Prof. D. N. Singh

VENKATA UDAY KALA

Ph. D.
Indian Institute of Technology Bombay, Powai, India uday1112@gmail.com

CRACKING CHARACTERISTICS OF FINE-GRAINED SOILS

Fine-grained soils, subjected to drying, shrink and in critical conditions might even crack. This phenomenon and its ill effects have already been studied by earlier researchers in detail. Based on the investigations, several theories and models that define cracking characteristics of these soils have also been proposed. However, it has been realized that cracking characteristics of these soils are mainly influenced by the environmental conditions (i.e., temperatures and humidity) to which they are exposed to and on their mineralogical composition. To demonstrate this, investigations were conducted on soils of entirely different characteristics and their cracking characteristics, under varied environmental conditions, were investigated by resorting to 'image analysis'. The test results and observations have been critically evaluated and importance of these conditions, which have been quantified in the form of 'evaporation rate' on cracking characteristics of the fine-grained soils, has been demonstrated. Based on the study, a generalized model which facilitates determination of cracking characteristics of these soils, under different environmental conditions, has also been proposed. Also, by resorting to laser microscopy, cracking characteristics of these soils, particularly the depth of crack, has been studied. This study has been found to be quite useful in correlating dimensions of the crack with each other and its volume. Also, efforts have been made in this study to establish a relationship between the tensile strength of these soils and their percentage linear shrinkage, which can be easily measured in a conventional geotechnical laboratory.