Effect of crushing on stress-strain & pore pressure behaviour of micaceous kutch soil under monotonic compression & repeated loading-unloading conditions

Abstract

Mica particles are flaky and layered in nature with relatively low hardness as compared to quartz particles. Mica content of more than 10% is not recommended for construction especially for pavements due to high water retention, low compactability and high resilient nature of mica flakes. Limited research has been performed on shear strength behaviour of cohesionless micaceous soils, which is mostly restricted to mica- soil mixture with varying mica content and conventional stress-strain analysis with no crushing effect. The current research is focused on the effect of crushing on stress-strain & pore pressure behaviour of naturally available cohesionless micaceous soil with mica content of 14% under different loading conditions in triaxial testing. The micaceous soil was collected from Dhori (Kutch), and used to prepare the specimens with different degree of crushing by applying various cycles of impact loading until the completion of crushing of mica particles. Six such cycles were conducted on micaceous Kutch soil to obtain the specimens S0 to S6 referring to uncrushed specimen (S0) to highly crushed specimen (S6). A comprehensive experimental research was conducted on these specimens (S0 to S6) to evaluate the effect of crushing on shear & pore pressure behaviour of micaceous soil under different loading conditions of CU triaxial testing;v monotonic compression & repeated loading-unloading. The first CU triaxial series explored the effect of crushing on excess pore pressure evolution, stress-strain behaviour, effective stress path, obliquity, pore pressure parameter, and effective stress ratio of micaceous soil under monotonic compression simulating loading during building construction. In second CU triaxial series, the micaceous soil specimens were subjected to repeated loading-unloading conditions to evaluate the effect of crushing on stress-strain, pore pressure and effective stress path of micaceous soil simulating traffic loading on pavements.