由于土体微观结构具有多向性及不均匀性,可以使用分形模型来模拟土的微观结构并对其进行定量描述.基于Sierpinski分形模型,对珠江三角洲地区软土固结过程中的ESEM图片进行测试,分析软土固结过程中的微观特征变化,定义了一个能够反映软土孔隙的大小、形状、分布以及排列定向性的微观参数——孔隙结构影响因子Fs.研究表明,孔隙结构影响因子能够正确评价软土孔隙的变化,与固结荷载、渗透系数以及压缩系数都具有十分明显的相关性;同级荷载下,原状土的孔隙结构影响因子比重塑土的要大,但是当荷载增加到一定程度时,两者趋于一致;当固结荷载增加到一定程度时,孔隙结构影响因子的地区差异减弱,最终都趋于18左右.%As the microstructure of soil is politropic and heterogeneous, the microstructure of soil can be simulated by fractal model and described with fractal parameters. The Pearl River Delta(PRD) soft soil environmental scanning electron microscope (ESEM) pictures are tested and the change of microscopic features in the process of soft soil consolidation analyzed based on the Sierpinski fractal model. A parameter which reflects the size, shape, distribution and orientation in the alignment of soft soil pore is defined and this parameter named as impact factor of pore. The research shows that this parameter can give a correct evaluation to the change of soft soil pore. There is an obvious relativity between this parameter and the consolidation load, the permeability coefficient and the compression coefficient. The parameter of natural soil is larger than the remolded soil in the same consolidation load, but they are equal when the load is large enough. The parameters which come from different areas would be the same when the consolidation load is large enough and approximates 18.
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