Experimental and Numerical Simulation of Stress Distribution in Landfills

This thesis conceptually illustrates stress distribution within landfills by hypothesising the concept of a “hard inclusion”. It was demonstrated, via laboratory experiments and numerical modelling, that the concept of a “hard inclusion” may be partially responsible for elevated stresses measured by Total Earth Pressure Cells (TEPCs) installed within waste in landfills during previous studies as well as horizontal pipe collection/recirculation systems. The high failure rate in horizontal collection systems in engineered landfills and horizontal gas and leachate collection and leachate recirculation systems in bioreactor landfills may be partially attributed to high contrasts in moduli between the bedding material surrounding the pipe collection/recirculation systems and the waste. Similar contrasts in moduli can explain elevated stress measurements obtained by TEPCs to date. It is important to understand the stress distribution in landfills to help landfill designers in the design of collection/recirculation systems.