Some mechanical properties of sandy gypseferous soils in Rumaila-Khor al-Zubair Area, Southern Iraq

Abstract EN

Six gypseferous soil samples were collected from Rumaila to Khor Al-Zubair areas, Didibba Desert west of Basrah city, Southern Iraq.

These soil are gypseous in nature with an average gypsum content of 15.

5 % W / w The mineralogical analyses revealed that they are consisting of quartz, gypsum, carbonate, and feldspar.

The grain size analysis showed that the sand fraction form more than 80 % of soil samples understudy.

Several geotechnical properties were determined.

The testing program comprises the determination of the effect of the different gypsum contents on the shear strength parameters ; cohesion and internal friction angle of the gypseferous soils under consideration.

Furthermore, the testing program exhibits the cohesion increases as gypsum contents increases up to 20 % then decreases at 30 %.

The results indicate that the improvement and deterioration of cohesion and shearing strength of soils are a result of the gypsum dual role, firstly bonding the soil particles, causing the and soil enhancement ( up to 20 % added gypsum), and secondly causing the flocculation of soil particles leading to the deterioration (More than 20 % added gypsum) of cohesion and shear strength of the gypseferous soils.