Liquefaction behaviour of loose and compacted pond ash

Most of the ash produced all over the world is primarily disposed off by wet disposal method onto the ash ponds, which are occupying huge valuable lands. This disposal problem can be minimized by utilizing ash in large geotechnical earthworks. However, its use in earthquake prone areas requires thorough understanding of its liquefaction resistance and nature of development of excess pore pressures under dynamic loading conditions. Investigations have been carried out in this paper on the liquefaction behaviour of pond ash by conducting cyclic triaxial tests on inflow and outflow ash samples collected from two different ash ponds. Distinctly different liquefaction phenomenon was observed for the ash samples from inflow and outflow points of the same ash pond. Inflow samples exhibited higher cyclic resistance than outflow samples and their strengths were comparable with the natural sands. Further studies revealed that the influence of various factors on liquefaction susceptibility of both the types of ashes is similar to that of natural sands.