ESTABLISHING RELATIONSHIP BETWEEN CBR WITH DIFFERENT SOIL PROPERTIES

Abstract

In the flexible pavements sub-grade is considered to be an ideal layer to resist wheel load and its CBR value is considered as the strength measuring parameter. Conducting CBR test is an expensive and time consuming test, moreover it is very difficult to mould the sample at a desired in-situ density in the laboratory. Further, if the available soil is of poor quality, suitable additives are mixed with soil and resulting strength of soil is assessed by CBR value which is cumbersome. To overcome these problems, the other methods such as regression based models (simple & multiple) are used in this study. The soil properties like liquid limit, plastic limit, plasticity index, optimum moisture content, maximum dry density and percentage fineness of the soil (passing 75micron sieve) are determined for the soil collected from different areas of Bagalkot district and the models are developed for correlating soaked CBR value. Keywords: CBR, regression models, liquid limit, plastic limit, plasticity index, optimum moisture content and maximum dry density.