Effects of dry density and initial water content on water retention of coral sand
In order to study the effects of dry density and initial water content on water retention of coral sand,soil-water characteristic curves of samples with different dry densities and initial water contents were tested and analyzed by pressure plate apparatus test,and the pore water distribution characteristics of samples under different suction forces were obtained by nuclear magnetic resonance technology.The results show that the air entry value of coral sand increases with the increase of dry density and decreases with the increase of initial water content.The residual water content increases with the increase of dry density and initial water content.In general,the samples with high dry density and initial water content have better water retention.The F-X model has good applicability to soil-water characteristic curves of coral sand samples under different conditions.Dry density and initial water content have important effects on pore size distribution and water retention of compacted coral sand samples,but their effects on water retention gradually weaken with the increase of matric suction.At different suction stages,the effects of dry density and initial water content on water retention of coral sand were different.At 0-10 kPa,the initial water content was the main factor,while at 10-70 kPa,the dry density had a greater effect,and at 70-300 kPa,neither of them had a major effect on water retention of coral sand.The poor connectivity of coral sand pores results in large pores that can still store water under high suction,which enhances the water retention of coral sand to a certain extent.
soil mechanicscoral sandwater retention characteristicsnuclear magnetic resonancepore water distribution
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