Behaviour of soil under cyclic loading

Raghunandan, M.E., and Juneja, A. (2010)., Indian Geotechnical Conference, Mumbai, India, Vol. 1, 195-198, 2010

During seismic loading, natural soil is subjected to cyclic shear stresses at different amplitudes and frequencies that will induce transient and permanent deformations. Literatures demonstrate the significant influence of dynamic soils properties on the response and stability of soil layers. The objective of this paper is to address some of these issues. Strain controlled cyclic triaxial tests were conducted at +/-0.4% cyclic shear strains and 1Hz frequency on large 100mm diameter and 200mm high reconstituted triaxial samples prepared using soil samples collected from a pilot area in Mumbai, and a clean sand sample. The response of soil samples to applied shear strains are presented as decrease in cyclic stress and development of pore pressure with number of loading cycles. Further, response of the soil is compared with that of clean sand. Results showed that the soil samples are less susceptible to liquefaction compared to clean sand, with G and D values around 9 ×104kN/m2 and 15% respectively at 0.4% shear strains.