Mechanical behavior of inert waste landfills under seismic condition

Mechanical properties and slope stability of inert waste landfills under seismic condition were studied with three different approaches: in-situ investigation on mechanical parameters, centrifuge model test, and finite element method (FEM) dynamic analysis. Standard penetration test (SPT) showed that penetration resistance (N) value increased with the increase in depth from 0 to 30 m. The shear wave velocities (V_s) for the waste without fiber and with fiber were determined as 175 and 95 m/s, respectively. In centrifuge model test with 50-g centrifugal acceleration, the slope failure behavior of four different cases of landfill models (two cases with fiber and other two without fiber) were studied under the acceleration range of 100–400 gal. The slope stability was enhanced by the tensile resistance offered by the fibrous content. The dynamic response was analyzed using FEM model reproducing the actual slope behavior of landfills with or without fiber under Level 1 earthquake motion representing normal earthquake or Level 2 earthquake motion representing strong earthquake conditions which rarely occur. In FEM dynamic analysis, parametric study confirmed the effect of waste materials, embankment materials and slope gradient. Differences in the failure patterns of centrifuge model tests seemed to be equivalent to dynamic analysis qualitatively.