河道淤泥气泡混合土强度发挥及微观机理分析

Strength properties and microscopic mechanism analysis of foamed soil with river sludge

为研究土体内部微孔分布特征对河道淤泥气泡混合土强度发挥的影响,利用数字图像分析方法对河道淤泥气泡混合土内部微孔分布进行了定性及定量分析。试验结果显示,在试验条件下河道淤泥气泡混合土内部优势微孔孔组为等效孔径0.06~0.08 mm与0.20~0.40 mm两个孔组,混合土强度发挥与优势孔组在土中的分布特征具有密切的相关性;增大气泡掺量导致较大孔径孔组微孔数量及面积占比增大,微孔孔径分布不均匀程度提高,混合土强度及刚度降低;增加水泥掺量使混合土中较大孔径孔组微孔数量及面积占比减小,混合土强度及刚度均得到提高。

In order to study the influence of the distribution characteristics of micro pores in soil on the strength of foamed soil with river sludge,the digital image analysis method was applied on the qualitative and quantitative analysis of the micro pore distribution in the foamed soil with river sludge.The experimental results show that the pore groups with 0.06-0.08 mm and 0.20-0.40 mm equivalent aperture are dominant pore groups in foamed soil with river sludge under laboratory condition,the strength of foamed soil with river sludge is closely related to the distribution characteristics of dominant pore groups;the increase of the foam amount will lead to the increase of the number and area proportion of the larger size pore group,the increase of inhomogeneity of pore size distribution,and the decrease of the strength and stiffness of foamed soil with river sludge;the increase of the cement content makes the number and area proportion of the larger size pore group in the foamed soil with river sludge decrease,and the strength and stiffness of foamed soil with river sludge are improved.