Effect of Sustainable Column Materials on Compressibility Characteristics of Decomposed MSW Through Model Study

Over a period of time, municipal solid waste decomposes and converts into material having 70–80% soil content. MSW has a sandy gradation, but it has a water affinity, which makes it more compressible. The composition of this waste varies from place to place, as do its geotechnical properties. This waste material can be used as fill material for construction sites, or old landfills themselves can be used as construction sites. However, because of its organic content and fibrous composition, it is compressible in nature and requires long-term geotechnical techniques to reduce compressibility and increase load carrying capacity. As per the Central Pollution Control Board (CPCB), only 28% of collected waste is treated, and the rest is dumped in landfills, which need to be sustainably utilized. The composition of MSW in India is approximately 40–60% compostable, 30–50% inert, and 10–30% recyclable. This will be a complete dual task of waste utilisation and fill material independence from borrow pits. In India, the rate of generation of C&D waste annually increases by 5%, and approximately 40% of fly ash remains unutilized every year, which needs to be utilized. The objective of the present research work is to determine the load-settling characteristics of old MSW by infusing sand, fly ash, lime and C&D waste columns, respectively, from the top. The present work is mainly focused on the improvement in load settlement characteristics like axial load carrying capacity, load resistance, settlement reduction factor, and stress concentration ratio obtained due to the infusion of various column materials.