Effect of specimen preparation technique on the post-liquefaction behaviour of fine sand under cyclic loading
Indian Geotechnical Journal
School of Engineering
Ministry of Human Resource Development, Government of India
© 2021, Indian Geotechnical Society. Understanding the post-liquefaction behaviour of fine sand helps estimate the stress–strain behaviour and deformations after the occurrence of an earthquake. Several research studies have been conducted to analyse the post-liquefaction behaviour of soil incorporating numerous factors such as relative density, origin/formation of soil, loading intensity and type of loading. The specimen preparation technique has also been found to replicate the fabric characteristics of soils that originated from rivers, offshores, wind or other agencies. In the present study, a comparison between specimens prepared through air pluviation and water sedimentation techniques has been presented for the analysis of post-liquefaction behaviour. The fine sand was collected from the Solani river, Roorkee, India, which is categorized in a high-risk earthquake zone. Strain-controlled cyclic triaxial tests were performed under undrained conditions for two different amplitudes of 0.4 mm and 0.6 mm. To simulate the earthquake aftershocks, multi-staged cyclic loading was applied to the undrained reconsolidated specimens. The results show that the maximum stress carried by the specimens constituted through the water sedimentation technique is 20% more than the air pluviated one during the final stage of the post-liquefaction. The liquefaction resistance is observed in the further rounds of loading. This study has been carried out for two different specimen preparation techniques where the cyclic stress ratio, pore water pressure and stress–strain behaviour have been compared. Through this study, the effect of strain on the post-liquefaction behaviour of fine sand can be understood for the two different soil fabrics formed through the different techniques used.