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1.
This paper presents the results of triaxial tests conducted for the investigation of the influence of geotextile on both the stress–strain and volumetric change behavior of reinforced sands. Tests were carried out on loose sand. The experimental program includes drained compression tests on samples reinforced with different values of both geotextile layers (1 ≤ Ng ≤ 3) and confining pressure (\(\upsigma_{\text{c}}^{\prime }\)) varying from 50 to 200 kPa. Tests show that the contribution of geotextile is negligible until an axial strain threshold that range between 2.5% for a confining pressure of 50 kPa to lower than 1% for 100 and 200 kPa confining pressure. At higher values of εa, geotextile induces a quasi-linear increase in the stress deviator (q) and volume contraction in the reinforced sand. Tests show a negligible influence of the number of geotextile layers (Ng) on the contribution of geotextile to both stress–strain and volumetric change, when normalized with Ng. Tests also show that the contribution of geotextile to the stress–strain mobilization augments with the increase in the confining pressure, while its contribution to the volume contraction decreases with the increase in the confining pressure. The reinforced soil becomes contracting in the case of 2 and 3 geotextile layers.  相似文献   
2.
Geotechnical and Geological Engineering - This paper presents a study on Chlef sand to examine the effect of fines content (Fc), relative density (RD) and initial conditions on the compressibility...  相似文献   
3.
Geotechnical and Geological Engineering - 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...  相似文献   
4.
Landslides - This work aims to develop a Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) in-house code for modelling landslide–water interaction problems. While we consider the...  相似文献   
5.
Aurès region remains one of the most exposed areas to water erosion phenomenon in Algeria, because of the strong climatic aggressiveness, the rugged relief, the predominance of sensitive land, and a vegetative cover that does not play its protective role. This article is a part of studies performed to protect agricultural and water infrastructure in this region. The main objective of this study is the cartographic modeling of an erosion hazard at the Oued Chemoura watershed, representative of the Aurès. The modeling approach uses a geographic information system and incorporates the following six factors controlling erosion: slope, friability of substrate, erodibility of soils, land cover, rainfall erosivity, and support practices. Result shows a synthetic map of the soil erosion hazard which locates the most threatened areas and priorities for possible planning interventions. A statistical study on the relationship solid–liquid flow was developed. Measurements conducted at the station of Chemoura, over the period 1969–1994, were exploited for this purpose. The results show a high specific degradation varying between 50 and 360 tons km?2 season?1.  相似文献   
6.
Groundwater of the Tafilalet oasis system (TOS) is an important water resource in the lower Ziz and Rheris valleys of arid southeastern Morocco. The unconfined aquifer is exploited for domestic consumption and irrigation. A groundwater flow model was developed to assess the impact of climatic variations and development, including the construction of hydraulic structures, on the hydrodynamic behavior of the aquifer. Numerical simulations were performed by implementing a spatial database within a geographic information system and using the Arc Hydro Groundwater tool with the code MODFLOW-2000. The results of steady-state and transient simulations between 1960 and 2011 show that the water table is at equilibrium between recharge, which is mainly by surface-water infiltration, and discharge by evapotranspiration. After the commissioning of the Hassan Addakhil dam in 1971, hydraulic heads became more sensitive to annual variations than to seasonal variations. Heads are also influenced by recurrent droughts and the highest water-level changes are recorded in irrigated areas. The model provides a way of managing groundwater resources in the TOS. It can be used as a tool to predict the impact of different management plans for the protection of groundwater against overexploitation and deterioration of water quality.  相似文献   
7.
In the Saoura, the brachiopod shell beds, so-called niveau coralligène, correspond to a major shell deposit dated to the Late Emsian. Brachiopods and crinoids dominate the benthic assemblage that contains also corals, bryozoans, trilobites, goniatites, and orthocones. This major level has a large geographic distribution and it is characterized by a wide brachiopod diversity due to time-averaging, taphonomic feedback and alternate bottom conditions changing from soft to shelly and firm. This kind of brachiopod association is linked to a transgressive onlap system. At regional extent, we can correlate this major shell bed to similar shell deposits from the Ahnet-Mouydir, Tindouf, and Zemmour areas. It indicates an important transgressive event underlined by change in the sedimentation from detritic deposits to carbonate sediments. To cite this article: A. Ouali Mehadji et al., C. R. Geoscience 336 (2004).  相似文献   
8.
Optimal and sustainable extraction of groundwater in coastal aquifers   总被引:1,自引:0,他引:1  
Four examples are investigated for the optimal and sustainable extraction of groundwater from a coastal aquifer under the threat of seawater intrusion. The objectives and constraints of these management scenarios include maximizing the total volume of water pumped, maximizing the profit of selling water, minimizing the operational and water treatment costs, minimizing the salt concentration of the pumped water, and controlling the drawdown limits. The physical model is based on the density-dependent advective-dispersive solute transport model. Genetic algorithm is used as the optimization tool. The models are tested on a hypothetical confined aquifer with four pumping wells located at various depths. These solutions establish the feasibility of simulating various management scenarios under complex three-dimensional flow and transport processes in coastal aquifers for the optimal and sustainable use of groundwater.  相似文献   
9.
The groundwater hydrogeology of southern Tunisia emphasizes two main groundwater bodies so-called Zeuss-Koutine and south Gabes. These groundwater bodies yielding economically important storage of useful water present complex internal architecture and heterogeneity allowing exchange flows throughout permeable or/and fractured bodies. A geophysical survey using resistivity soundings was carried out along this area to describe in detail the field structure and the 3D extent of these groundwater bodies by the hydrogeological new data and detailed subsurface mapping based on resistivity sounding and seismic data. This survey discusses also the potentialities of some permeable layer in water storage and purposes potential favorable areas for optimum groundwater mining.  相似文献   
10.
The study focuses on the characterization of the groundwater salinity on the Nador coastal aquifer (Algeria). The groundwater quality has undergone serious deterioration due to overexploitation. Groundwater samplings were carried out in high and low waters in 2013, in order to study the evolution of groundwater hydrochemistry from the recharge to the coastal area. Different kinds of statistical analysis were made in order to identify the main hydrogeochemical processes occurring in the aquifer and to discriminate between different groups of groundwater. These statistical methods provide a better understanding of the aquifer hydrochem-istry, and put in evidence a hydrochemical classification of wells, showing that the area with higher salinity is located close to the coast, in the first two kilometers, where the salinity gradually increases as one approaches the seaside and suggests the groundwater salinization by sea-water intrusion.  相似文献   
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