Browsing by Author "jayasinghe, Poornima"

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    Settlement Behavior of Bioreactor Landfills
    (2024-09-18) Abeysiri Munasinghage, Saranga Adeesha; Hettiaratchi, Joseph Patrick; Wong, Ron Chik-Kwong; jayasinghe, Poornima; Sadeghpour, Farnaz
    Settlement prediction of bioreactor landfills is crucial for the many stages of design, construction, operation, maintenance, and reconstruction. Settlement can both increase the capacity of a landfill and extend its lifespan. Accurate settlement prediction is particularly crucial when assessing spatial requirements, organizing the construction order, and building interim and permanent covers. Researchers have conducted numerous studies in recent years to examine the settlement processes in MSW landfills. These investigations have employed various methods such as laboratory testing, in-situ settlement monitoring, and numerical modelling. This dissertation presents an analysis of the settlement behavior of the Calgary Biocell, a waste cell operated as an anaerobic landfill bioreactor for 15 years at the Shephard landfill in Calgary, Alberta, Canada. Time-dependent post-closure settlement of the landfill was measured using a geographic information system-based methodology involving the formation of a grid on the landfill surface until the waste cell excavation for resource recovery and space reclamation in 2022. The settlement data reveals that leachate recirculation and landfill gas extraction expedited the waste cell settlement of the Calgary Biocell throughout its operating period. A settlement model proposed by Hettiarachchi et al. (2007, 2009), which considers both gas pressure and moisture distribution in predicting the settlement behavior, was employed in the post-analysis. Most model input parameters were derived from on-site data, and missing values were selected based on relevant literature. The model output yielded results comparable with the time-dependent waste settlement data observed throughout the Biocell operation. The predicted total settlement is approximately 20.71% closely aligning with the actual total settlement of 21.68% over the 15-year operation of an anaerobic landfill bioreactor. Additionally, a comparison is being made between the settlement data received from several bioreactor landfill projects in other countries and the data obtained from the Calgary Biocell. Leachate recirculation was revealed to be a factor in greater settlements.