Assessment of the Geotechnical Properties of Quaternary Deposits in Wadi- Al- Jafer, North of Salah Al- Din Governorate.
Abstract
The research aims to study some geotechnical properties of the Quaternary deposits in wadi- Al- Jafer south of Sharqat district, Salah- Al- Din Governorate to indicate their validity for some engineering purposes like foundation for earth fill dam.The geotechnical tests are carried out for seven representative samples of the sediments. The geotechnical tests show that the sediments contain varying sizes. Therefore, they are heterogeneous soil. classified through the plasticity chart as a clayey soil with low plasticity (CL) in some samples, while in most samples, the soil is silty soil with low plasticity (ML). The specific gravity and water content values range between (2.64 and 2.73) (1.10 and 8.33) % respectively. The chemical analyses show that the values of gypsum ratio, total dissolved salts (TDS), organic material ratio and sulphate ratio range between (7.31and 38.21) %, (11.84 and 41.16) %, (0.03and 0.35) % and (1.38 and 6.18) respectively. The pH values range between (7.91 and 7.98). These high percentages affect the engineering properties of soil. Through mechanical tests, it is found that the cohesion values range between (1.7 and 13.3) kg/ cm2. Cohesion values increase as the percentage of fine materials increases and decrease as the moisture content and coarse materials increase. The values of the internal friction angle range between (21 and 40) and affected by values of plasticity index and the increase in the percentage of coarse materials. Compression index (Cc) values range between (0.12 and 0.81), these differences in values reflect that the samples deposits have different compressibility. The values of the swelling index range between (0.014 and 0.097). This difference in values reflects that the sample deposits have different swelling ratio. Thus, we conclude that the deposits of the study area in general can be used for some engineering purposes after being treated as foundation for earth fill dams.
