TY - JOUR ID - 21521 TI - Effects of initial suction and degree of saturation on dynamic properties of sand at large strain JO - Scientia Iranica JA - SCI LA - en SN - 1026-3098 AU - Jafarzadeh, F. AU - Ahmadinezhad, A. AU - Sadeghi, H. AD - Department of Civil Engineering, Sharif University of Technology, Tehran, Iran. Y1 - 2021 PY - 2021 VL - 28 IS - 1 SP - 156 EP - 174 KW - Cyclic Simple Shear KW - Suction KW - Degree of saturation KW - shear modulus KW - damping ratio KW - Unsaturated Sand DO - 10.24200/sci.2019.51796.2452 N2 - Soil deposits may experience different hydraulic states in terms of suction (ψ) and degree of saturation (Sr) while subjected to large strain caused by dynamic loading during earthquakes. This phenomenon is investigated by considering the effects of initial ψ, initial Sr, sample preparation method, drainage condition, and cycle number (N) on dynamic properties. Shear modulus (G) and damping ratio (D) are specifically studied for an unsaturated sand using a modified cyclic simple shear device for all zones of soil water retention curve (SWRC). Results revealed the relative significance of both ψ and Sr in relation to SWRC on observed trends in G and D. Through analyzing some results from the literature, it was shown that most of the data follow a sigmoid function in the plane of normalized stiffness (G/Gsat) versus suction normalized to the air entry value. It was also revealed that minimum damping is not in conjugation with maximum stiffness due to the contribution of other mechanisms in damping like inter-particle water lubrication. Comparison between results of two testing methods indicated a notable influence of initial fabric on G. Furthermore, the overall trends in G and D against N are marginally influenced by initial ψ and Sr. UR - https://scientiairanica.sharif.edu/article_21521.html L1 - https://scientiairanica.sharif.edu/article_21521_12d9602872c5dfc9aad3cce575005588.pdf ER -