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

Area of Science:

• Geotechnical Engineering
• Environmental Engineering
• Earthquake Engineering

Background:

• Earthquakes pose significant risks to landfill stability, potentially causing slope failures and damage to cover/liner systems.
• Such failures can lead to environmental contamination and compromised landfill safety.
• Accurate assessment of the static and dynamic properties of mechanically biologically treated (MBT) waste is essential for seismic analysis.

Purpose of the Study:

• To experimentally investigate the static and dynamic characteristics of MBT waste under seismic loading.
• To simulate realistic stress-strain fields using centrifuge shaking table tests.
• To provide data for enhancing the seismic stability analysis of MBT landfills.

Main Methods:

• Conducted centrifuge shaking table tests on MBT waste specimens.
• Analyzed small-strain shear modulus, dynamic amplification, equivalent shear modulus, and equivalent damping ratio.
• Developed surface equations to model the relationships between these parameters, strain, and depth.

Main Results:

• Determined Poisson's ratio of MBT waste as 0.483.
• Observed a depth-dependent increase in small-strain shear modulus.
• Quantified a dynamic amplification factor between 1.122 and 1.332.
• Established relationships for equivalent shear modulus and damping ratio with strain and depth.
• Found higher equivalent shear modulus and damping ratios in MBT waste compared to municipal solid waste (MSW).

Conclusions:

• MBT waste exhibits distinct seismic characteristics that differ from MSW.
• The developed equations provide a basis for predicting MBT waste behavior under seismic conditions.
• Findings are critical for improving the seismic resilience and safety of MBT landfills.