DYNAMIC PROPERTIES OF SOLID-WASTE BASED ON BACK-ANALYSIS OF OII LANDFILL

Back-analyses of the recorded seismic response of the Operating Indust ries, Inc. landfill were performed to estimate strain-dependent shear modulus reduction and material damping relationships for solid waste. Two-dimensional dynamic finite element analyses were performed using t he accelerograms from five earthquake events. The sensitivity of the c omputed results to variations in shear wave velocity, shear modulus re duction, damping, and Poisson's ratio was examined. The recorded and c alculated motions at the top of the landfill were compared through an objective statistical analysis of the computed and recorded accelerati on response spectra. Statistically significant findings from the analy sis indicate that strain-dependent shear modulus reduction and materia l damping relationships for the solid waste at this site ate best char acterized by those of a medium plasticity clay.