压汞法对不同深度软土固结的微观孔隙特征研究

软土的微观孔隙特征对软土的固结特性以及渗透特性有较大的影响。压汞法是广泛应用于研究材料孔隙特征的方法,利用压汞法对不同深度的珠海原状软土在不同的固结压力下进行了微观孔隙特征测试。对比研究了软土孔隙大小分布、孔隙面积、孔隙比以及平均孔径与固结压力的关系。试验结果表明:软土在固结过程中孔隙特征的变化受原状初始物理性质的影响;软土试样随着固结压力的增大,由孔径为400 nm—2500 nm区段的孔隙逐渐发展为孔径30 nm—400 nm区段的孔隙,即固结过程中软土试样的较大孔隙逐渐转变为较小孔隙;软土试样在固结压力100 kPa200 kPa,孔隙比及平均孔径仍在减小,但速度减慢,曲线近于平缓。

The study of micro pore characteristics on different depth soft soil consolidation by mercury intrusion porosimetry

The micro pore characteristics of soft soil have great effects on consolidation and permeability properties. Mercury intrusion porosimetry is a widely used method for studying porous materials. The micro pore characteristic of Zhuhai undisturbed soft soil with different depth is tested under different consolidation pressure by mercury intrusion porosimetry. The relationship is studied comparatively among pore size distribution, pore area, average pore size, with the consolidation pressures. The results show that the pore characteristic of undisturbed soft soil is affected by initial physical properties in the process of consolidation. With the increase of consolidation pressure, the pore sizes change from the zone of 400nm-2500nm to 30nm-400nm. That is, the bigger pores of soft soil sample gradually change to smaller pore in the consolidation process. When the consolidation pressure is between 100kPa and 200kPa, the porosity and average pore size diminish quickly. While the consolidation pressure is greater than 200kPa, the porosity and average pore size also diminish, but slow down, and the curve change to gently.