Abstract
Due to formation of shrinkage cracks in landfill clay liners in dry zone of Sri Lanka leads to infiltration of leachate into ground during the rainy season. Therefore, in this research study, shrinkage behaviour of expansive soil available in dry zone of Sri Lanka, which is used to develop compacted clay liners, were evaluated using laboratory desiccation plate tests. Circular desiccation plates with different thicknesses were used for the experiments. A series of tests have been carried out with unamended soil and soil amended with different percentages of bentonite. Further, shrinkage behaviour was studied by amending oleic acid and coconut coir fibers into the soil. Digital image processing technique has been used to determine the Crack Intensity Factor (CIF). Crack initiation time under different configuration was recorded. Based on visual observations, it can be seen that all samples produce predominantly orthogonal crack patterns leading to sub division of crack area in to smaller cells. Higher desiccation rate was observed for smaller thickness of soil specimen. In addition, higher CIF was recorded for the bentonite amended soil. It was noted that shrinkage cracks can be controlled by amending soil with coconut coir fibers.
