part de modeliser le chargement induit, d'autre part de modeliser la reponse de l'enceinte (metallique ou en beton arme) afin d'evaluer son risque de defaillance (dysfonctionnement). Cela requiert la definition prealable des dommages et de leurs probabilites d'occurrence. A cet effet, un partenariat entre des acteurs industriels et universitaires est propose. Leurs competences complementaires sont presentees, en vue d'un choix concerte d'etudes experimentales et numeriques, puis d'actions de prevention et de protection plus sures et economiques.

Vulnerability of dwelling houses on clayey soils

The paper deals with the effect of the depth to bedrock randomness on the seismic response of an ... more The paper deals with the effect of the depth to bedrock randomness on the seismic response of an Algiers site in time and frequency domains. Stochastic soil profile seismic analysis is carried out via Monte Carlo simulations coupled to the stiffness matrix method. The soil height is assumed to be a random variable with a log-normal distribution. The stochastic behavior of extreme ground acceleration and its response spectrum, transfer function, fundamental frequency, maximum amplitude, short-and mid-period amplification factors are derived from 1000 samples, as a parametric study is performed accounting for the influence of the coefficient of variation of the depth to bedrock. As the study herein considers a SH wave propagation pattern (SH stands for shear horizontal), the accelerations under study correspond to the E-W and N-S horizontal directions. The seismic acceleration corresponds to the Boumerdes earthquake (Algeria, May 21, 2003, M w = 6.5). The probability density functions of the output parameters are derived using the maximum entropy principle, and compared to the log-normal distribution. The soil height heterogeneity causes an increase in the fundamental frequency of the soil profile, as well as a wider frequency content, in such a way that a larger number of structures are concerned by the resonance phenomenon.

This study uses interferometric SAR techniques to identify landslides and lands prone to landslid... more This study uses interferometric SAR techniques to identify landslides and lands prone to landslides, detect fringes and changes in areas struck by earthquakes. The pilot study investigates the Mila region (Algeria) which suffered significant landslides and structural damages (earthquake: Mw 5, 2020-08-07): the study checks ground deformations and tracks earthquake-induced landslides. DInSAR analysis shows normal interferograms, with atmospheric contribution, and slight fringes. However, it identifies many landslides, the most important (2.5 m displacement) being located in Kherba neighborhood, causing severe damages to dwellings. In addition, SAR images and optical images (Sentinel-2) confirm site investigations. Although in Grarem City, optical images could not detect any disorder, the DInSAR analysis detected some coherence decays and small fringes (3.94 Km 2 area). These unnoticed ground disorders were confirmed during fields inspection. Such results have key importance since they can serve as an alert to monitor the zone at the proper time. Furthermore, Displacement time series analysis of many interferograms (April 2015 to September 2020) using LiCSBAS were performed to investigate the pre-event conditions and precursors of the slopes instabilities., LiCSBAS detects a line-of-sight subsidence velocity of-110 mm/y in the back hillside of Kherba, and high displacement velocity at specific points in Grarem region. 1 Introduction Although it is still challenging to predict exactly where and when natural hazards (earthquakes, landslides, floods, etc.) might occur, the capacity to monitor and survey the zones prone to important landslides as well as the capacity to identify and locate those impacted by earthquakes are key issues in risks mitigation, reduction, preparedness and adaptation. Actually, since earthquakes and landslides might occur in many places worldwide, they might cause a huge number of victims, important socioeconomic , assets damages and losses. Their impact can be significantly reduced thanks to satellite imaging which allows prediction and early alerts of some landslide cases (Jacquemart and Tiampo, 2021). It is then worth detecting or predicting critical ground changes at specific places, either after a geotechnical disorder occurs due to landslides and earthquakes mainly, or before it is suddenly triggered (Bakon et al., 2014; Galve et al., 2015). Such challenges can be tackled by regular image processing oriented landslides areas monitoring, in the aftermath of earthquakes, by means of SAR interferometric methods and optical images, for instance. Actually, since InSAR (Interferometric Synthetic Aperture Radar) is an active sensor system that uses microwave signals to collect data backscattered from the earth's surface,

Earthquake Resistant Engineering Structures XI, Jul 5, 2017

This contribution focuses on the adaptation and application of RADIUS methodology (Risk Assessmen... more This contribution focuses on the adaptation and application of RADIUS methodology (Risk Assessment Tools for Diagnosis of Urban Areas Against Seismic Disaster) integrated with a Geographic Information System (GIS) to the Algerian context for the seismic vulnerability evaluation in urban areas potentially exposed to earthquakes. Within this framework, this application aims to perform a probable earthquake scenario in the urban centre of Constantine city, located at the NorthEast of Algeria, which will allow the buildings seismic damage estimation of this city. For that, an extensive inventory of almost 31,000 buildings was carried out. The simulation of the expected building seismic damage and the generated GIS damage maps provides a predictive evaluation of the damage that can occur due to a potential earthquake near to Constantine city.The theoretical forecasts are considered important for decision makers in order to reduce building vulnerability, to take adequate preventive measures and to develop suitable strategies for prevention and emergency management plans to reduce the losses. They can also help to identify the most damaged areas in the early moments following an earthquake to take the adequate emergency measures.