Prediction of shear strengths parameters and its application in soil-lime mixture design

The paper presents useful correlations between the shear strength parameters of compacted soil-lime mixtures and the main variables of lime treatment: moisture content, lime amount, curing time, clay fraction and plasticity index of the untreated soil. A case study addressing the reliability of this prediction is shown. The correlations were derived by multiple regression analysis from a database of 35 triaxial compression or direct shear tests on seven soils treated with different amounts of quicklime or hydrated lime. Tests were carried out at different curing times on soil-lime samples compacted at different water contents. The obtained correlations allow to assess the feasibility of the lime treatment and to preliminarily identify the optimum lime type and amount on the basis of the characteristics of the soil to be treated and the required shear strength parameters. The case study concerns the design of embankments for service roads of a landfill constructed along a slope. It shows that the correlations can be a key strategy to select the proper construction method and that they allow reducing the number of laboratory tests to be performed in the design phase.