Centrifuge model test studies on mechanically-biologically treated waste under seismic loading

Early earthquakes often trigger landfill slope failures and damage to cover and liner systems, resulting in gas leakage, environmental contamination, and significant risks to landfill safety. Accurately assessing the static and dynamic characteristics of mechanically biologically treated (MBT) waste is crucial. Centrifuge shaking table tests offer a robust method to address the limitations of conventional shaking table tests by effectively simulating the static and dynamic stress-strain fields of prototype soils, fulfilling the requirements for comprehensive static and dynamic analysis. Accordingly, this study conducted experimental research on MBT waste using a centrifuge shaking table. Key findings are as follows: (1) The Poisson's ratio of MBT waste is 0.483, and its small-strain shear modulus increases with depth, with a derived equation representing the relationship between small-strain shear modulus and depth. (2) MBT waste demonstrated a significant dynamic amplification effect, with an amplification factor ranging from 1.122 to 1.332. (3) The equivalent shear modulus of MBT waste decreases with increasing strain but increases with depth, with a surface equation established between the equivalent shear modulus, strain, and depth. (4) The equivalent damping ratio of MBT waste varies with strain and depth, and a surface equation was established to capture this relationship. (5) A comparison of the normalized equivalent shear modulus and equivalent damping ratio between MBT waste and municipal solid waste (MSW) shows that both parameters are higher in MBT waste than in MSW. These findings provide valuable insights for seismic stability analysis of MBT landfills.