增压式真空预压固结淤泥质软土的试验研究

Experimental Study on Consolidation Characteristics of Mucky Clay Treated with Air-booster Vacuum Preloading

为进一步研究增压式真空预压对软土固结效果的影响,分别进行常规真空预压、通气和注气式真空预压固结淤泥质软土的室内模型试验,对比分析了3种处理方式后软土沉降量、含水率、抗剪强度、土颗粒形态、孔隙结构等宏微观特征差异。结果表明:相较于常规真空预压,通气和注气式真空预压土样沉降量分别增大了5.6%和12.3%;土体骨架颗粒大小更加均匀且排列密实,颗粒接触形式由点接触向面接触过渡,孔隙直径和数量也明显减小;增压式真空预压可以显著增大深部土样抗剪强度,使土体强度更加均匀,其中以注气式真空预压加固软土效果最好,土体抗剪强度增大了11.2 kPa。研究成果有助于揭示增压式真空预压对软土固结效果的影响机制。

To investigate the impact of air-booster vacuum preloading on mucky clay consolidation,we conducted indoor model tests by employing conventional vacuum preloading,ventilated vacuum preloading,and air-injected vacuum preloading,respectively.Analyzing variations in soil settlement,water content,shear strength,soil particle morphology,and micro-pore structure revealed the following findings:in comparison to conventional vacuum preloading,soil settlement increased by approximately 5.6%and 12.3%with ventilated and air-injected vacuum preloading,respectively.Soil microstructure exhibited increased uniformity and density,transitioning from point contact to surface contact between particles.Additionally,both the diameter and quantity of soil pores evidently reduced.Ventilated and air-injected vacuum preloading significantly augmented the shear strength of deep soil,resulting in a more uniform soil matrix.Notably,air-injected vacuum preloading consistently demonstrated superior consolidation performance among the three methods,elevating deep soil shear strength by 11.2 kPa.