The disorders caused by the swelling of the soil on the structures have been observed for several years in the city of Rufisque. This article presents the results of the study of swelling kinetics of expansive soils i...The disorders caused by the swelling of the soil on the structures have been observed for several years in the city of Rufisque. This article presents the results of the study of swelling kinetics of expansive soils in Rufisque and their prediction based on the hyperbolic rule. The odometer is used as an instrument for measuring swelling and the tests are carried out on some intact samples at their sampling water content. The present study shows that in Rufisque the most swelling layer is marl. The results show two phases of development. The first phase is very fast and represents 77% of the final deformation and the second one is slower. The prediction of the issue by the hyperbolic rule shows that it underestimates the first phase but gives a good prediction of the second phase of the swelling rate. There is a good correlation between the final swelling rates. However, the model gives a bad approximation of the half-swelling time.展开更多
Protective structures, built in the 1980＇s in order to reduce or stop coastal erosion in Rufisque, involved a modification of the coastal morpho-sedimentary landscape and have intensified the coastal dynamics. The di...Protective structures, built in the 1980＇s in order to reduce or stop coastal erosion in Rufisque, involved a modification of the coastal morpho-sedimentary landscape and have intensified the coastal dynamics. The diachronic study of beach profiles, before and after the seawalls construction showed that these protective structures accentuated the coastal erosion, with more important sedimentary deficits at the ends of the structures. Today, the Rufisque coast is characterized by a set of sedimentary cells whose morphological evolution and annual sedimentary dynamics are controlled by seasonal forcing： sedimentary deposits in dry season and erosion in wet season. However, this alternation of deposits and erosion phase shows spatiotemporal disparities. These disparities are very marked between a northwestern area characterized by concave profiles and a southeastern area （the bay of Rufisque） characterized by convex profiles and a much more important sedimentary deficit. The results also showed that these methods of shoreline protection are not durable measurements （degradation of the structures） and have exacerbated the vulnerability to coastal erosion as well as those of the coastal populations.展开更多
This study analysis was conducted to know the quality of well water around the market gardening area of Lendeng located in the common of Rufisque Est (Senegal). In this study, six groundwater samples were taken near t...This study analysis was conducted to know the quality of well water around the market gardening area of Lendeng located in the common of Rufisque Est (Senegal). In this study, six groundwater samples were taken near the Lendeng market gardening area. The physicochemical parameters of water such as pH, temperature, electrical conductivity (EC), calcium (Ca<sup>2+</sup>), magnesium (Mg<sup>2+</sup>), potassium (K<sup>+</sup>), iron (Fe<sup>2+</sup>), chloride (Cl<sup>-</sup>), sulfate (SO<sup>3-</sup>4</sub>) and phosphate (PO<sup>3-</sup>4</sub>) were measured. The analysis results obtained show sulphate and phosphate have the highest levels. These results were compared to drinking water standards from the World Health Organization (WHO). The correlation coefficient ANOVA was applied to the test result of the samples. The statistical study showed that the well water in the market gardening area of Lendeng is not polluted.展开更多
文摘The disorders caused by the swelling of the soil on the structures have been observed for several years in the city of Rufisque. This article presents the results of the study of swelling kinetics of expansive soils in Rufisque and their prediction based on the hyperbolic rule. The odometer is used as an instrument for measuring swelling and the tests are carried out on some intact samples at their sampling water content. The present study shows that in Rufisque the most swelling layer is marl. The results show two phases of development. The first phase is very fast and represents 77% of the final deformation and the second one is slower. The prediction of the issue by the hyperbolic rule shows that it underestimates the first phase but gives a good prediction of the second phase of the swelling rate. There is a good correlation between the final swelling rates. However, the model gives a bad approximation of the half-swelling time.
文摘Protective structures, built in the 1980＇s in order to reduce or stop coastal erosion in Rufisque, involved a modification of the coastal morpho-sedimentary landscape and have intensified the coastal dynamics. The diachronic study of beach profiles, before and after the seawalls construction showed that these protective structures accentuated the coastal erosion, with more important sedimentary deficits at the ends of the structures. Today, the Rufisque coast is characterized by a set of sedimentary cells whose morphological evolution and annual sedimentary dynamics are controlled by seasonal forcing： sedimentary deposits in dry season and erosion in wet season. However, this alternation of deposits and erosion phase shows spatiotemporal disparities. These disparities are very marked between a northwestern area characterized by concave profiles and a southeastern area （the bay of Rufisque） characterized by convex profiles and a much more important sedimentary deficit. The results also showed that these methods of shoreline protection are not durable measurements （degradation of the structures） and have exacerbated the vulnerability to coastal erosion as well as those of the coastal populations.
文摘This study analysis was conducted to know the quality of well water around the market gardening area of Lendeng located in the common of Rufisque Est (Senegal). In this study, six groundwater samples were taken near the Lendeng market gardening area. The physicochemical parameters of water such as pH, temperature, electrical conductivity (EC), calcium (Ca<sup>2+</sup>), magnesium (Mg<sup>2+</sup>), potassium (K<sup>+</sup>), iron (Fe<sup>2+</sup>), chloride (Cl<sup>-</sup>), sulfate (SO<sup>3-</sup>4</sub>) and phosphate (PO<sup>3-</sup>4</sub>) were measured. The analysis results obtained show sulphate and phosphate have the highest levels. These results were compared to drinking water standards from the World Health Organization (WHO). The correlation coefficient ANOVA was applied to the test result of the samples. The statistical study showed that the well water in the market gardening area of Lendeng is not polluted.
