Study the Geotechnical Properties for Recent Deposits/AL-Fursan Area North of Tikrit

Abstract

Four sites with different depth in AL-Fursan area/ North Tikrit city were selected for recent deposits sampling. The geotechnical properties of soil were tested and improvement of engineering properties of soil by cement was carried out. The geotechnical properties test results revealed that the moisture content ranges between (0.53 -1.45)% which is low because of sampling in summer season, while the grain size analysis show that the soil at the study area is coarse soil (sand) with fines. The soil type in the first site is clayey sand (SC), the second site contains sand with equal percentage of silt and clay (SC- SM) , the third and fourth site types are silty sand (SM). The specific gravity ranges between (2.46- 2.72) sites (1,2,3) are low liquid limit and low swelling index but the fourth site is moderate. The value of cohesion strength for the four sites are (16, 13, 1, 8)kPa respectively, sites (1) and (2) are moderate cohesion while sites (3) and (4) are non-cohesion, none plastic and un active.
 The low values of cohesion strength belongs to high percentage of coarse particles in the area. The values of internal friction angles ranges between (300- 370). The consolidation test results revealed that all sites were moderate compressive index except the first site which is low compressive and low swelling. The study area soil are neutral and high content of gypsum and soluble Dissolved salts and also high organic content. The soil improvement by cement tests results show increasing of cohesion and internal friction angle and the compaction test results show the samples are well sorted.