Study on Effect of Enzyme Induced Calcite Precipitation in Fine-Grained Soil

Abstract: When the natural soil cannot satisfy engineering requirements, soil improvement is regarded as a substitute. One of the most common methods for improving the soil in the past was to add cement or lime. There are numerous customised soil improvement methods accessible today. While some treatments are difficult to apply, others are not ecologically friendly. The development of alternatives to mechanical and chemical stabilisation for soil has led to the emergence of bio-stabilization approaches. Enzymes are frequently involved in the bio-stabilization process, which promotes ureolysis and causes calcite to precipitate in the soil mass. Recent studies on sustainable ground improvement techniques suggest that Enzyme Induced Calcite Precipitation (EICP) is a good choice for soil development.Soil sample was silty clay with liquid limit 69%, plastic limit 28.3%, and plasticity index of 40.7%. Soil has an undrained shear strength of 25.4 kPa. By using 2.5 g/l urease enzyme concentration, the liquid limit and plasticity index of the sample decreased by 20.3% and 51.4% respectively and plastic limit of the sample increased by 24.4% after 7 days of curing.By using 5 g/l urease enzyme concentration, the liquid limit and plasticity index of the sample decreased by 21.7% and 62.2% respectively and plastic limit of the sample increased by 36.4% after 7 days of curing