Effect Of Soil Geotechnical Properties On The Concrete Foundation Of Buildings

Abstract

This study has been conducted on the project site of a multi-storey car garage in the district of Al-Saray, which is in center of Al-Nasiriya city, center of Thi-Qar governorate in southern Iraq. Notably, the stability of construction materials and engineering structures for any engineering projects is affected by the geotechnical properties of the soil. In this paper, the geotechnical properties that were studied included: the physical, engineering and chemical properties of the soil such as particle size distribution, consistency limits, the number of blows in the standard penetration test,in addition to sulphatecontent, gypsum content, total soluble salts, and organic matter content.Soil was classified by using USDA textural triangle in addition to using texture plasticity system into two layers. Based on the values of the consistency limits, soil has low rate of compressibility and exhibits medium to high degree of expansion.As a result, the number of blows in the standard penetration testis between (13-36) blows. Therefore, the results of standard penetration test technique showed that the state of soil is very stiff from (1-7) m and then becomes dense downward. Then, by relying on the same technique, the allowable bearing capacity of the soil is (342-418) kPa for depths from (3-23) m for all boreholes.  The results of chemical tests showed that the soil contains proportions that exceeded the acceptable limits for each of sulphate, gypsum, total soluble salts, and organic matter content, which are considered to influence the compression and resistance of the soil. Some problems can be expected due to the results of physical properties of soil and from high proportion of sulphate and gypsum.