X-Ray CT Investigation on Fractal Characteristics of Fine-Grained Tailing Sand in Fujian’s Makeng: Insight into the Mesoscopic Seepage Failure

Abstract

This work is aimed at revealing the mesophysical process and mechanical behaviors of fine-grained tailing sand during seepage failure. The macroscopic seepage tests combined with posttest X-ray computed tomography (CT) were employed to study the fractal characteristics of mesostructure. Results show that before and after the seepage failure of fine-grained tailing sand, fractal of pore distribution ( D pd ) and fractal dimension of pore size ( D ps ) show a relatively obvious positive correlation with porosity. Tailing particles migrate along the seepage direction during the seepage process, resulting in the gradual decrease of D pd and pore distribution area. The D ps reflects the variation characteristics of pore number distribution with different pore sizes. The increase in D ps leads to a decrease in the uniformity of pore size and an increase in the size difference between pores. The mass fractal dimension ( D m ) of fine-grained tailing sand samples ranges from 1.6472 to 1.8256. With the increase of D m , the coefficient of uniformity ( C u ) of tailing sand tends to increase. The D m method can discern the seepage failure type of fine-grained tailing sand, and it is more accurate than the traditional method. This study provides a reference for the prevention and control of the seepage failure of tailing dam.

Investigation of the Microstructure Characteristics and Deformation Mechanisms of the Carbonaceous Slate under Hydromechanical Coupling

“…The pore structure of the rock has been studied using a variety of methodologies and techniques, such as the scanning electron microscope (SEM), computed tomography (CT) scanning, nuclear magnetic resonance (NMR), and mercury injection porosimetry (MIP) [16,17]. The combination of various technologies to characterize the pore structure is the main research idea nowadays; the use of appropriate methods to research the rock mass's microstructure properties can reveal the rock mass's strength and deformation mechanism [18].…”