Utilization of lime for stabilizing marl soils and investigating the effect of pH variations on shear strength parameters

In this paper، the effect of pH variations on shear strength parameters of lime stabilized soils was investigated. For this purpose marl soils collected from Ekbatan dam region of Hamedan were used. Collected soils were stabilized using lime، by adding different amount of limes (1%، 3%، 5% and 7%) and in different curing times (7، 15، 30 and 45 day). Based on test results conducted on these stabilized soils (uniaxial compressive test، consistency limits determining، compaction test) it was found that the optimum lime percent and curing time is to be 7% and 45 days respectively. In the second stage of this study، soil samples were prepared by optimum lime percent and curing time، then these samples were soaked in different pH solutions (pH=3، pH=5، pH=7 and pH=9) and their shear strength parameters (c، φ) were determined using direct shear test. Based on the results obtained from current study، it was found that by decreasing pH values of pore fluids، shear strength parameters of lime stabilized soils decreased.