High strain dynamic properties of perfectly dry and satureated cohesionless soil
- Vol. 48(3), September
- New York Springer 2018
- 549-557p.
Behaviors of sandy soils under dry and saturated conditions significantly differ from each other, especially under cyclic loading conditions. This paper highlights the behavior of dry and saturated Brahmaputra sand (DBS and SBS) subjected to constant strain monotonic and cyclic triaxial tests. Monotonic tests were conducted on specimens prepared at 60% relative density at a constant deformation rate 1.2 mm/min and varying confining pressures (50, 100, and 150 kPa), while the cyclic tests were conducted with varying cyclic shear strain amplitudes (0.015–7%). Monotonic tests reveal a phase transformation for SBS from contractive to dilative, while DBS shows an ever dilative response. An progressive asymmetric hysteresis behavior was observed under higher cyclic strains, based on which a modified methodology is developed to evaluate the dynamic properties of soil. Beyond 1% shear strain, damping ratio for dry sand was found to follow an asymptotic trend, while the saturated sand exhibited a significant reduction in magnitude. Comparison of the present findings with the standard dynamic models exhibits the importance of conducting site-specific dynamic soil characterization.