The impact energy produced by blast casting is able to break and cast rocks, yet the strong vibration effects caused at the same time would threaten the safety of mines. Based on the theory of Janbu’s Limit Equilibrium Method (LEM), pseudo-static method has been incorporated to analyze the influence of dynamic loads of blasting on slope stability. The horizontal loads produced by blast vibrations cause an increase in sliding forces, and this leads to a lower slope stability coefficient. When the tensile stresses of the two adjacent blast holes are greater than the tensile strength of rock mass, the radical oriented cracks are formed, which is the precondition for the formation of presplit face. Thus, the formula for calculating the blast hole spacing of presplit blasting can be obtained. Based on the analysis of the principles of vibration tester and vibration pick-up in detecting blast vibrations, a detection scheme of blast vibration is worked out by taking the blast area with precrack rear and non-precrack side of the detection object. The detection and research results of blast vibration show that presplit blasting can reduce the attenuation coefficient of stress wave by half, and the vibration absorption ratio could reach 50.2%; the impact of dynamic loads on the end-wall slope stability coefficient is 1.98%, which proves that presplit blasting plays an important role in shock absorption of blast casting.

During the research on bench deep-hole blast casting, the blast-casting parameters are directly related to the blast-casting results, so it could reveal the mechanism for improving the effect thereof. Based on the principle of the plane charge method, both the stress wave and detonation gas were considered to affect rock fragmentation and casting, a model of overburden fragmentation and casting process around the blasting hole was established, and bench deep-hole blast-casting behaviours were elucidated. By using the Factor Analysis Method (FAM), a correlation analysis model of factors influencing blast-casting results was built. The results proved that powder factor (or specific charge) ranked first in terms of its influence, followed by hole spacing, minimum resistance line, burden, and bench height. The formulae for calculating the limit powder factor value and the spacing of blasting holes were derived for different rock properties. The results showed that the optimum hole spacing was no more than 12.49 m and the powder factor was no more than 0.75 kg/m³, and it proved that an effective casting percentage (ECP) of 34% could be realized.

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.

An automatic recognition of discontinuities in borehole images is a desirable way to overcome the inefficiency and inconsistency inherent in the conventional method of manual annotation. The rough borehole walls and prominent noise failed the application of existing recognition methods to borehole images taken in the coal-measure strata. This paper presents a novel approach to automatically convert coal-measure strata borehole images into identified discontinuity maps. The developed procedure formed an integrated feature representation for the borehole image through combining the color information of image and the textural features generated from multi-channel filtering. Image regions containing discontinuities are then separated from other regions by implementing fuzzy c-means clustering on the acquired feature representation. The identification of discontinuities is finally accomplished by searching for four predefined patterns (named topographic model) on the intensity transection of image regions. The proposed method is proven to be superior in the respects of noise suppression, discontinuity positioning, and recognition completeness.

According to the principles of bionics and predatory behavior of dolphins, Leader Dolphin Herd Algorithm (LDHA) was designed, whose performance is also tested on the basis of heuristic algorithm, showing that LDHA is obviously superior to the other algorithms in calculation accuracy and efficiency. The minimum safety factor of sliding surface was taken as the objective function, the recurrence formula of safety factor based on simplified Bishop Method was regarded as constraint condition, a non-linear multi-objective optimization mathematical model used for analyzing slope stability was established. the process of searching slope sliding surface and solving safety factor were designed on account of LDHA. By taking homogeneous slope and layered slope as calculation examples compared to other intelligent algorithms, the results show that the calculation result of LDHA is close to that of Genetic Algorithm and Simulated Annealing Algorithm and improved Genetic Algorithm. Moreover, the LDHA has less iterations and faster convergence rate, and the result is closer to the optimal solution, which indicates the feasibility and practicability of LDHA in solving the minimum stability safety factor.

In order to achieve the goal of ecological restoration, plant irrigation, and water retention in the external dump of open‐pit coal mine in the arid desert area, it is proposed to use the mudstone in the stripped material to reconstruct the surface aquiclude and improve the water holding capacity of the topsoil. By taking the Hongshaquan Open‐Pit Coal Mine as the study object, the red mudstone of mining level +650 was selected as the topsoil aquiclude material through the geological survey. XRD diffraction experiments are used to determine the composition of red mudstone including kaolinite mineral, quartz, potash feldspar, albite, and illite. The moisture content of the red mudstone is 4.16% as measured by the indoor drying experiment. And the particle size of 0.5 mm, 1 mm, and 2 mm and the thickness of 5 cm, 10 cm, and 20 cm rock samples were selected to conduct the indoor soil column experiment. Three indicators of initial infiltration rate, stable infiltration rate, and average infiltration rate were obtained according to the analysis and calculation of the water column drop rate, wet peak drop rate, and cumulative infiltration rate so that the permeability law and coefficient of each group of tests can be known. The finite element transient analysis theory and numerical simulation method were adopted to verify the results of physical experiments. The research results show that +650 level red mudstone has a strong antiseepage ability, and the smaller the particle size, the better the antiseepage performance. For 0.5 mm and 2 mm particle sizes, as the paving height increases, the water‐proof effect is better. The laying height of 1 mm particle size has no obvious influence on the water barrier effect. The physical simulation was confirmed to have the same result trend as the numerical simulation, both of which are quadratic functions with the error within a reasonable range.