Geological and Engineering Study of Sand dunes in Babylon Governorate Middle of Iraq
Ahmed S. Al-Turaihi,
, Jaffar H. Al-Zubaydi,
Jwad K. Manii,
Babylon Governorate is located approximately in the center of Iraq, about 100 km away from the capital, Baghdad. Its area is 5,119 km2, which constitutes 2% of the total area of Iraq. It is dominated by a desert climate, which is characterized by a low amount of rainfall, ranging from 50 to 200 mm annually, and high temperatures in summer may reach 50 ° C, dominated by northwest winds. The engineering study of sand dune soils revealed that the grain size distribution of the sand reached 99%. The sand is of the type (Sp), which is sandy poorly graded according to USCS, the values of the bulk density of sand dune soils for the locations of the study area ranged between 1.287 - 1.376 g / cm3, where the minimum was 1.287 g / cm3 in the Bermana area (the third site), while the maximum was 1.376 g / cm3 in the Ramlet Rashid site (the first site) at a average of 1.3315 g/cm3. From the direct shear test, the values of internal friction angle (Ø) for sand dune soils for the study area sites ranged between 33-34, where the minimum was 33 in Ramlet Rashid site, while the maximum was 34 in the Albu Faris site. with a rate of 33.5. The convergence of the values of the internal friction angle (Ø) for the sand dunes reflects the environment of deposition and the nature of the geometric shape of the sand dunes. The values of the cohesion (C) for all sites are zero because the soil is SP without cohesion and clays. The petrographic study of sand dune soils revealed that quartz is the most light mineral found in all locations, followed by rock fragments, which include: sedimentary rocks (calcareous rocks, carbonates, chert, evaporites, and clay rock fragments), followed by feldspar (alkali and plagioclase feldspar), and igneous rock fragments. metamorphic rocks and mud-covered grains. As for its heavy minerals components, mostly opaque minerals, the chlorite group, the mica group, the amphibole group, the pyroxene group, zircon, termolite, garnet, rhyolite, staurolite, kainite, rutile, and other minerals by 1%. X-ray diffraction test revealed the presence of quartz, albite and calcite, and X-ray fluorescence tests showed the presence of silica (Si02) and lime (CaO).