IDENTIFICATION OF THE GOVERNING MECHANISM IN THE BEHAVIOR OF SILTY SAND

Abstract

The behaviour of soil varies due to its diverse mineral compositions and particle sizes. Soil can be classified into two main groups: fine-grained soils, which are influenced by electrostatic forces, and coarse-grained soils, which are governed by gravity. While most studies have focused on sand and clay, there is another soil type called silt that falls between them in terms of particle size. Silt can behave similarly to clay when it possesses plasticity, while non-plastic silt exhibits characteristics similar to sand, such as dilation under shearing and liquefaction under cyclic stress. However, silt behaves differently from both clay and sand due to its unique characteristics. One possible reason for this behavioural shift in silt, where it compresses and then dilates during shearing with a delay, could be the reduction in particle size compared to sand particles. To investigate the variations in silt behaviour, several tests including relative density and standard proctor tests were conducted on sand, silt, and different combinations of sand-silt mixtures. This study aims to explore the governing force behind silt behaviour. The proposed mechanism for determining the governing force in silt is adapted from powder technology. As a result, a new test called the cylindrical flow test is suggested, which allows the determination of the force using the kinetic energy formula. This study outlines the mechanism governing silt behaviour and the technique employed to determine it.