基于CT技术的巢湖沉积物孔隙结构三维重建的初步研究

Study on the three-dimensional pore structure of sediments in Chaohu Lake based on CT technique

为更好地了解分析沉积物孔隙结构特征,本文通过CT技术及相关软件,对巢湖沉积物孔隙结构进行了三维重建,展现了巢湖沉积物真实的三维孔隙结构,并以此为基础定量计算了孔隙度、孔隙连通性、曲率等沉积物孔隙结构参数.结果表明,巢湖表层沉积物孔隙度变化范围为0.28-0.75;曲率在2.83-9.31内变化,且在不同方向上表现出明显的差异性,Z方向上的较高曲率阻碍了孔隙水中的污染物扩散.沉积柱在垂直方向上,总体上随深度的增加,孔隙度减小,但在某些深度存在异常,可能是因为底栖动物活动或沉积条件变化.

The pore structure characteristics of sediments from Chaohu Lake were studied by using micro-CT three-dimension reconstruction technique,and the related parameters（ porosity,pore connectivity,tortuosity,etc.） were all calculated quantificationally. The results showed that the surface sediments in Chaohu Lake had the porosity of 0.28 - 0.75,and the tortuosity of 2.83 - 9.31 which showed obvious difference in different directions. The higher tortuosity in the Z direction hindered the diffusion of the pollutants in the pore water. In the vertical direction,the porosity of the sediments generally decreased with the increase of depth,but in some depth,there are exceptions,which may be because of the change of the benthic animal activities or the deposition conditions.