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Remki M.,National Earthquake Engineering Research Center | Benouar D.,University of Science and Technology Houari Boumediene
KSCE Journal of Civil Engineering | Year: 2014

The estimation of losses resulting from an earthquake requires that for each building class, the relationship between the intensity of ground shaking and damage degree must be known or developed. Potential earthquake damage to structures, human beings and personal property have been the scope of numerous studies. Different approaches have been employed so far to estimate earthquake casualties and damage. This paper describe the basic concept for development of analytical vulnerability functions based essentially on so called damage model which was performed from probabilistic studies on seismic capacity of existing buildings in the city of Algiers (Algeria). Regarding the developed model for assessing the seismic damage, vulnerability functions of specific losses (potential losses for a specific urban area in terms of meter square area of building slabs which may involve causalities) were developed in order to predict the expected seismic risk for a given ground motion scenario. © 2014 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg.


Kehila F.,National Earthquake Engineering Research Center | Kehila F.,University of Science and Technology Houari Boumediene | Bechtoula H.,National Earthquake Engineering Research Center | Benaouar D.,University of Science and Technology Houari Boumediene
Computers and Concrete | Year: 2015

Piers are the most vulnerable part of a bridge structure during an earthquake event. During Kobe earthquake in 1995, several bridge piers of the Hanshin Expressway collapsed for more than 600m of the bridge length. In this paper, the most important results of an experimental and analytical investigation of ten reinforced concrete bridge piers specimens with the same cross section subjected to constant axial (or variable) load and reversed (or one direction) cycling loading are presented. The objective was to investigate the main parameters influencing the seismic performance of reinforced concrete bridge piers. It was found that loading history and axial load intensity had a great influence on the performance of piers, especially concerning strength and stiffness degradation as well as the energy dissipation. Controlling these parameters is one of the keys for an ideal seismic performance for a given structure during an eventual seismic event. Numerical models for the tested specimens were developed and analyzed using SeismoStruct software. The analytical results show reasonable agreement with the experimental ones. The analysis not only correctly predicted the stiffness, load, and deformation at the peak, but also captured the post-peak softening as well. The analytical results showed that, in all cases, the ratio, experimental peak strength to the analytical one, was greater than 0.95. Copyright © 2015 Techno-Press, Ltd.


Remki M.,National Earthquake Engineering Research Center | Kehila F.,National Earthquake Engineering Research Center | Bechtoula H.,National Earthquake Engineering Research Center | Bourzam A.,University of Science and Technology Houari Boumediene
Earthquake and Structures | Year: 2016

During the last decades, many destructive earthquakes occurred in Algeria, particularly in the northern part of the country (Chlef (1980), Constantine (1985), Tipaza (1989), Mascara (1994), Ain-Benian (1996), Ain Temouchent (1999), Beni Ourtilane (2000), and recently Boumerdés (2003), causing enormous losses in human lives, buildings and equipments. In order to reduce this risk and avoid serious damages to the strategic existing buildings, the authorities of the country, aware of this risk and in order to have the necessary elements that let them to know and estimate the potential losses in advance, with an acceptable error, and to take the necessary countermeasures, decided to invest into seismic upgrade, strengthening and retrofitting of those buildings. To do so, seismic vulnerability study of this category of buildings has been considered. Structural analysis is performed based on the site investigation (inspection of the building, collecting data, materials characteristics, general conditions of the building, etc.), and existing drawings (architectural plans, structural design, etc.). The aim of these seismic vulnerability studies is to develop guidelines and a methodology for rehabilitation of existing buildings. This paper presents the methodology, based on non linear and seismic analysis of existing buildings, followed in this study and summarizes the vulnerability assessment and strengthening of one of the strategic buildings according to the new Algerian code RPA 99/version 2003. As a direct application of this methodology, both, static equivalent method and non linear dynamic analysis, of composite concrete masonry existing building in the city of "CONSTANTINE", located in the east side of ALGERIA, are presented in this paper. © 2016 Techno-Press, Ltd.


Mehani Y.,National Earthquake Engineering Research Center | Benouar D.,University of Science and Technology Houari Boumediene | Bechtoula H.,National Earthquake Engineering Research Center | Kibboua A.,National Earthquake Engineering Research Center
Natural Hazards | Year: 2011

Algeria is a country with a high seismic activity. During the last decade, many destructive earthquakes occurred, particularly in the northern part, causing enormous losses in human lives, buildings, and equipments. In order to reduce this risk in the capital and avoid serious damages to the strategic existing buildings, the government decided to invest in seismic upgrade, strengthening, and retrofitting of these buildings. To do so, seismic vulnerability study of this category of buildings has been considered. Structural analysis is performed based on a site investigation (inspection of the building, collecting data, materials characteristics, general conditions of the building, etc.) and existing drawings (architectural plans, structural design, etc.). The aim of these seismic vulnerability studies is to develop guidelines and a methodology for rehabilitation of existing buildings. This paper presents the methodology followed in our study and summarizes the vulnerability assessment and strengthening of one of the strategic buildings according to the new Algerian Seismic Design Code RPA 99/version 2003. As a direct application of this methodology, both static equivalent method and nonlinear dynamic analysis are performed and presented in this paper. © 2011 Springer Science+Business Media B.V.


Chaouch A.A.,University of Science and Technology Houari Boumediene | Boutemeur R.,Polytechnic School of Algiers | Bechtoula H.,National Earthquake Engineering Research Center | Bali A.,Polytechnic School of Algiers
Periodica Polytechnica: Civil Engineering | Year: 2015

In recent years, and after the 2003 Boumerdes earthquake, a new type of building is being constructed in Algeria. The new concept is based on the concentration of reinforced concrete shear walls with L shape at the building corners. The seismic behavior of such configuration is not well known nowadays. Numerical investigation was carried out on reinforced concrete structure to evaluate the stress distribution at the base of the corner L shaped walls. Influence of number of stories, length of the shear wall as well as the thickness of the wall was considered in our investigation. In total, more than 200 numerical models were crated and analyzed. The analyses showed that, reinforced concrete wall with 15 cm, or less, in thickness should have a minimum length of 10 times the thickness; however, for RC walls with a thickness of more than 20 cm, the length of the wall should be greater than 7 times the thickness. In this paper the main results of this investigation are presented. © 2015, Technical University of Budapest. All rights reserved.


Kibboua A.,National Earthquake Engineering Research Center | Bechtoula H.,National Earthquake Engineering Research Center | Mehani Y.,National Earthquake Engineering Research Center | Naili M.,National Earthquake Engineering Research Center
Bulletin of Earthquake Engineering | Year: 2014

Algeria has an inheritance of more than 11,000 bridges, with approximately 5,000 road bridges of which more than 30 % have a high probability to be exposed to major earthquakes and serious damages in the future. Therefore, it is of great importance to retrofit the existing bridges and assess their seismic vulnerability and set a permanent monitoring survey to follow the change of their dynamic characteristics such as natural frequency and modal damping. The assessment of the seismic vulnerability of existing RC bridges was carried out based on the consistent and complete post earthquake survey after the Boumerdes earthquake. The information on the damaged existing RC bridges was investigated and evaluated by the authors. This paper presents a simple and efficient inspection method for the preliminary evaluation of the seismic vulnerability of existing bridge structures. To assess the seismic damage of 148 existing bridges, two seismic scenarios were carried out using "Khair al Din" and the "Zemmouri" faults that are capable to generate earthquakes with a maximum acceleration of 0.8g. The main findings of this study are summarized in this paper. © 2013 Springer Science+Business Media Dordrecht.


Remki M.,National Earthquake Engineering Research Center | Benouar D.,Sudan University of Science and Technology
Proceedings of the 8th International Conference on Structural Dynamics, EURODYN 2011 | Year: 2011

The estimation of losses resulting from an earthquake requires that for each building class, the relationship between the intensity of ground shaking and damage degree must be known or developed. Potential earthquake damage to structures, human beings and personal property have been the scope of numerous studies. Different approaches have been employed so far to estimate earthquake casualties and damage. This paper describe the basic concept for development of analytical vulnerability functions based essentially on so called damage model which was performed from probabilistic studies on seismic capacity of existing buildings in the city of Algiers. Regarding the developed model for assessing the seismic damage, vulnerability functions of specific losses were developed in order to define the expected seismic risk in case of particular ground motion.


Boukri M.,National Earthquake Engineering Research Center | Boukri M.,Blida University | Farsi M.N.,National Earthquake Engineering Research Center | Mebarki A.,University Paris Est Creteil | Belazougui M.,National Earthquake Engineering Research Center
Structural Engineering and Mechanics | Year: 2013

This paper presents a framework for seismic damage evaluation for Algerian buildings adapted from HAZUS approach (Hazard-United States). Capacity and fragility curves were adapted to fit the Algerian building typologies (Reinforced Concrete structures, Confined or Non-Confined Masonry, etc). For prediction purposes, it aims to estimate the damages and potential losses that may be generated by a given earthquake in a prone area or country. Its efficiency is validated by comparing the estimated and observed damages in Boumerdès city, in the aftermath of Boumerdès earthquake (Algeria: May 21st 2003; Mw = 6.8). For this purpose, observed damages reported for almost 3,700 buildings are compared to the theoretical predictions obtained under two distinct modelling of the seismic hazard. In one hand, the site response spectrum is built according to real accelerometric records obtained during the main shock. In the other hand, the effective Algerian seismic code response spectrum (RPA 99) in use by the time of the earthquake is considered; it required the prior fitting of Boumerdès site PGA (Peak Ground Acceleration) provided by Ambraseys' attenuation relationship. Copyright © 2013 Techno-Press, Ltd.


Chikh B.,National Earthquake Engineering Research Center | Mehani Y.,National Earthquake Engineering Research Center | Leblouba M.,University of Sharjah
Structural Engineering and Mechanics | Year: 2016

Methods for the seismic demands evaluation of structures require iterative procedures. Many studies dealt with the development of different inelastic spectra with the aim to simplify the evaluation of inelastic deformations and performance of structures. Recently, the concept of inelastic spectra has been adopted in the global scheme of the Performance-Based Seismic Design (PBSD) through Capacity Spectrum Method (CSM). For instance, the Modal Pushover Analysis (MPA) has been proved to provide accurate results for inelastic buildings to a similar degree of accuracy than the Response Spectrum Analysis (RSA) in estimating peak response for elastic buildings. In this paper, a simplified nonlinear procedure for evaluation of the seismic demand of structures is proposed with its applicability to multi-degree-of-freedom (MDOF) systems. The basic concept is to write the equation of motion of (MDOF) system into series of normal modes based on an inelastic modal decomposition in terms of ductility factor. The accuracy of the proposed procedure is verified against the Nonlinear Time History Analysis (NL-THA) results and Uncoupled Modal Response History Analysis (UMRHA) of a 9-story steel building subjected to El-Centro 1940 (N/S) as a first application. The comparison shows that the new theoretical approach is capable to provide accurate peak response with those obtained when using the NL-THA analysis. After that, a simplified nonlinear spectral analysis is proposed and illustrated by examples in order to describe inelastic response spectra and to relate it to the capacity curve (Pushover curve) by a new parameter of control, called normalized yield strength coefficient (η). In the second application, the proposed procedure is verified against the NL-THA analysis results of two buildings for 80 selected real ground motions. © 2016 Techno-Press, Ltd.


Boukri M.,National Earthquake Engineering Research Center | Boukri M.,Blida University | Farsi M.N.,National Earthquake Engineering Research Center | Mebarki A.,University Paris Est Creteil | Belazougui M.,National Earthquake Engineering Research Center
WIT Transactions on Information and Communication Technologies | Year: 2014

Algeria is one of the countries that have experienced several moderate to strong earthquakes during the last three decades causing considerable damage in the urban areas. This damage can be reduced if we proceed to estimate the seismic risk in sufficient time in order to take adequate preventive measures. In this paper, an earthquake damage assessment methodology, adapted from HAZUS approach (Hazard-United States) to the Algerian building context, which relies on the capacity spectrum method, is presented. It aims to estimate the damages and potential losses that may be generated by a given earthquake in a prone area. This methodology was calibrated and validated using the data of observed damages for ~3,700 buildings in Boumerdès city in the aftermath of the May 21st 2003 earthquake (Mw = 6.8). On the other hand, this methodology constitutes a decision-making tool for the concerned governmental organizations in charge to give the seismic warning with a level relative to the damage level, which can be estimated automatically by the data-processing code developed for this purpose, once the epicentre is localised and the magnitude known. © 2014 WIT Press.

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