Correlation between compressibility and degradation for a PTMB waste

Settlement of Municipal Solid Waste (MSW) in landfill is a geotechnical key concern since it could lead to dramatic failure of cap cover systems. On the other hand recent research developments demonstrate that it is possible to propose robust relationship between secondary settlement and kinetics of biodegradation. It is a matter of fact that settlement could be divided into two quasi-independent fractions, a classical time-dependent mechanical contribution, similar to the creep phenomenon for cohesive soils, and a biodegradation contribution. There is a practical interest in this finding: settlement monitored at the surface of the landfill cap cover could be considered as a relevant indicator of the biodegradation level. This is specifically interesting in the case of a landfill bioreactive cell, where the influence of leachate injection in this way could be assessed. The present proposal includes two parts: a presentation of the bio-mechanical relationship through the relation between biogas production and compressibility, and an application to mono-directional (oedometer) tests on MSW.