Effect of Dynamic Compaction on the Compressibility Characteristics of Municipal Solid Waste, Under the Saturated and Unsaturated Conditions

The scarcity of land suitable for new developments in urban areas is a growing problem in many countries. In Sri Lanka, open dumping has caused unsanitary landfills within major cities, and it is economically, socially, and environmentally desirable to rehabilitate them. Ground improvement is a significant step in the rehabilitation of landfills, and dynamic compaction (DC) is a commonly used method in treating heterogeneous fill materials such as municipal solid waste (MSW). In this study, MSW samples obtained from the Meethotamulla landfill site, Sri Lanka, subjected to DC under both saturated and unsaturated conditions, were tested using the Rowe cell apparatus. Their compressibility characteristics were established under four conditions: saturated-compacted, saturated-noncompacted, unsaturated-compacted, and unsaturated-noncompacted. The results of the analysis indicated that the improvement of density and compressibility characteristics of MSW due to DC is greater under the unsaturated condition. In addition, the results were compared with that of preloading. It was found that preloading is more effective in improving the compressibility of MSW under both saturated and unsaturated conditions.