Atterberg Limits Estimation of Pilani Soil Using Ultrasonics

Abstract

Depending on water content, four physical states of soil consistency are used. The water contents at which soil undergoes physical state change are called Atterberg limits. Liquid as well as plastic limit are two commonly used Atterberg limits and are used extensively, either individually or together, with other soil properties to correlate with engineering behavior such as compressibility, compactibility, shrink-swell and shear strength. Conventional method of liquid limit determination requires test to be conducted at 5 (at least) different water contents for accurate estimation. Even liquid limit estimation using cone penetrometer requires experiment to be carried out at more than one water content. Same is applicable for plastic limit estimation. Sand content has effect on its liquid and plastic limit, as well as pulse velocity through it. Consequently, it should be possible to estimate liquid and plastic limit by knowing pulse velocity through it. Pulse velocity using through transmission technique (at constant water content and density); as well as their liquid and plastic limits using conventional techniques at varying sand content were determined and plotted for Pilani soil. This plot can be used as calibration curve for aforementioned estimation purposes and can be developed for other region soils as well.