Global void ratio of municipal solid waste for compression indices estimation

Area of Science:

• Geotechnical Engineering
• Environmental Engineering
• Waste Management

Background:

• Landfill stability and functionality depend on municipal solid waste (MSW) compressibility.
• Existing correlations between MSW properties and compression parameters lack accuracy or have limited applicability.
• A comprehensive dataset is needed to develop reliable predictive models for MSW compression behavior.

Purpose of the Study:

• To develop a novel method for estimating MSW compression indices using the initial global void ratio (e0*).
• To establish correlations between e0* and various MSW compression parameters.
• To provide a practical tool for predicting MSW compression and strain in landfills globally.

Main Methods:

• Categorized MSW into biodegradable (B), reinforcing (R), and inert (I) fractions with suggested specific gravity values.
• Calculated initial global void ratio (e0*) using initial dry unit weight (γd,0) and ternary MSW composition.
• Developed correlations between e0* and immediate, secondary mechanical creep, and bio-compression indices using a dataset of 124 MSW compression results from 44 studies across 13 countries.

Main Results:

• Established clear correlations between e0* and immediate compression index, secondary compression index (mechanical creep), and secondary compression index (bio-compression).
• The developed method is applicable to MSW with a wide range of compositions (B: 0-79.2%, R: 0-54.0%, I: 2.8-100.0%) and initial dry unit weights (γd,0: 2.0-14.2 kN/m³).
• A simple flowchart was created to facilitate the estimation of MSW compression indices and strains.

Conclusions:

• The initial global void ratio (e0*) is an effective parameter for estimating MSW compression indices.
• The developed method offers improved accuracy and broader applicability for predicting landfill settlement and stability.
• The findings support better landfill design and management practices worldwide, considering diverse MSW characteristics and environmental conditions.