EFFECT OF ORGANIC CONTENT ON THE ENGINEERING PROPERTIES OF JORDANIAN CLAYEY SOILS

This research aims at determining the influence of mixing an organic material with a fine grained soil, on the physical and mechanical properties for the resulted mix using various percentages of organic matter, and then to compare the obtained results with those related to original soil (natural material without mixing), and consequently to draw different relationships that clarify a comparison between the results, and to indicate the extent of the effect of the mixing process on the behavior of the resulted soil. To achieve the above objectives, an artificial organic material (Pitmos) was prepared and mixed with clayey soil samples (collected from a construction site in Amman), and then several laboratory tests (including Atterberg limits, permeability and unconfined compression) had been conducted for the above investigation. Out of the results of this research, it was concluded that the existence of organic materials in a soil (especially in fine grained soils) may increase the soil's ability to show considerable volumetric changes, increase its permeability, and decrease its shear strength. And as a summary, it is not recommended to carry out foundations on fine grained soils that contain more than 2% organic matter.