Experimental Comparison and Study on Small-Strain Damping of Remolded Saturated Soft Clay

Small-strain damping is a key factor of soil behavior under cyclic loading: although the value of small-strain damping is such small that would not compete with damping at larger strains (that would have a more significant impact in dynamic response analyses), repeated energy consumption of the small-strain damping would bring potential abrupt structural failure of soil. However, the measurement methods and fitting models of small-strain damping vary in the accuracy and applicable scope. In this paper, the measurement of SHANTOU remolded saturated soft clay was made for small-strain damping by resonant column apparatus, using both resonant column test method and free vibration test method. On the basis of the experimental data, this paper made a comparison between the two methods and found out the free vibration test method was more favorable for damping measurement at small strains(10⁻⁴% < γ < 10⁻¹%). Based on Davidenkov model, a modified model with the consideration of minimum damping ratio was presented for SHANTOU remolded saturated soft clay in this paper.