摘要
珊瑚砂的孔隙结构对珊瑚砂的力学性质和渗透特性影响显著,采用高分辨率计算机断层扫描仪(computed tomography,简称CT)对珊瑚砂颗粒进行了扫描,建立了珊瑚砂颗粒的三维孔隙结构模型,并对孔隙的直径、体积、紧密度、球度进行了定量分析,采用数值模拟方法探究了松散堆积珊瑚砂及单颗粒珊瑚砂内孔隙结构的渗透特性。试验结果表明:孔隙数量随着孔隙直径的增加显著减少,且微孔数量较多,大孔数量较少;孔隙的直径与紧密度之间为幂函数关系,与球度之间则表现为线性关系。渗流分析结果显示,松散堆积珊瑚砂的渗透能力显示出各向异性,Z方向的绝对渗透率小于X、Y方向。珊瑚砂颗粒内的孔隙渗流速度较慢,不同颗粒之间渗流能力差距较大,部分颗粒不能发生渗流,且颗粒内孔隙的绝对渗透率仅占总绝对渗透率的1.26%。
Porous structure of coral sand has a significant impact on its mechanical properties and permeability characteristics. In this study, computed tomography(CT) was used to scan the coral sand particles, and the three-dimensional pore structure model of the coral sand particles was established in combination with image processing technology. The diameter, volume, compactness, and sphericity of the pores were quantitatively analyzed. Numerical simulation methods were used to examine the permeability characteristics of the pore structure of loosely accumulated coral sand and single-particle coral sand. Experimental results show that the number of pores in the particles decreases significantly with the increase of the pore diameter, which is characterized by a large number of micropores and a small number of macropores. There is a power function relationship between the diameter of the pores and the tightness, and a linear relationship with the sphericity. Seepage analysis results show that the seepage capacity in the Z direction is significantly less than the seepage capacities in the X and Y directions, and the seepage capacity shows anisotropy. Porous seepage velocity in the inner pore of coral sand particles is slow, the seepage capacity gap between different particles is large. In addition, no seepage occurs in some particles, and the absolute permeability of the pores in the particles only accounts for 1.26% of the total absolute permeability.
作者
马登辉
韩迅
关云飞
唐译
MA Deng-hui;HAN Xun;GUAN Yun-fei;TANG Yi(Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210024,China;College of Civil and Transportation,Hohai University,Nanjing,Jiangsu 211100,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2022年第S02期223-230,共8页
Rock and Soil Mechanics
基金
国家重点研发计划(No.2021YFB2600700)
南京水利科学研究院院基金项目(No.Y319006,No.Y321008,No.Y320010)
国家自然科学基金青年基金项目(No.51909171)。
关键词
珊瑚砂
CT
孔隙结构
渗流
三维重构
coral sand
CT
pore structure
seepage
3D reconstruction
