Applicability of Coal Combustion Products as Vertical Drain Method for Soft Ground Improvement

CPs(Coal Combustion Products) mainly consist of fly ash and bottom ash. In Korea, over 8 million tons of CCPs are generated by 11 coal fired power plants every year. Among them, 80% of fly ash has been recycled as a substitution of cement paste. Meanwhile, the rest fly ashes and bottom ashes are buried in landfill sites. As a result, it is very interesting to reuse or recycle bottom ash based CCPs. Permeability of CCPs which have relatively high volume ratio of bottom ashes are higher than that of clay, and also bottom ashes behave like sand in the mechanical point of view. In this study, based on these properties, a series of composite discharge capacity tests were performed to investigate the applicability of CCPs to vertical drain method in the soft ground improvement. The results show that discharge capacities of CCPs drain are not much different from sand drain or plastic board drain. On the basis of the findings, it may be concluded that CCPs are highly applicable to the soft ground improvement.