Effect of compaction test component on development of stress-strain in the clay soil in comparison with sandy-clay soil

Soil strength and elasticity modules are important parameters in the engineering characteristics of soils. Bearing capacity is increased by soil strength. Elasticity module determines the potential of soil deformation. In this experiment، stabilization of problematic clay soils using sands were investigated. The samples were prepared with variable soil moisture and compaction، and were tested in single-axis compression apparatus in the soil mechanics laboratory of Shahid Chamran University (SCU) in Khuzistan province. The samples were tested with soil moistures as follows: optimum humidity; 2% and 4% less than optimum; and 2% and 4% more than optimum moisture. The compaction of applied، R. C، were equal to 85، 95 and 100 percents. Using the obtained data، the soil strength and elasticity modules were calculated. Our findings show that for all in clay and sandy-clay samples tested increasing moisture lead to decrease of soil strength. However، reduction of soil strength in the sandyclay sample is more than problematic clay soils samples. Results of these experiments regarding the moisture change from 4% less than optimum to 4% more than optimum، decreased soil strength of problematic clay soil، approximate 84%، while، for sandy-clay soil it was about 93 percents. Moreover، decreasing of elasticity module in sandy clay samples with 100% compaction and 13% moisture is approximately 51 percents.