Abstract
The study of the permeability of soil-rock mixtures is important in supporting theories behind reclamation mechanisms for open-pit mines. To avoid the influence of differences in the spatial distribution of rock within the same sample on the permeability of a soil-rock mixture in laboratory tests, a numerical method for modelling the soil-rock mixture based on the threshold control method was proposed. Through the statistical results of 297 CT (computed tomography) cross sections of soil-rock mixture samples, the threshold values of pores, soils, and rocks are obtained, and a numerical model representing the reactions of the samples to real-world conditions is obtained. A numerical model was used that could vary with different rock block proportions (RBP) and porosities. Based on Darcy’s law, it is concluded that macroscopic voids greatly increase the permeability of the sample due to their depth of penetration. The higher the stone content, the closer the permeability will be to the permeability of the rock skeleton. Therefore, during the reclamation process of the open-pit mine, the water-retaining layer below the humus should be compacted, and RBP should be increased to lower permeability and achieve better water retention.
Highlights
As China’s environmental requirements improve, reclamation has become increasingly important in the area of open-pit mining
We hope to avoid incorporating error into the laboratory tests caused by differences in materials distribution in the sample, and a numerical simulation based on CT images is a suitable choice
Numerical simulation based on digital images is an effective method to analyse the heterogeneity of materials, the characteristics of their internal structure, the characteristics of various components, and the corresponding mesoscopic properties. is method has achieved positive research results in analysing soil and stone mixtures as well as coal and concrete specimens
Summary
As China’s environmental requirements improve, reclamation has become increasingly important in the area of open-pit mining. A waste dump is the main area of concern in open-pit mine reclamation and is composed of soil-rock mixtures produced by the mining process. Numerical simulation based on digital images is an effective method to analyse the heterogeneity of materials, the characteristics of their internal structure, the characteristics of various components, and the corresponding mesoscopic properties. Liao et al [7] simulated a uniaxial compression test based on a twophase numerical model of soil and stone and concluded that stress in the specimen is affected by the distribution and shape of the stone. Yu et al [11] proposed using bitmap vectorization theory based on the reconstruction method of a three-dimensional, solid material structures model and simulated the uniaxial compression process. For a soilrock mixture, models need to re ect the three phases of soil, block stone, and void space. A threshold control method is established for the soilrock mixture, a multivariable model based on single model is developed, and the relationship between the mesoscopic structure and macroscopic permeability is explored. ese studies provide guidance for the future development of laboratory tests
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
