THE EFFECT OF GEOTECHNICAL PROPERTIES ON THE BEARING CAPACITY OF SELECTED SOILS IN AL - NAJAF GOVERNORATE-IRAQ

Study of the characteristics of the physical, chemical and engineering of the soil is considered as an important matter in the processes of engineering projects (such as highways, dams, bridges, etc..). Study was done at selected locations in the governorate of Al-Najaf by drilling three boreholes with 10m depth, for disturbed (DS) and undisturbed (US) samples, to determine soil characteristics, and the level of groundwater depth in the study area because of their effect on the design of foundations. The laboratory and field tests showed that the soil is clayey high plasticity (CH) in most of the study area, while the chemical analysis of the water in the boreholes has a high concentration of SO4 (1031-1037) mg/l and PH values range from (7.7-8.0). The number of blows in the standard penetration (SPT) test was between (58-86) blows. The depth of groundwater was (0.5-0.9) m in the boreholes. The bearing capacity using the dynamic method was (21.45?31.35) T /m? for all boreholes, while the bearing capacity using the static method for depths from (1-3) m ranged from (9.82-14.20) T /m?. The study concluded that this soil needs some engineering treatments before establishing the engineering structures.