A Theoretical Study of Some Unsaturated Properties for Different Soils

Abstract

Soil–water characteristic curves (SWCC) can be defined as the relationship between the water content and suction of an unsaturated soil. It considered a basic relation to explanation of the engineering behaviour of unsaturated soil such as hydraulic conductivity and shear strength, So the study of SWCC is useful to reduce the time and cost of unsaturated soil testing for different engineering purposes. An approach model has been used to predict the SWCC for different soils. The influence of the soils on SWCC shape, the unsaturated hydraulic conductivity and shear strength parameters have been studied in this paper using mathematical models. The results of SWCC show that suction of clay soil is bigger than sandy soil, while the clayey silt soils exhibit an intermediate behaviour at same water content. The values of unsaturated shear strength are increasing while the unsaturated hydraulic conductivity is decreasing with increasing soil suction. This behaviour of the last two parameters with soil suction should be taken in consideration for engineering purposes.

The Effect of Adding Organic Matter on the Efficiency of Salts Leaching in the Soil Affected by Salinity

“…Increasing the leaching stages led to a significant decrease in the concentration of dissolved sodium in the soil solution, as its rates reached 55.31, 46.06, 13.5, 12.94 and 11.94 mmol l -1 for the five stages, respectively, with a decrease of 16.72, 75.59, 76.60 and 78.41 %, respectively. It is also noted from the results that the values of dissolved sodium concentrations in the soil solution are lower at the end of the experiment (the fifth leaching stage) compared to the first leaching stage, which may be attributed to the fact that the intermittent leaching process is sufficient to leached the salts and prevent their accumulation at the end of the leaching, in addition to the low water conductivity rate of the soil in a way It increases with time, then slows down until the end of the leaching process [30].…”

Sustainable solar energy development in Zakho, Iraq: a techno-economic and environmental assessment

“…Summers are hot and dry, reaching 40.4℃ in July, while winters are moderate at 1.9℃ in January. The westward wind at 5.2 km/h and 44.9% humidity provide balance [27]. In Zakho, the Global Solar Radiation levels peak during June and July, registering the highest monthly averages, while December and January recorded the lowest values.…”