In the water resources sector, the need to adopt a new way of thinking based on a systemic approa... more In the water resources sector, the need to adopt a new way of thinking based on a systemic approach and analysis is justified by several situations: very complex constraints that accompany the development of the sector, functional interactions between various planned developments and the multitude of actors and stakeholders involved. System engineering is a general methodological approach that encompasses all the appropriate activities to design, evolve and verify a system providing an economical and efficient solution to the needs of customers while satisfying the whole of stakeholders. Based on these concepts of size, the purpose of this paper is to apply the principles of systems engineering for the exploration and evaluation of Boughrara water resources system performance. This system located in the north-west of Algeria involves subsystems in constant interaction, namely mobilization, treatment, purification and transfer of water. Its performance takes into account a number of ...
Soil liquefaction is at the origin of major damage caused by an earthquake, both human lives lost... more Soil liquefaction is at the origin of major damage caused by an earthquake, both human lives lost as well as material losses. Several authors have studied soil liquefaction using deterministic and probabilistic methods. In this paper we study the effect of variation of the shear modulus on soil response defined by the excess pore pressure ratio (r u). Shear modulus is modeled by a log-normal random field, while discretization of the field is done using Karhunen Loève method. Finn deterministic model of liquefaction is modeled using the finite difference software Flac 3D. The results show that the spatial variation of soil properties has a significant impact on the excess pore pressure ratio.
Dispersive soils are characterized by an unstable structure, easily flocculated in water, and ver... more Dispersive soils are characterized by an unstable structure, easily flocculated in water, and very erodible (Zorluer et al., 2010). Using dispersive clay soils in hydraulic structures, embankment dams, or other structures such as roadway embankments can cause serious engineering problems if these soils are not identified and used appropriately. This .problem is worldwide, and structural failures attributed to dispersive soils have occurred in many countries. (Knodel, 1991). In our laboratories, only AFNOR tests it's used to identifying soils in road embankment and small hydraulic structures projects. However, there is simple method to identify the dispersivity of the soils and even more difficult to quantify the dispersivity. Visual classification, Atterberg's limits and particle size analysis do not provide sufficient basis to differentiate between dispersive clays and ordinary erosion resistant clays (Umesha and al., 2011).Dispersive clay identified by ASTM tests such as: ...
In this paper, transient responses of the Brezina concrete arch dam, located in the west of Alger... more In this paper, transient responses of the Brezina concrete arch dam, located in the west of Algeria, are determined using the finite elements commercial package, Ansys. A 3D model has been created to study the rock–fluid–structure interaction phenomenon. The foundation rock is modeled as a mass rock using solid finite elements, and the reservoir water is modeled using fluid finite element for the 3D model; the length and width of the foundation rock and water reservoir, along the global X and Y axes, are taken to be 150 m and 300 m, respectively, while its depth (or height), along the Z direction, is taken to be 100 m (the total height of the model is thus 160 m considering that the reservoir water height is taken to be 50 m). Coupling equations available in the Ansys code library are used to represent the dam–water and dam–foundation interfaces. It is found that the role of the reservoir water is mixed. In some cases, its presence is like a damper, which means it decreases the rang...
Etude de l'etat critique d'erosion interne des grands barrages (donnees du barrage de gra... more Etude de l'etat critique d'erosion interne des grands barrages (donnees du barrage de grand' maison) : percolation interne, resistance a l'erosion. Problemes de controle de l'homogeneite du noyau (materiau et compactage): application de l'analyse factorielle, optimisation du nombre d'essais de cisaillement par l'analyse de variance-covariance et l'estimation bayesienne ; possibilites de calcul de performance par elements finis stochastiques.
In this paper, modal responses of the Brezina concrete arch dam, Algeria, are determined using th... more In this paper, modal responses of the Brezina concrete arch dam, Algeria, are determined using the finite elements commercial packages ANSYS. To study the effects of the foundation soil, three 3D models have been created, the dam alone without soil, the dam-massless soil and the dam-soil with soil mass model. Moreover, a parametric study of the viscous damping, in Raleigh form, has been conducted. It is found that the natural frequencies of either undamped or damped modes obtained from the dam-soil with soil mass model are drastically lower compared to that of the dam alone model, and are markedly lower than those obtained from the dam-massless soil model. Likewise, similar comparisons have been observed for the damping quantities, in absolute values, between the three models. An in-depth review of the literature reveals that the study carried out herein constitutes several elements of originality as only very few similar work have been undertaken.
Pour les praticiens, comprendre le mecanisme fondamental qui provoque le gonflement des argiles e... more Pour les praticiens, comprendre le mecanisme fondamental qui provoque le gonflement des argiles est secondaire. Par contre, soupconner au prealable le caractere gonflant d'une formation et pouvoir ensuite obtenir rapidement des estimations de la pression et de l'amplitude de gonflement seraient d'un grand interet economique puisqu'elles permettent de mieux orienter les reconnaissances et informent les concepteurs sur le type de fondation a adopter. La recherche presentee dans cet article rentre dans le cadre de l'identification et de la prevision du comportement des sols gonflants. A cet effet, les classifications des sols gonflants disponibles dans la litterature sont passees en revue (et generalement utilisees pour l'identification des sols gonflants). L'application de ces classifications aux sols de la region de Tlemcen montre que ces dernieres respectent la tendance generale mais donnent parfois des appreciations contradictoires. Les modeles statistiq...
RESUME : L’argile est un sol d’assise pour un grand nombre de constructions. Certaines familles d... more RESUME : L’argile est un sol d’assise pour un grand nombre de constructions. Certaines familles d’argile presentent la caracteristique d’etre gonflantes ou retractables. Cependant, La construction sur ce type de sol necessite une bonne compagne de reconnaissance d’identification et de caracterisation de son potentiel gonflant. Dans ce travail la stabilisation par l’ajout de lait chaux est utilisee. Cette utilisation s’explique par le fait que cette technique est celle qui presente le maximum d’avantage, notamment en ce qui concerne le cout et les methodes d’executions. Dans cette communication nous sommes interesses par deux volets :
In the preliminary reconnaissance phase and once the swelling of soil is suspected, it is possibl... more In the preliminary reconnaissance phase and once the swelling of soil is suspected, it is possible to obtain an estimation of swelling parameters (amplitude and pressure) using numerous rheological models proposed in the literature. These models relate the parameters of swelling to the geotechnical parameters determined from mechanical tests. The analysis of the behavior of clays is conducted by numerical simulation tests of compression and swelling by using the oedometer. This analysis is conducted using the software CASTEM2000 team from CEA-France. This simulation allows-among others-to develop a predictive procedure for estimating the parameters of swelling by the use of constitutive equations of Cam-Clay and Alonso. It should be noted that different simulations are performed; those using oedometer tests by the Cam- Clay model, and Alonso and free swell tests by the Alonso model. The results of this work show that the compressibility has been correctly simulated by both models. T...
The aim of this paper is to estimate the maximum Peak Ground Acceleration (PGA) of the three comp... more The aim of this paper is to estimate the maximum Peak Ground Acceleration (PGA) of the three components (vertical, east-west and north-south) using the feed-forward artificial neural network method (ANN) with a conjugate gradient backpropagation rule for the training. The inputs are the magnitude, the focal depth, the epicentral distance, the thickness of the sedimentary layers below the site down to a shear wave velocity equal to 800 m/s and the corresponding resonant frequency, while the target result is the PGA. Data collected from the KiK-net seismic data base in Japan have been used. 1850 records at 102 sites are considered in the training phase, while 326 records are kept for the test phase. The obtained results show that PGA computed using the ANN method are close to those recorded. Finally, a simple example is presented in which 55 records are used to compare the ANN method with two Ground Motion Prediction Equations (GMPEs). This example demonstrates how the ANN works and s...
The determination of response spectrum of a seismic excitation recorded on a chosen site is neces... more The determination of response spectrum of a seismic excitation recorded on a chosen site is necessary in the structural dynamic design. The response spectrum can be obtained directly from recorded seismic data but this operation is expensive. The aim of this work is to avoid this problem where the acceleration response spectrum at the free face of a classified site is generated from that of reference by using the method of Artificial Neural Networks (ANN). The recorded spectrum value and corresponding period represent the inputs of the RNA, while the output is only the spectrum response value on the free field. The seismic data and the sites of the KIK-NET accelerograph network are used for the training and the validation of the neuronal model. The promising results obtained by this approach open a new research orientation on the use of the ANN in the field of soil dynamics and signal treatment, thus allowing the enrichment of the paraseismic codes into force.
In the water resources sector, the need to adopt a new way of thinking based on a systemic approa... more In the water resources sector, the need to adopt a new way of thinking based on a systemic approach and analysis is justified by several situations: very complex constraints that accompany the development of the sector, functional interactions between various planned developments and the multitude of actors and stakeholders involved. System engineering is a general methodological approach that encompasses all the appropriate activities to design, evolve and verify a system providing an economical and efficient solution to the needs of customers while satisfying the whole of stakeholders. Based on these concepts of size, the purpose of this paper is to apply the principles of systems engineering for the exploration and evaluation of Boughrara water resources system performance. This system located in the north-west of Algeria involves subsystems in constant interaction, namely mobilization, treatment, purification and transfer of water. Its performance takes into account a number of ...
Soil liquefaction is at the origin of major damage caused by an earthquake, both human lives lost... more Soil liquefaction is at the origin of major damage caused by an earthquake, both human lives lost as well as material losses. Several authors have studied soil liquefaction using deterministic and probabilistic methods. In this paper we study the effect of variation of the shear modulus on soil response defined by the excess pore pressure ratio (r u). Shear modulus is modeled by a log-normal random field, while discretization of the field is done using Karhunen Loève method. Finn deterministic model of liquefaction is modeled using the finite difference software Flac 3D. The results show that the spatial variation of soil properties has a significant impact on the excess pore pressure ratio.
Dispersive soils are characterized by an unstable structure, easily flocculated in water, and ver... more Dispersive soils are characterized by an unstable structure, easily flocculated in water, and very erodible (Zorluer et al., 2010). Using dispersive clay soils in hydraulic structures, embankment dams, or other structures such as roadway embankments can cause serious engineering problems if these soils are not identified and used appropriately. This .problem is worldwide, and structural failures attributed to dispersive soils have occurred in many countries. (Knodel, 1991). In our laboratories, only AFNOR tests it's used to identifying soils in road embankment and small hydraulic structures projects. However, there is simple method to identify the dispersivity of the soils and even more difficult to quantify the dispersivity. Visual classification, Atterberg's limits and particle size analysis do not provide sufficient basis to differentiate between dispersive clays and ordinary erosion resistant clays (Umesha and al., 2011).Dispersive clay identified by ASTM tests such as: ...
In this paper, transient responses of the Brezina concrete arch dam, located in the west of Alger... more In this paper, transient responses of the Brezina concrete arch dam, located in the west of Algeria, are determined using the finite elements commercial package, Ansys. A 3D model has been created to study the rock–fluid–structure interaction phenomenon. The foundation rock is modeled as a mass rock using solid finite elements, and the reservoir water is modeled using fluid finite element for the 3D model; the length and width of the foundation rock and water reservoir, along the global X and Y axes, are taken to be 150 m and 300 m, respectively, while its depth (or height), along the Z direction, is taken to be 100 m (the total height of the model is thus 160 m considering that the reservoir water height is taken to be 50 m). Coupling equations available in the Ansys code library are used to represent the dam–water and dam–foundation interfaces. It is found that the role of the reservoir water is mixed. In some cases, its presence is like a damper, which means it decreases the rang...
Etude de l'etat critique d'erosion interne des grands barrages (donnees du barrage de gra... more Etude de l'etat critique d'erosion interne des grands barrages (donnees du barrage de grand' maison) : percolation interne, resistance a l'erosion. Problemes de controle de l'homogeneite du noyau (materiau et compactage): application de l'analyse factorielle, optimisation du nombre d'essais de cisaillement par l'analyse de variance-covariance et l'estimation bayesienne ; possibilites de calcul de performance par elements finis stochastiques.
In this paper, modal responses of the Brezina concrete arch dam, Algeria, are determined using th... more In this paper, modal responses of the Brezina concrete arch dam, Algeria, are determined using the finite elements commercial packages ANSYS. To study the effects of the foundation soil, three 3D models have been created, the dam alone without soil, the dam-massless soil and the dam-soil with soil mass model. Moreover, a parametric study of the viscous damping, in Raleigh form, has been conducted. It is found that the natural frequencies of either undamped or damped modes obtained from the dam-soil with soil mass model are drastically lower compared to that of the dam alone model, and are markedly lower than those obtained from the dam-massless soil model. Likewise, similar comparisons have been observed for the damping quantities, in absolute values, between the three models. An in-depth review of the literature reveals that the study carried out herein constitutes several elements of originality as only very few similar work have been undertaken.
Pour les praticiens, comprendre le mecanisme fondamental qui provoque le gonflement des argiles e... more Pour les praticiens, comprendre le mecanisme fondamental qui provoque le gonflement des argiles est secondaire. Par contre, soupconner au prealable le caractere gonflant d'une formation et pouvoir ensuite obtenir rapidement des estimations de la pression et de l'amplitude de gonflement seraient d'un grand interet economique puisqu'elles permettent de mieux orienter les reconnaissances et informent les concepteurs sur le type de fondation a adopter. La recherche presentee dans cet article rentre dans le cadre de l'identification et de la prevision du comportement des sols gonflants. A cet effet, les classifications des sols gonflants disponibles dans la litterature sont passees en revue (et generalement utilisees pour l'identification des sols gonflants). L'application de ces classifications aux sols de la region de Tlemcen montre que ces dernieres respectent la tendance generale mais donnent parfois des appreciations contradictoires. Les modeles statistiq...
RESUME : L’argile est un sol d’assise pour un grand nombre de constructions. Certaines familles d... more RESUME : L’argile est un sol d’assise pour un grand nombre de constructions. Certaines familles d’argile presentent la caracteristique d’etre gonflantes ou retractables. Cependant, La construction sur ce type de sol necessite une bonne compagne de reconnaissance d’identification et de caracterisation de son potentiel gonflant. Dans ce travail la stabilisation par l’ajout de lait chaux est utilisee. Cette utilisation s’explique par le fait que cette technique est celle qui presente le maximum d’avantage, notamment en ce qui concerne le cout et les methodes d’executions. Dans cette communication nous sommes interesses par deux volets :
In the preliminary reconnaissance phase and once the swelling of soil is suspected, it is possibl... more In the preliminary reconnaissance phase and once the swelling of soil is suspected, it is possible to obtain an estimation of swelling parameters (amplitude and pressure) using numerous rheological models proposed in the literature. These models relate the parameters of swelling to the geotechnical parameters determined from mechanical tests. The analysis of the behavior of clays is conducted by numerical simulation tests of compression and swelling by using the oedometer. This analysis is conducted using the software CASTEM2000 team from CEA-France. This simulation allows-among others-to develop a predictive procedure for estimating the parameters of swelling by the use of constitutive equations of Cam-Clay and Alonso. It should be noted that different simulations are performed; those using oedometer tests by the Cam- Clay model, and Alonso and free swell tests by the Alonso model. The results of this work show that the compressibility has been correctly simulated by both models. T...
The aim of this paper is to estimate the maximum Peak Ground Acceleration (PGA) of the three comp... more The aim of this paper is to estimate the maximum Peak Ground Acceleration (PGA) of the three components (vertical, east-west and north-south) using the feed-forward artificial neural network method (ANN) with a conjugate gradient backpropagation rule for the training. The inputs are the magnitude, the focal depth, the epicentral distance, the thickness of the sedimentary layers below the site down to a shear wave velocity equal to 800 m/s and the corresponding resonant frequency, while the target result is the PGA. Data collected from the KiK-net seismic data base in Japan have been used. 1850 records at 102 sites are considered in the training phase, while 326 records are kept for the test phase. The obtained results show that PGA computed using the ANN method are close to those recorded. Finally, a simple example is presented in which 55 records are used to compare the ANN method with two Ground Motion Prediction Equations (GMPEs). This example demonstrates how the ANN works and s...
The determination of response spectrum of a seismic excitation recorded on a chosen site is neces... more The determination of response spectrum of a seismic excitation recorded on a chosen site is necessary in the structural dynamic design. The response spectrum can be obtained directly from recorded seismic data but this operation is expensive. The aim of this work is to avoid this problem where the acceleration response spectrum at the free face of a classified site is generated from that of reference by using the method of Artificial Neural Networks (ANN). The recorded spectrum value and corresponding period represent the inputs of the RNA, while the output is only the spectrum response value on the free field. The seismic data and the sites of the KIK-NET accelerograph network are used for the training and the validation of the neuronal model. The promising results obtained by this approach open a new research orientation on the use of the ANN in the field of soil dynamics and signal treatment, thus allowing the enrichment of the paraseismic codes into force.
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Papers by Abdelmalek Bekkouche