Seismic fragility curves are considered an effective tool for the evaluation of the behavior of interaction of the soil-pile-structure (ISPS) subjected to earthquake loading. In this research, in order to better understand the ISPS effect, a nonlinear static analysis is applied with a variation of the vertical load, the diameter of pile, and finally the longitudinal steel ratio of the pile in different types of sand (loose, medium, dense) to obtain the capacity curves of each parameter for elaborating the curves of fragility. After a comparison of fragility curves of these parameters, it appears that the effect of the ISPS system is advantageous with respect to the vertical axial load and the diameter of pile, while the longitudinal ratio of the pile depending on the ductility and the lateral resistance of the ISPS system. The proposed equation is intended to help engineers in the design and performance of the soil-pile-structure interaction. The results of this equation provided a convergence with the results of the fragility curves.
In this work, we study numerically the natural convection of NanoFluids (NF) in an inclined flat bottom flask; it is one of the laboratory flasks used in organic chemistry synthesis. The main reason for this study is to enhance the thermal properties of the reaction medium inside the flat bottom flask and to ameliorate the rate of chemical reactions using nanofluids. The flat bottom wall is maintained at a constant high-temperature Th. While the top, left and right walls of the cavity are maintained at a low-temperature TL. The NF comprises Cu and Al2O3 NanoParticles (NP) suspended in pure water. The governing equations are solved numerically using the finite-volume approach and formulated using the Boussinesq approximation. In this simulation we examined the effects of the NP volume fraction (φ) from 0% to 5%, the Rayleigh number from 103 to 106, the various inclination angles of enclosure (γ=0°,5°,10°, 15°) and the NF type (Cu and Al2O3) on the flow streamlines, isotherm distribution, and Nusselt number. The obtained results show that the addition of Cu and Al2O3 NP increases the mean Nusselt number which enhances the heat transfer in the flat bottom flask and causes significant changes in the flow pattern. In addition, the mean Nusselt number is increased with increasing the Rayleigh number and the volume fraction, and the best results have been obtained from the Cu nanofluid. Also, as the inclination angle increases the mean Nusselt number decreases, and the highest value of the Nusselt number was obtained for a vertical enclosure (γ=0°). The obtained streamlines are mostly symmetric and their values
are generally increased by increasing the Rayleigh number and volume fractions of NPs. Besides, the obtained isotherms generally follow the geometry of the flat bottom flask.
This research work is part of the trend of soil reinforcement procedures aimed at improving poor quality soils. Among these techniques, those that use stone columns. Although the aspects concerning the construction processes are now well mastered, the design methods of these reinforced soils remain to be developed. A numerical simulation presented to study two unit cell models. The 3D proposed simulation model is subjected to gravity and a static load. The first model presents a unit cell composed of stone column in the center and a surrounding clay soil volume. The second is converted into an equivalent unit cell (the volume averaging) in terms of physical and mechanical parameters of a composite material (equivalent parameters). Under the effect of incrementally loading–unloading applied to these unit cell models, voids ratio variations and stress path evolution are analyzed. The results indicate that applying a load to an equivalent unit cell can affect the void ratio-volumetric deformation curves and increase settlement. The void ratio and the corresponding volumetric deformation decreased by comparing the equivalent homogenized model with the non-homogenized model. The results show that the void ratio decreases by about 10% on average, but the volumetric strain decreases by 80%. Therefore, the stress path corresponding to the decrease of the average effective stress by 1% increases the deviatoric stress on average by 10%. Diagrams obtained by numerical results are in accordance with the results derived from experimental observations. The adopted technique can substantially can describe sufficiently the influence of the equivalents physical and mechanical parameters on the improvement in the soil of unit cell.
When designing tunnels, it is advisable to pre-estimate several tunnel parameters such as the depth (cover), the lining thickness, and the shape of the tunnel cross section. This condition is important in order to limit deformations during construction of the tunnel, and to ensure good tunnel resistance under seismic load conditions. In this context, the present paper is devoted to the analysis of the influence of some test parameters (the cover of the tunnel, the thickness of the lining, and the shape of the tunnel and the direction of the seismic waves) on the behaviour of the soil and the lining of a shallow tunnel built in soft ground subjected to seismic loading. The reference model for this parametric study is a real case, which happens to be the tunnel of Djebel El Ouahch (EastWest motorway) in the province of Constantine/ Algeria. The study is performed in three dimensions (3D) using a finite difference calculation method based on the FLAC3D calculation code. The results are presented in terms of shear strain induced in the soil around the tunnel, surface settlement, and vertical displacement of soil under the raft foundation, and also shear stress, bending moment, and shear strain, induced in the tunnel lining. The results show that the increase in thickness of the lining causes a reduction in shear force, and shear strain, while the circular or oval shape of the tunnel cross section results in low values of strain in the lining and ground displacement. It has been also pointed out that bending moment and shear strain induced in the lining are relatively low in comparison with the other forms. On the other hand, the direction of the seismic waves has a great influence on the behaviour of the lining and the surrounding soil. These results demonstrate that the strongest and most stable tunnel is the deepest tunnel with circular or oval section with a large thickness of the tunnel lining under the effect of compressive seismic waves. The results of the present study will be useful in the design of such a case by understanding the effects of various influencing parameters that control the stability of the tunnel in soil with bad characteristics
When designing tunnels, it is advisable to pre-estimate several tunnel parameters such as the depth (cover), the lining thickness, and the shape of the tunnel cross section. This condition is important in order to limit deformations during construction of the tunnel, and to ensure good tunnel resistance under seismic load conditions. In this context, the present paper is devoted to the analysis of the influence of some test parameters (the cover of the tunnel, the thickness of the lining, and the shape of the tunnel and the direction of the seismic waves) on the behaviour of the soil and the lining of a shallow tunnel built in soft ground subjected to seismic loading. The reference model for this parametric study is a real case, which happens to be the tunnel of Djebel El Ouahch (East-West motorway) in the province of Constantine/Algeria. The study is performed in three dimensions (3D) using a finite difference calculation method based on the FLAC3D calculation code. The results are presented in terms of shear strain induced in the soil around the tunnel, surface settlement, and vertical displacement of soil under the raft foundation, and also shear stress, bending moment, and shear strain, induced in the tunnel lining. The results show that the increase in thickness of the lining causes a reduction in shear force, and shear strain, while the circular or oval shape of the tunnel cross section results in low values of strain in the lining and ground displacement. It has been also pointed out that bending moment and shear strain induced in the lining are relatively low in comparison with the other forms. On the other hand, the direction of the seismic waves has a great influence on the behaviour of the lining and the surrounding soil. These results demonstrate that the strongest and most stable tunnel is the deepest tunnel with circular or oval section with a large thickness of the tunnel lining under the effect of compressive seismic waves. The results of the present study will be useful in the design of such a case by understanding the effects of various influencing parameters that control the stability of the tunnel in soil with bad characteristics.
Entre chasteté, décence, retenue et délicatesse, discrétion, réserve, la pudeur occupe un très vaste spectre d’attitudes et de sentiments. Tous de nature noble. Point de nuances amoindrissantes, ni de circonstances atténuantes et encore moins de considérations réductrices. De toutes parts, un faisceau d’appréciations très louables convergent vers la pudeur. Émanant même de ceux qui ne l’observent pas. Charles Baudelaire le comprenait bien qui écrivait : « Les hommes les moins pudiques aiment la pudeur dans l’objet aimé. » ... Cette quatrième parenthèse s'ouvrira sur toutes les formes de la pudeur.
Folie furieuse, folie douce, folie des grandeurs, la folie est partout dans la langue. Mais qu’est-ce que la folie ? Elle n'est pas pour la philosophie un objet de connaissance mais un obstacle à cet effort cognitif. Dans sa thèse, Michel Foucault s’empare de la pensée hégélienne et propose une analyse anthropologique de la folie. Insensiblement, la folie n’est plus une tare mais une fenêtre sur la vérité de l’homme...
Le colloque Grain de folie invite tous les chercheurs à apporter leur « grain de sel » sur cette question pluridisciplinaire...
The Mexa and Bougous dams were built to control river floods and supply crop-irrigation and drinking water. This study aimed to characterize the hydrogeochemical state in the region containing the dams, which influences the quality of the waters and thus their suitability for agricultural use, given the extent of the river networks that naturally transport sediments and pollutants into the reservoirs via streams. Thus, some physicochemical and organic parameters, including electrical conductivity, calcium, magnesium, sodium, potassium, chloride, bicarbonate, sulfate, biological oxygen demand, nitrite, ammonium, and phosphate, were used as benchmarks to examine the stiffness of the water pollution. Sampling was carried out during May and September of 2011 and 2012. The obtained results showed that, according to the Stiff diagram, the dominant hydrogeochemical facies is calcium bicarbonate in waters that do not have calcium levels in excess of 3 meq/l and bicarbonate levels in excess of 2.4 meq/l. The organic pollution index disclosed that the waters have evolved from a moderate to a high degree of organic pollution due to the accumulation of pollutants and nutrients from waste disposal and fertilizers. The samples fell into the C2-S1 class in the Richards diagram; this implies that the waters are suitable for plants that are salt tolerant, but that the use of these waters can cause problems for clay soils. However, in the long term, irrigation with the dam waters may pose difficulties for agriculture due to the resulting increase in the electrical conductivity of the soil. This study concludes that water salinity and alkalinity affect crop suitability, meaning that the temporal monitoring of water quality is needed to avoid adverse consequences for crop production.
Faisant partie intégrante du métier d’enseignant, l’évaluation constitue un acte pédagogique essentiel dans les situations d’enseignement-apprentissage et cela afin de vérifier le niveau linguistique des étudiants lors d’une acquisition réelle dans le but de lancer une formation ou bien clôturer une formation en prenant en compte ses difficultés. Pour notre étude, il s’agit d’une classe de langue étrangère réservée à un public adulte formé d’étudiants de filières différentes, souvent arabisées totalement ou partiellement, et que ce type d’enseignement doit les préparer soit à améliorer leur niveau général soit à leur dispenser un enseignement leur permettant de suivre une spécialisation en Algérie (enseignements en français) ou à l’étranger, notamment en France.
In this study, we investigate a production planning problem in hybrid manufacturing remanufacturing production system. The objective is the determine the best mix between the manufacturing of new products, and the remanufacturing of recovered products, based on economic and environmental considerations. It consists to determine the best manufacturing and remanufacturing plans to minimising the total economic cost (start-up and production costs of new and remanufactured products, storage costs of new and returned products and disposal costs) and the carbon emissions (new products, remanufactured products and disposed products). The hybrid system consists of a set of machines used to produce new products and remanufactured products of different grades (qualities). We assume that remanufacturing is more environmentally efficient, because it allows to reduce the disposal of used products. A multi-objective mathematical model is developed, and a non dominated sorting genetic algorithm (NSGA-II) based approach is proposed. Numerical experience is presented to study the impact of carbon emissions generated by new, remanufactured and disposed products, over a production horizon of several periods.
In this study, we investigate a production planning problem in hybrid manufacturing remanufacturing production system. The objective is the determine the best mix between the manufacturing of new products, and the remanufacturing of recovered products, based on economic and environmental considerations. It consists to determine the best manufacturing and remanufacturing plans to minimising the total economic cost (start-up and production costs of new and remanufactured products, storage costs of new and returned products and disposal costs) and the carbon emissions (new products, remanufactured products and disposed products). The hybrid system consists of a set of machines used to produce new products and remanufactured products of different grades (qualities). We assume that remanufacturing is more environmentally efficient, because it allows to reduce the disposal of used products. A multi-objective mathematical model is developed, and a non dominated sorting genetic algorithm (NSGA-II) based approach is proposed. Numerical experience is presented to study the impact of carbon emissions generated by new, remanufactured and disposed products, over a production horizon of several periods.
