渗流作用下吹填土微观结构特征定量化研究

Quantitative Research on Microstructure Features of Dredger Fill Under Seepage Flow

吹填土的工程性状受土体的物质组成和微观结构综合影响,而微观结构在以往的研究中涉及较少。以天津滨海地区吹填土为研究对象,进行室内渗流作用下吹填土的沉降试验。利用图像处理技术对土体的微观结构作定量分析,讨论天津滨海地区吹填土结构单元体、孔隙的大小、丰度和定向频率等评价指标在渗流作用下的变化情况及形成机理,可为评价吹填土的工程地质性质提供一定的理论依据。试验分析表明：随着渗流压力的增大,土中结构单元体从较为松散的状态转变为团聚状态,呈现出不同程度的扁圆形,但没有明显定向性;土体中的孔隙由于失去平衡,变为小而紧密的球形体,孔隙定向角集中分布在0°~10°。

More and more engineering geological characters of solidified dredger fill are concerned due to the faster increase of number of reclamation engineering.It has been studied that the engineering behavior of dredger fill is mainly influenced by the material composition and microstructure,within which,the latter is indispensable but seldom involved.Taking dredger fill in Tianjin as study sample,indoor sedimentation test in the effect of seepage is performed along with quantificational analysis of microstructure of soil using image processing technology.And then,the changing of evaluation indicators,such as the size of structure element and pore,abundance,and directional frequency are discussed.The result indicates that,with the increase of seepage pressure,the dispersed structural elements of soil become agglomerated elements displaying a variety of oblate but without directing property.Simultaneously,the pores in the soil are diminished and compacted to be globoid ones after losing balance.