Experimental Evaluation of Dynamic Characteristics of Firouzkooh Sand Using Cyclic Triaxial and Bender Element Tests

The main focus of this research is to obtain the dynamic properties of Firouzkooh sand and to study the effect of different factors, including specimen fabric, relative density, and consolidation anisotropy on those parameters. Dynamic properties, including shear modulus and damping ratio, play a significant role in predicting the dynamic response of soil. Having a correct estimate of those parameters in a wide strain range is essential for laboratory research and modeling. Thus, a laboratory testing program comprising of 116 experiments, including bender element and cyclic triaxial tests, was defined to obtain these properties in the strain range of 10(-6) up to 10(-2). During these tests, effective stress was in the range of 20-500 kPa and the relative density was between 16 and 74.2%. To study the effect of the type of specimen fabric, the sample preparation method was either dry deposition or wet tamping. At the same time, some tests were conducted with anisotropic consolidation. Results are presented in forms of shear modulus and damping ratio in relation to shear strain. Many of the previous studies conducted on different types of sands show consistent results. Additionally, a versatile preliminary empirical model, based on the previously proposed methods, is suggested to predict shear modulus and damping ratio curves of Firouzkooh sand, taking into account the sample fabric and consolidation method.