真空预压和堆载预压下软土微观结构的变化

The change of soil microstructure under vacuum preloading and surcharge preloading

为揭示真空预压和堆载预压加固软土地基过程中土体微观结构的变化,进一步探究软土加固机理,对温州海底吹填土进行了真空预压试验和堆载预压室内试验,采用电子显微镜研究了2种方法加固软土前后土颗粒的数量、圆形度、直径、丰度及定向性等微观参数的变化.试验结果表明:在真空预压和堆载预压加固软土的过程中土体结构不断调整重组,但加荷方式的差异引起土体结构调整方式不同;真空预压时,土体颗粒重新排列;而堆载预压时,土体颗粒破碎后排列.通过对真空及堆载预压固结过程中土体微观结构变化规律的研究,有助于了解真空预压和堆载预压加固软土的机理与效果.

In order to reveal the change process of microstructure in the process of vacuum preloading and surcharge preloading strengthening soft soil foundation from the microscopic view,and to explore its mechanism of strengthening the soft soil,conducting vacuum preloading and surcharge preloading of dredger fill on Wenzhou seabed are tested in laboratory.Comparison analysis of the soil number,soil circular degree,soil diameter,soil abundance and probability entropy is conduct by laser particles distribution instrument and scanning electron microscopy.The results show that the consolidation process of soft soil by two ways,the process of adjustment and recombination of the soil structure constantly.The ways of adjustment are different because of the loading ways,the soil particles rearrange in vacuum preloading and the soil particles rearrange after being broken.The research of microstructure change rules of vacuum preloading and surcharge preloading favors to explain its mechanism and effect of strengthening soft soil.