Unit Weight of Municipal Solid Waste

TLDR

The unit weight of municipal solid waste (MSW) is a key parameter in landfill engineering, yet its value remains highly uncertain. The study provides guidance for creating landfill‑specific MSW unit weight profiles, including procedures for large‑scale in‑situ measurement. A hyperbolic relationship was derived from in‑situ data and large‑scale laboratory trends to model the characteristic MSW unit weight profile, and the authors outline procedures for large‑scale in‑situ testing. Field data show that each landfill has a characteristic MSW unit weight profile, with specific values largely determined by waste composition, operational practices such as compaction, cover soil placement, liquid management, and confining stress.

Abstract

The unit weight of municipal solid waste (MSW) is an important parameter in engineering analyses of landfill performance, but significant uncertainty currently exists regarding its value. A careful review of reliable field data shows that individual landfills have a characteristic MSW unit weight profile. Based on in situ unit weight data and trends observed in large-scale laboratory tests, a hyperbolic relationship was developed to represent this characteristic MSW unit weight profile. Within the context of this characteristic profile, landfill-specific values of MSW unit weight depend primarily on waste composition, operational practices (i.e., compaction, cover soil placement, and liquids management), and confining stress. Guidance is provided for developing landfill-specific MSW unit weight profiles, including procedures for performing large-scale tests for in situ measurement of MSW unit weight at a landfill.