Liquefaction Resistance of Solani Sand Under Normal and Sequential Shaking Events

Abstract

Earthquake damage caused by liquefaction is intense and innumerable. This led to the research worldwide on understanding the mechanism and designing suitable ground improvement systems. In the present study, 1g shake table experiments were conducted to investigate the liquefaction resistance and the intrinsic mechanism associated with the sequential shaking events compared to normal shaking events. A tank of dimension 1 × 0.6 × 0.6 m was used for preparing the saturated sand-bed of 25% relative density. Poorly graded liquefiable Solani sand collected from the bed of Solani river near Roorkee, India was used for testing. A total of 8 shaking events were conducted with varying acceleration amplitudes from 0.1g to 0.4g under constant frequency 2 Hz and 1-min shaking duration. In sequential shaking events, the prepared sand-bed was shaken four times in succession with increment in acceleration after the dissipation of pore water pressure. The variation in the generated excess pore-water pressure was monitored continuously using pore-pressure transducers placed at different depths. Sand-bed subjected to sequential events were found susceptible to reliquefaction despite improved sand density under incremental acceleration loading. The experimental data shows that liquefaction resistance increased under the sequential shaking compared to normal events even at higher acceleration amplitude.