Parameter determination of a compression model for landfilled municipal solid waste: an experimental study

Area of Science:

• Geotechnical Engineering
• Environmental Engineering
• Waste Management

Background:

• Landfilled municipal solid waste (MSW) undergoes significant compression over time.
• Accurate modeling of MSW compression is crucial for predicting settlement and landfill stability.
• Existing models often simplify the complex biodegradation processes influencing secondary compression.

Purpose of the Study:

• To investigate methods for determining parameters of a one-dimensional compression model for MSW.
• To evaluate the accuracy of current models in simulating biodegradation-induced secondary compression.
• To propose improvements for more realistic MSW compression modeling.

Main Methods:

• Conducted long-term laboratory compression experiments on MSW under varying surcharge loads (100, 200, 400 kPa).
• Determined primary compression indexes, pre-consolidation pressure, and ultimate secondary compression strain using measured data and a creep index.
• Analyzed the biodegradation-induced compression rate coefficient's influence on model predictions.

Main Results:

• The study identified that a constant biodegradation-induced compression rate coefficient fails to capture measured secondary compression behavior.
• Simulated compression using constant rate coefficients did not accurately represent actual MSW settlement.
• The rate of biodegradation significantly influences the secondary compression strain over time.

Conclusions:

• The biodegradation-induced compression rate coefficient is not constant and varies with the decomposition rate.
• For accurate modeling, the compression model must incorporate an incremental form for biodegradation-induced secondary compression.
• This approach enhances the predictive capability of MSW compression models, considering dynamic decomposition processes.