The geophysical method (Cross-Hole Survey) was used to assess the bearing capacity of the soil in the study area to build a water treatment plant. It was noted, that the velocities of the primary and secondary waves decrease at the depths of 4 and 5 meters compared to the depths above and down, so, the lithology or physical properties of this specific soil have changed. It was also observed that seismic wave velocities are low in general due to the medium density and hardness of the soils in the study area. Furthermore, the elasticity modulus values were shown to decrease at depths of 4 and 5 meters. It is further evidence of the soil's weakness at these depths. When the type of layer changed, the elastic modulus changed as well. The geotechnical properties between the wells were evaluated based on the velocities of seismic waves (S-waves and P-waves) for classifying the load capacity values with the stiffness. The bearing capability of the soil was found to be medium-stiff at depths of 2 and 3 meters, but soft at depths of 4 and 5 meters. At depths of 6, 7, 8, 9, and 10 meters, the bearing capacity is stiff to very stiff.

Detecting the weathering zone is one of the required data correction steps to process reflection seismic data collected at the Majnoon oil field, south of Iraq. Two subsurface layers represent the weathering zone in this field. Those two layers were inferred by primary seismic waves utilizing the down-hole seismic method. Five wells in the studied area were drilled and named DH-1, DH-2, DH-3, DH-4 and DH-5. The collected seismic data was analyzed to determine the depths, thicknesses and lithology of the subsurface layers. The primary seismic wave velocities were calculated and applied to eliminate two sub-surface layers. The average primary wave velocities and thicknesses of the first layer were 374, 240, 211, 277, 370 m/s, and 2.8, 2, 2, 2, 4.9 m, respectively. In the second layer, the primary waves velocities were 1125, 1284, 1201, 1395 and 1008 m/s, and the thicknesses were 13.2, 11, 13, 11.5, 21.4 m. The first weathered layer represented on the five wells is clay. The second layer has different geometry on different wells, which is represented by a sandy clay layer on DH-1, and muddy clay on DH-2. Then, it is changed to be a silt layer in DH-3, sandy clay in DH-4 and DH-5.