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Abstract: For a long time, people have invested in flood-prone areas because of favorable geographic areas that facilitate economic growth, such as access to natural resources and food reproduction. This fact forces the inhabitants of the... more
Abstract: For a long time, people have invested in flood-prone areas because of favorable geographic areas that facilitate economic growth, such as access to natural resources and food reproduction. This fact forces the inhabitants of the city of Ghardaia to protect their valuable properties against floods and to reflect on a flash-flood mitigation policy known in this part of southern Algeria. The Algerian authorities have implemented a flood management strategy which allows the affected company to increase its resilience to this risk. Following the increase in the density of population, often associated with the improvement of the standard of living and consequently the increase of goods and allocated infrastructure; flood resilience is gaining momentum for this permanent risk. The damage caused by floods tends to become more and more frequent. This refers to the growing vulnerability linked to the change of society in its evolution following the interference between investment an...
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The paper describes the methodology proposed in the PERPETUATE Project (funded by the Seventh Framework Programme – Theme ENV.2009.3.2.1.1). The methodology proposed in PERPETUATE uses a displacement-based approach for the vulnerability... more
The paper describes the methodology proposed in the PERPETUATE Project (funded by the Seventh Framework Programme – Theme ENV.2009.3.2.1.1). The methodology proposed in PERPETUATE uses a displacement-based approach for the vulnerability evaluation and design of interventions. The use of safety verification in terms of displacement, rather than strength, orients to new strengthening techniques and helps in the comprehension of interaction between structural elements and unmovable artistic assets. The procedure is based on the following fundamental steps: definition of performance limit states, specific for the cultural heritage assets (considering both structural and artistic assets); evaluation of seismic hazard and soil-foundation interactions; construction knowledge (non-destructive testing, material parameters, structural identification); development of structural models for the seismic analysis of masonry structures and artistic assets and design of interventions; application an...
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Research Interests: Geology and Seismology
The aim of this paper is to investigate the effect of the building fundamental period of reinforced concrete buildings of (6, 9, and 12-storey), with different floor plans: Symmetric, mono-symmetric, and unsymmetric. These structures are... more
The aim of this paper is to investigate the effect of the building fundamental period of reinforced concrete buildings of (6, 9, and 12-storey), with different floor plans: Symmetric, mono-symmetric, and unsymmetric. These structures are erected at different epicentral distances. Using the Boumerdes, Algeria (2003) earthquake data, we focused primarily on the establishment of the deterministic formulation linking the base shear force to two parameters: The first one is the fundamental period that represents the numerical fingerprint of the structure, and the second one is the epicentral distance used to represent the impact of the earthquake on this force. In a second step, with a view to highlight the effect of uncertainty in these parameters on the analyzed response, these parameters are modeled as random variables with a log-normal distribution. The variability of the coefficients of variation of the chosen uncertain parameters, on the statistics on the seismic base shear force, ...
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The goal of the paper is to highlight the effect of the building design and epicentral distance on the storey lateral displacements, for several reinforced concrete buildings (6, 9 and 12 stories). These structures are subjected to... more
The goal of the paper is to highlight the effect of the building design and epicentral distance on the storey lateral displacements, for several reinforced concrete buildings (6, 9 and 12 stories). These structures are subjected to seismic accelerations from the Boumerdes earthquake (Algeria, May 21st, Mw = 6.8). Using the response spectrum method (modal spectral approach), the analysis is performed in both longitudinal and transverse directions. The building design is expressed through the fundamental period and epicentral distance is used to represent the earthquake effect variation on storey lateral displacements and interstory drift for the considered buildings.
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International audienc
Research Interests: Geography, Geology, Earthquake Engineering, Built Environment, Numerical Simulation, and 14 moreComputer Simulation, Mexico City, Hazard Mapping, Mathematical Model, Megacity, Ground Motion, Earthquake Prediction, Point of View, Complex Structure, Structural model, Urban Area, Site Effect, International Union of Geological Sciences, and Episodes
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Site response characteristics at seismic stations were investigated using horizontal-to-vertical (H/V) spectral ratios calculated from a seismic-motion dataset of the 2003 Boumerdes earthquake, and transfer functions were evaluated from... more
Site response characteristics at seismic stations were investigated using horizontal-to-vertical (H/V) spectral ratios calculated from a seismic-motion dataset of the 2003 Boumerdes earthquake, and transfer functions were evaluated from soil profile data. Although high peak ground acceleration (PGA) values were recorded at some sites, the nonlinear effect at these stations was not clear. The H/V spectral ratios calculated from weak and strong motion events did not show a clear difference in the predominant period and amplitudes, and the shapes of the H/V ratios were flat for some stations. These observations are characteristic of the presence of firm to hard layers under the stations; however, one station was located on Quaternary deposits showed a remarkable amplification at the predominant period and a high PGA value.
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Two of the several ways of creating political will are good governance and economic incentives. The Global Assessment Report on Disaster Risk Reduction for 2009 acknowledged the importance of good governance for sustained efforts in... more
Two of the several ways of creating political will are good governance and economic incentives. The Global Assessment Report on Disaster Risk Reduction for 2009 acknowledged the importance of good governance for sustained efforts in disaster risk reduction (UNISDR 2009: 19). It pointed out that, while Disaster Risk Reduction (DRR) can result in significant savings, and thus should be regarded as an investment, often it is perceived as a cost (see also Kelman and Poole 2006). Thus, the benefits of DRR action should be made clearer and ...
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Detailed analysis was conducted for the recorded mainshock across the country during the 21 May 2003 Boumerdes, Algeria earthquake. A remarkable difference has been recorded between neighbour stations. Since local site conditions have a... more
Detailed analysis was conducted for the recorded mainshock across the country during the 21 May 2003 Boumerdes, Algeria earthquake. A remarkable difference has been recorded between neighbour stations. Since local site conditions have a significant effect on the ground motions, and hence on the damage distribution caused by the earthquake, microtremor survey was conducted at several sites of seismic observation stations. In this study, a particular attention is paid to 4 seismic network stations located in the most affected area between Algiers and Boumerdes provinces. Using the microtremor records and the strong motion records from five stations, the effect of soil condition on seismic motion is investigated and the damage distribution caused by this event is explained. The results from this study show that in some stations, the recorded high PGA values were influenced by high-frequency contents. However, in other stations, soil amplification is considered to be responsible for hig...
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This paper presents a stochastic analysis of expressions linking the reinforced concrete (RC) buildings maximum displacements to their natural period and the epicentral distances. Where, low- and medium-rise reinforced concrete buildings,... more
This paper presents a stochastic analysis of expressions linking the reinforced concrete (RC) buildings maximum displacements to their natural period and the epicentral distances. Where, low- and medium-rise reinforced concrete buildings, are tested under the effect of records collected during the Boumerdes earthquake (Algeria, May 21st, 2003) at different epicentral distances. First, the expressions linking building maximum displacement and interstory drift to the building natural period and epicentral distance are derived. Then, using Monte Carlo simulation, the effect of the uncertainty of the chosen parameters on the confidence intervals of the lateral displacement and interstory drift statistics is studied, where the natural period and the epicentral distance are considered as random variables with a log-normal distribution. The findings denote that the derived expressions are less influenced by fundamental period uncertainty than the that of the epicentral distance. A good acc...
The goal of the paper is to highlight the effect of the building design and epicentral distance on the storey lateral displacements, for several reinforced concrete buildings (6, 9 and 12 stories). These structures are subjected to... more
The goal of the paper is to highlight the effect of the building design and epicentral distance on the storey lateral displacements, for several reinforced concrete buildings (6, 9 and 12 stories). These structures are subjected to seismic accelerations from the Boumerdes earthquake (Algeria, May 21, Mw = 6.8). Using the response spectrum method (modal spectral approach), the analysis is performed in both longitudinal and transverse directions. The building design is expressed through the fundamental period and epicentral distance is used to represent the earthquake effect variation on storey lateral displacements and interstory drift for the considered buildings. Keywords—Epicentral distance, interstory drift, lateral displacement, natural period, reinforced concrete buildings.
The aim of this paper is to investigate the effect of the building fundamental period of reinforced concrete buildings of (6, 9, and 12-storey), with different floor plans: Symmetric, monosymmetric, and unsymmetric. These structures are... more
The aim of this paper is to investigate the effect of the building fundamental period of reinforced concrete buildings of (6, 9, and 12-storey), with different floor plans: Symmetric, monosymmetric, and unsymmetric. These structures are erected at different epicentral distances. Using the Boumerdes, Algeria (2003) earthquake data, we focused primarily on the establishment of the deterministic formulation linking the base shear force to two parameters: The first one is the fundamental period that represents the numerical fingerprint of the structure, and the second one is the epicentral distance used to represent the impact of the earthquake on this force. In a second step, with a view to highlight the effect of uncertainty in these parameters on the analyzed response, these parameters are modeled as random variables with a log-normal distribution. The variability of the coefficients of variation of the chosen uncertain parameters, on the statistics on the seismic base shear force, s...
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This paper presents the different earthquake disaster prevention and post-disaster measures taken by the government of Algeria between 1980 and 1995. It details the measures taken at the country level as well as those involving the... more
This paper presents the different earthquake disaster prevention and post-disaster measures taken by the government of Algeria between 1980 and 1995. It details the measures taken at the country level as well as those involving the co-operation of international organizations. It discusses post-disaster measures including the relief of victims and the methodology of the assessment of the serviceability of damaged structures after the disaster, which represents one of the most important duty of the emergency staff, are also discussed. It examines the range of needed, possible and practical pre-disaster measures which the government of Algeria should undertake and actively encourage. This study briefly presents scientific and non-scientific Algerian organizations.
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This study highlights the major contributing factors to the observed damage distribution in the city of Boumerdès after the 2003 Algeria earthquake. The results of field investigations and statistical analyses show that a majority of the... more
This study highlights the major contributing factors to the observed damage distribution in the city of Boumerdès after the 2003 Algeria earthquake. The results of field investigations and statistical analyses show that a majority of the damaged buildings, mostly mid-rise reinforced concrete (RC) moment-frame systems, were located on steep slopes and small hilltops, along river valleys. The horizontal-to-vertical (H/V) ratios from free-field microtremor measurements at these sites did not show clear results. In contrast, buildings with the same structural characteristics located on flat ground did not suffer much damage, and clear peaks were observed from the H/V ratio curves. The amplification effects of topography have not been incorporated into the revised Algerian seismic code, but the results from this study show the importance of considering this factor when designing new buildings for earthquake resistance.
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Site response characteristics at seismic stations were investigated using horizontal-to-vertical (H/V) spectral ratios calculated from a seismic-motion dataset of the 2003 Boumerdes earthquake, and transfer functions were evaluated from... more
Site response characteristics at seismic stations were investigated using horizontal-to-vertical (H/V) spectral ratios calculated from a seismic-motion dataset of the 2003 Boumerdes earthquake, and transfer functions were evaluated from soil profile data. Although high peak ground acceleration (PGA) values were recorded at some sites, the nonlinear effect at these stations was not clear. The H/V spectral ratios calculated from weak and strong motion events did not show a clear difference in the predominant period and amplitudes, and the shapes of the H/V ratios were flat for some stations. These observations are characteristic of the presence of firm to hard layers under the stations; however, one station was located on Quaternary deposits showed a remarkable amplification at the predominant period and a high PGA value.
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The objective of this work is to present a expertise on flooding hazard analysis and how to reduce the risk. The analysis concerns the disaster induced by the flood on November 10/11, 2001 in the Bab El Oued district of the city of... more
The objective of this work is to present a expertise on flooding hazard analysis and how to reduce the risk. The analysis concerns the disaster induced by the flood on November 10/11, 2001 in the Bab El Oued district of the city of Algiers.The study begins by an expertise of damages in related with the urban environment and the history of the urban growth of the site. After this phase, the work is focalized on the identification of the existing correlations between the development of the town and its vulnerability. The final step consists to elaborate the interpretations on the interactions between the urban growth, the sewerage network and the vulnerability of the urban system.In conclusion, several recommendations are formulated permitting the mitigation of the risk in the future. The principal recommendations concern the new urban operations and the existing urbanized sites. Keywords—urban growth, sewerage network, vulnerability of town, flooding risk, mitigation
Dr. Benouar presents a full and integrated study of the recent seismicity of Algeria and adjacent regions during the twentieth century. He has amassed an impressive amount of macroseismic information pertaining to individual earthquakes,... more
Dr. Benouar presents a full and integrated study of the recent seismicity of Algeria and adjacent regions during the twentieth century. He has amassed an impressive amount of macroseismic information pertaining to individual earthquakes, which he combines with instrumental information to reassess the origin parameters of each event. In any compilation of earthquakes it is the additional information beyond the bare accumulation of figures and facts that adds interest and social understanding to the scientific appreciation of the earthquakes themselves. For this it is necessary to know the local conditions, and Dr. Benouar brings out for us very vivid1y the differences between reporting procedures at different times this century, and the ensuing difficulties. It would be most difficult for an outsider to gather the information he presents, and he makes good use of his knowledge of his native land, as well as his professional training as an engineer. We thus learn of the reluctance of ...
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Cited By (since 1996):2, Export Date: 1 December 2013, Source: Scopus
This work presents a contribution for a catalogue of the earthquake-resistant traditional techniques representing the urban, architectural and the structural aspects used in the Casbah of Algiers. These techniques were highlighted by a... more
This work presents a contribution for a catalogue of the earthquake-resistant traditional techniques representing the urban, architectural and the structural aspects used in the Casbah of Algiers. These techniques were highlighted by a detailed historical research in documentary sources (written and graphic sources, files, etc.) together with an archaeological investigation on the site and a comparison to the modern seismic
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... par Djillali BENOUAR Professeur, Directeur, Laboratoire de Recherche du Bâti dans l'Environnement (LBE) Faculté de Génie Civil USTHB, Alger, ALGERIE ... C'est une secousse soudaine et rapide de la terre provoquée par... more
... par Djillali BENOUAR Professeur, Directeur, Laboratoire de Recherche du Bâti dans l'Environnement (LBE) Faculté de Génie Civil USTHB, Alger, ALGERIE ... C'est une secousse soudaine et rapide de la terre provoquée par la libération de l'énergie stockée dans les roches. ...
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Research Interests: Geophysics and Seismology
Research Interests: Geophysics and Seismology
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... In Oran, at about 75 km north-west of Hacine, the main shock caused terror and general panic; some existing cracks in old buildings have ... of the weakness of constructions in the whole region to earthquake loads and even to rain,... more
... In Oran, at about 75 km north-west of Hacine, the main shock caused terror and general panic; some existing cracks in old buildings have ... of the weakness of constructions in the whole region to earthquake loads and even to rain, the degree of damage is an indication of the ...