Evaluation of Dynamic Properties of a Calcite Cemented Gravely Sand

Understanding of the effect of cementation on dynamic behaviour of cemented soil in an earthquake prone area could be crucial for earthquake resistance design. The major section of the city of Tehran has been developed on cemented coarse-grained alluvium. In order to understand the dynamic behaviour of this soil, a series of undrained cyclic triaxial tests were performed on uncemented and artificially calcite-cemented samples. In this paper, two dynamic parameters including dynamic shear modulus and damping ratio based on different definitions are investigated. In this regard the effects of cement content, confining pressure and cyclic deviatoric stress were studied as well. In general by increase in the amount of cementation, maximum shear modulus increases and damping ratio show no significant variation. Also, increase in deviatoric strain results in the increase in damping ratio and decrease in shear modulus. In addition the higher confining pressures lead to higher shear modulus and lower damping ratio. Furthermore the shear modulus decreases with increase in number of cycles.