Study on Compressibility and Settlement of a Landfill with Aged Municipal Solid Waste: A Case Study in Taizhou

Abstract

Capacity expansion of existing landfills is one of the most economical methods of relieving the stress caused by the disposal of local municipal solid waste (MSW) in developing countries. In this paper, the compression characteristics and settlement of the aged MSW in Xiawan landfill were studied. The physical composition, moisture content, volumetric weight, and modified primary compression index of the aged MSW at different depths were tested, and then the settlement of the MSW in the area to be filled with fly ash was calculated. The test results showed that the main components of the aged MSW were muck and textile, indicating that kitchen waste was degraded. The moisture content of the MSW generally increased with depth, and the average moisture content within 5 m of the shallow part of the landfill was 97%. The void ratio of the aged MSW decreased from 4.0 to 2.2 with an increase in vertical load from 1 kPa to 400 kPa. The modified primary compression index of the aged MSW ranged from 0.22 to 0.27, and generally decreased with depth. Under the load generated by the subsequent filling of fly ash, the final strains of the aged MSW was approximately 15% to 20%. The physical composition and compression characteristics of the aged MSW measured in this paper were compared with those reported in previous studies to provide reference for the settlement analysis of landfills with aged MSW.