JOURNAL OF EARTHQUAKE ENGINEERING, vol.15, no.4, pp.601-619, 2011 (SCI-Expanded)
While seismic waves propagate through soil deposits, a part of their energy dissipates which results in a decrease in the amplitude of the applied shear stresses. To better understand the mechanisms leading to the dissipation of applied energy in fine-grained soils, undisturbed specimens having different geotechnical characteristics obtained from a site investigation after 1999 Kocaeli earthquake, were tested in a series of cyclic triaxial tests. Analysis of cyclic test data suggests that portions of fine-grained soil deposits, i.e., silts and clays could have developed high excess pore pressures and significant shear strains during cyclic loadings which contribute to stability problems. The effects of various factors such as confining stress, dynamic stress amplitude, and pore-water pressure accumulation on the cyclic softening of fine-grained soils were investigated and evaluated using the energy criterion.