Dynamic behaviour of micaceous sand with varying mica content and its association with compactability, compressibility and monotonic shear response

Abstract

ABSTRACT Cohesionless soils are highly susceptible to liquefaction under dynamic loading with high-strain amplitude simulating earthquake loading conditions. The presence of flaky mica particles among spherical sand influences the microscopic particle level mechanisms due to complex geometric arrangements caused by bridging, ordering and pore filling phenomena. Such variations substantially affect the compactability, compressibility and shear strength behaviour under monotonic and dynamic loading conditions. The current experimental investigations evaluated the effect of mica content on dynamic behaviour of micaceous sand through a series of strain-controlled cyclic triaxial tests at constant frequency and double axial strain amplitude of 0.5 Hz and 0.6% per cycle. The variation in dynamic parameters such as shear modulus and damping was determined at different mica contents along with cyclic stiffness degradation. Cumulative dissipated strain energy was also estimated to understand the contact-force networks of varying sand and mica matrix from sand-sand to mica-mica through sand-mica particle contact.