With open-pit mines excavated, the slopes will be exposed to the natural environment for a long time. Affected by factors like temperature, seepage, mining, freeze-thaw, etc., slope structural integrity and strength will gradually decline as slope exposure time extends. Besides, the development of defect structure within the rocks is closely correlated with time. In this paper, freeze-thaw cycle tests were conducted on the saturated sandstones collected from a certain open-pit mine. According to the test results, the mass density and longitudinal wave velocity gradually increased with more times of freeze-thaw cycles while mechanical properties such as internal friction angle, cohesion, elastic modulus, and uniaxial compressive strength decreased instead. The constitutive model of saturated rock deterioration was established by taking the volume of phase transition of water in microcracks as a variable. Based on the tests results and theoretical analysis, the sensitivity of the factors affecting slope stability under freeze-thaw damage was studied by Control Variable Method (CVM) and Orthogonal Design Method (ODM). It was determined that the internal friction angle and cohesion had a highly significant effect on the test results, while the mass density had a significant effect. The conclusions may play a certain role in guiding slope construction and protection.

The waste dump is a giant artificial loose pile body composed of fine, medium, and coarse particle sizes. Rising incidents of landslides caused by overburden pressure and effective pressure are of increasing concern in the open-pit waste dump and, if not well-controlled, are a dangerous threat to the workers, the environment, and the equipment. The purpose of this research is to investigate the connection between effective pressure, porosity, void ratio, and coefficient of permeability and to find their influence in the open-pit waste dump. This study analyzed the mechanical and physical changes of seven different soil samples using consolidation and permeability under consolidation laboratory test. The test samples were subject to a pressure ranging from 100 to 1600 kPa. The effective pressure was found to play a major role in influencing void ratio, porosity, and coefficient of permeability, and waste dump height management and control are of great importance. This study answers the question regarding the correlation between effective pressure, void ratio, porosity, and coefficient of permeability in the open-pit waste dump. Further studies are needed to establish profound relationships and develop preventative measures to keep the waste dump slope stable and safe.

In an effort to enhance the efficiency and safety of open-pit mines, this study explores the optimization of end slope road parameters and slope structures, specifically focusing on unmanned driving lanes. A significant aspect of the study is the development of a truck trajectory offset model, which considers the different reaction times between automated sensors and human drivers in adapting to environmental changes. To test these concepts, the study uses numerical simulations to confirm the stability of the proposed end slope designs. Using Victory West Mine No. 1 as a case study, the research determines the optimized width for unmanned driving lanes and the maximum angle for the safe steepening of end slopes. The findings indicate that the optimized unmanned lane width for NTE240 mining dump trucks is 1743 mm, allowing for a 2-degree increase in the slope angle at the south end slope. This optimization leads to a steep mining stripping volume of 3.2735 million m³ and a coal output of 2.49628 million tons, maintaining a stripping ratio of 1.31 m³/t. These results demonstrate that unmanned driving road width optimization not only ensures slope safety but also significantly boosts the economic benefits of steep mining in open-pit mines.