Shaking Table Tests on Liquefiable Sand Deposits Treated with Sand Compaction Piles

Abstract

Soil liquefaction and its associated ground failures during earthquake is one of the major hazards causing risk to life and infrastructures. Even though several literatures available using sand compaction pile (SCP) technique, investigations under sequential acceleration conditions for SCP-treated soil deposits were limited. Hence in this study, liquefaction resistance of sand treated with sand compaction pile under sequential acceleration conditions was performed and reported. For experimental studies, an acrylic tank having dimensions of 1.4 m × 1 m × 1 m was selected and mounted on uniaxial shaking table. Soil deposits having 600-mm depth were prepared with 40 and 60% relative density using sand pluviation method. For soil reinforcement, SCP having diameter 110 and 600 mm length was installed inside the soil deposit. Then, shaking table experiments were performed with and without improvement technique under sequential accelerations. For sequential acceleration, the selected accelerations are 0.1, 0.2, 0.3 and 0.4 g with 5 Hz frequency. Initially, the sand deposit was subjected to 0.1 g acceleration amplitude and generation of excess pore water pressure with time was continuously monitored and recorded. After 0.1 g loading, the tank was left undisturbed for 24 h or until complete dissipation of generated pore water pressure whichever earlier. Then, next sequential loading of 0.2 g acceleration amplitude was applied and the same procedure was repeated up to 0.3 and 0.4 g testing conditions. The influence of various parameters affecting the performance of SCP improvement technique under sequential loading was compared and reported.