高浓度黏性泥沙絮团微观结构及其对沉降特性的影响

Microstructure of cohesive sediment flocs with high concentration and its influence on the deposition characteristics

为探究絮团微观结构特征与高浓度黏性泥沙沉降特性间的关系,以高岭土沉降实验为基础,采用电镜扫描技术分析絮团结构,从絮团微观结构角度解释黏性泥沙沉降过程中浓度分布、胶凝点浓度等特性,结合实验数据讨论常见的孔隙形态参数。结果表明:絮团的微观结构与黏性泥沙的沉降特性密切相关,沉降过程中垂向浓度分布、胶凝点浓度等特性均可通过对絮团内部结构的分析得到合理解释;孔隙分形维数、孔隙圆度可作为量化评估孔隙结构的有效参数;由于孔隙的形态、数目、大小的差异,孔隙率的大小与孔隙分形维数、孔隙圆度的关联度不大。

Based on the deposition experiments with Kaolin clay,the floc structure was analyzed in combine with electron microscopy scanning technology to study its influence on the deposition process.The sediment settling characters are explained by the microstructure of mud flocs.The morphological parameters of pores were discussed with experimental data.The results show that the microstructure of flocs is closely related to the deposition characteristics of viscous sediments.The vertical concentration distribution and gel point concentration during the deposition process can be explained by analyzing the internal structure of the flocs.The pore structure can be quantitatively evaluated with pore fractal dimension and pore roundness.Due to the differences of pore shapes,number and sizes,porosity has little correlation with pore fractal dimension and pore roundness.