Establishing relationship between Plasticity Index and Liquid Limit by Simple Linear Regression Analysis

Abstract

A Civil Engineer has to deal with soil in their diverse roles. Every civil engineering structure whether it be a building, a bridge, a tower, an embankment, a road pavement, a railway line, a tunnel or a dam, has to be founded on the soil and thus shall transmit the dead and live loads to the soil stratum. Soil is therefore, the ultimate foundation material which supports the structure. Some clay soil, which are extremely hard when dry, can turn into slush having very little shearing strength, when their water content becomes high. Indeed, water is the most important variable controlling the behaviour of fine grained soil. In practice the property of consistency is associated only with fine grained soils, especially clays. In the present study fine grained soils were selected from different locations of Anekal taluk and basic tests were conducted to determine the physical properties of soil. The obtained Plasticity Index (PI) values in the laboratory were compared Casagrade PI values. An equation is generated between Plasticity Index (PI) and Liquid Limit (LL) using Simple Linear Regression Analysis (SLRA) by Microsoft Excel. The PI values obtained from laboratory results, Predicted PI values obtained from SLRA and PI values obtained from Casagrande equation are compared. It is found that all the PI values are in line/parallel and the equation generated is of very good strength.