Geophysical-Engineering study in landfill site Al-Kifil District-Babylon Governorate Middle of Iraq

Abstract

          Four seismic refraction profiles for both compressional (P) and shear (S) waves had been surveyed within AlKifil District/Babylon Governorate, Middle of Iraq, by the use of three impacts; normal, center and reverse shootings. In addition, cross-hole, down-hole and up-hole seismic refraction using couple boreholes were also conducted in the investigated site. These two techniques were done in order to delineate depths and thicknesses of the layers (soils), their dynamic elastic modulus and groundwater level underlying such establishment building may use for future landfill purposes.

          The calculations demonstrate that there are two shallow subsurface layers were found. The average of velocities and thicknesses of the first layer (consists of grayish silty sandy clay soil) are equal to 259.33, 147.83 m/sec and 6.58 m, and for the second one (consists of brownish and greenish silty clay soil with sand) are 517, 273.25 m/sec for each P and S-waves respectively. On the other hand, mean water table seems between 1.40 and 1.20 meters during Sep. 2012 and Sep. 2015 respectively. Moreover, the mean dynamic elastic constants were ranged between {?= (69.51-605.16) Mpa, ?= (24.64-212.37) Mpa, E= (60.40-510.93) Mpa, ?= (41.85-392.22) Mpa, and, ?= (0.18-0.37)}.

          Site engineering information including physical and geotechnical properties were also measured and analyzed to enhance the main targets of this study. Standard penetration test and bearing capacity values were performed and calculated for the studied soils. The average of the N-values in situ is equal to (11) impacts having bearing capacity (6.10) ton/m2 at (1.5) m depth interval. It noticed that the N-value is low near the ground surface because of the saturated clay existence (medium consistency). At depth intervals between (13-15)m, the N-value was reached (43) impacts and more; this indicates that the soil is cohesion and contains high percent of sand and low clays; therefore, all depth intervals or layers in the drilling wells are considered hard media and they have bearing capacity equals to (16) ton/m2. This means that the layers corresponding to these intervals were characterized by its hardness