THE INFLUENCE OF PORE SIZE DISTRIBUTION AND RADIAL CONSOLIDATION PROPERTIES ON THE LIQUEFACTION POTENTIAL OF SILTS

Abstract

From the work done following the 1999 earthquakes, a new method called The Adapazari Criteria has been proposed. A study to understand the contribution of the pores thus hydraulic conductivity and dissipation characteristics, on liquefiability of fine grained soils was attempted. The soil water characteristic curves for 16 reconstituted silty soils have been prepared by the pressure plate and filter paper methods than pore size distribution of the samples have been determined. Dissipation characteristics of samples have been measured with a hydraulic cell at laboratory and radial consolidation characteristics have been also measured in the process by means of piezometers embedded in the cell wall. The results show that pore size distribution curves for liquefiable and non-liquefiable samples are significantly different. It is found that those samples with average pore size of r(50)<0.0004 mm are not liquefaction prone. In addition, a limit curve has been developed that separates zones of liquefaction and non-liquefaction zones. Average radial consolidation coefficient values at 10% clay ratio can be said to be around 10 m(2)/year. Soil samples have liquefaction potential according to Adapazari Criteria and dynamic tests which have less than 10% clay content, exhibit similar dissipation curves as a soft parabolic decreasing type curves. Dissipation curves of samples which have more than 10% clay content, make a sudden drop after the pore water pressure valf is opened then the curves rise but not to exceed the maximum value at the initial loading phase and decreases like a soft parabolic curve again. Upward trend that does not have the potential liquefaction of the samples with initial curve is fading.