颗粒形状对碎石料孔隙特性影响研究

Influences of grain shape on pore characteristics of filled breakstone aggregate

颗粒形状是影响碎石料孔隙特性的主要因素之一,进而影响碎石料的渗透特性和力学行为。选取粒径为2~5mm和5~10mm的灰岩碎石颗粒填筑试样,同时与相同级配和孔隙率的玻璃球试样进行对比研究,采用CT扫描技术和图形处理软件获取多孔介质孔隙边界轮廓,选取0.5mm开度阈值分割孔隙;每组试样选取3张扫描断面图像,取定量参数的平均值为研究对象,对孔隙特性进行定量分析。结果表明:玻璃球多孔介质孔隙形状的复杂性甚于碎石料;玻璃球多孔介质孔隙系统的连通度大于同粒组碎石料。

The shape of grains is one of the main factors influencing the structural characteristics of pores in filled breakstone aggregate,subsequently affecting its mechanical and hydraulic properties.Two sets of limestone gravel aggregate with diameters of 2-5mm and 5-10mm were investigated using CT scanning technique and graphic software,from which the pore appearance images of the porous media were acquired.Two sets of glass balls that were with the same granular compositions and porosity as those of the two sets of limestone gravel aggregate were made,and the glass ball sets were compared with the limestone gravel aggregate sets in the test.The threshold value of 0.5mm opening was applied to the segmentation of pore structure.Three section images of each sample were selected so as to quantitatively analyze pore characteristics by means of the average values of quantitative parameters as the research object.The results show that the pore shape in filled glass ball is more complex than that in filled breakstone.The connectivity degree of pore system in filled breakstone is also less than that in glass ball.