Dynamic shear modulus and damping ratio for threshold strain in cohesionless soils
Based on modern ideas of thermomechanics, small strain dynamic dissipation function of HardinDrnevich model for soils is formulated using the assumptions of the beeline and the skeleton curve shift laws. Fundamentally, for cohesionless soils, two types of cyclic strain thresholds are identified: first threshold strain and second threshold strain represent boundaries between fundamentally different dynamic characteristics of cyclic soil behavior. Comparison between the two threshold shear strain values and dynamic degradation curves obtained on exactly the same soils, the results showed that the ratio of secant modulus and maximum dynamic shear modulus for the first threshold strain are almost 1.0, and the damping ratio is almost constant. When dynamic strain level exceeds the second threshold strain, the soil behavior is considerably at nonlinear, and the primary deformation mechanism is related to fabric changes during cyclic loading. The first and the second threshold strains are therefore essential for th e understanding and solving soil dynamic problems.
Dynamic characteristic Cyclic shear strain Dynamic modulus Damping ratio
Xiaoxia Guo
State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian 116023, China
国际会议
上海
英文
1603-1606
2011-10-21（万方平台首次上网日期，不代表论文的发表时间）