Effect of Dynamic Loading on Properties of Saturated Sand

Abstract

Liquefaction has become one of the most important and interesting topics in the field of geotechnical earthquake engineering. Also, its study became a part and parcel of seismic microzonation considering its severity. The devastation brought by it due to earthquakes of Niigata (Japan), Bhuj (India), Nepal has turned the spotlight on the seriousness with which this hazard has to be considered. So, in the present study, a comprehensive experimental program was undertaken in which a series of strain-controlled cyclic triaxial tests were performed to evaluate the liquefaction resistance of local sand in Warangal. Tests were carried out at relative densities, i.e., 35, 50, and 65%, and reduction in pore pressure with increase in relative density was observed. Similarly, confining pressures of 100 and 150 kPa for amplitudes ranging from 0.08 to 1% were also considered. From the results, it was also observed that higher confining pressures resulted in decrease in pore pressure whereas higher amplitude of loading resulted in a rise in pore pressure. This proved that densification or increasing confining pressure improves resistance against liquefaction which can be considered as the cheapest soil improvement technique to mitigate liquefaction hazards in unconstrained areas.