吹填土渗流固结过程微观结构的分形特征

摘要

In order to analyze the change law of the microstructure of dredger fill in the process of seepage flow consolidation, the fractal theory was applied to quantitatively describe the structural characteristics of the microstructure of dredger fill and analyze the curing mechanism of dredger fill. Laboratory tests, including granule analysis and soluble salt tests, were conducted to evaluate the engineering geological properties of dredger fill in the new coastal region of Tianjin. Based on the fractal theory, a quantitative analysis of the microstructure photos of samples was performed by the WD-5 picture processing system, and the changing regularity of the fractal dimension of dredger fill in the new coastal region in the process of seepage flow consolidation was investigated. The result shows that with the increase of seepage pressure, the morphology fractal dimension of structure elements of dredger fill in the new coastal region increases, while the box-counting fractal dimension decreases. Besides, the arrangement of structure elements tends to be dense and the morphology becomes complex. With the increase of consolidation load, the morphology fractal dimension of pores in the dredger fill increases, while the box-counting fractal dimension decreases. Meanwhile, small pores in the dredger fill increase, the volume of pores decreases, and the complexity enhances.%为分析渗流作用下吹填土固结过程中微观结构的变化规律,应用分形理论,定量描述吹填土的微观结构特征,探讨吹填土的固化机理.通过吹填过程的室内模拟试验,对天津滨海新区最终沉降的吹填土进行了颗粒分析试验和易溶盐试验,以评价吹填土的工程地质性质；基于分形理论,采用WD-5图像处理系统,对试样的微观结构进行了定量分析,讨论了渗流固结作用下天津滨海新区吹填土在渗流固结过程中微观结构分形维数的变化规律.研究表明:随渗流压力增大,天津滨海新区吹填土结构单元体的形态分形维数逐渐增大,而计盒分形维数减小,结构单元体排列致密,形态复杂性增强；随固结荷载增大,天津滨海新区吹填土中孔隙的形态分形维数增大,计盒分形维数减小,土中小孔隙的含量增加,孔隙体积减小,复杂性增加.