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.

Presplit blasting can reduce vibration and back impact induced by cast blasting, thus resulting in a smooth bench slope. To design reasonable presplit blasting parameters, this research investigated the formation of presplit faces based on the explosion mechanics and revealed the cracking mechanism of presplit blasting. According to the stress distribution in the vicinity of the blast holes under the action of explosive stress waves and blasting gas, we deduced theoretical formulae for parameters including charge mass in blast holes, hole spacing, and distance from presplit blast holes to cushion holes. On this basis, a method was proposed for the design of large‐diameter deep‐hole presplit blasting. Field testing was conducted by setting different spacing for presplit blast holes, to monitor the blasting‐induced vibration. The results showed that appropriate hole spacing can reduce the particle vibration velocity and the attenuation index of blasting‐induced vibration changed slightly while the attenuation coefficient decreased significantly; the formed presplit faces were smooth and had a high half‐cast factor. Finally, the reasonable hole spacing for presplit blasting, distance from presplit blast hole to the cushion hole, and the charge mass in blast holes in the Heidaigou open‐pit coal mine were determined, respectively.

Rock mass blastability classification provides a theoretical basis for rock mass blasting design, which is used to select blasting explosives, to estimate the unit explosive consumption, and to determine blasting design parameters. The primary factors that affect rock mass blastability were analyzed by selecting five indexes for rock mass blastability classification, that is, the rock Protodyakonov coefficient, rock tensile strength, rock density, rock wave impedance, and integrity coefficient of rock mass, and by identifying standards for the rock mass blastability classification and a method for testing the blasting classification indexes. The index weights were calculated using the combination weight method, which is based on game theory. A model for rock mass blastability classification was developed in combination with a fuzzy pattern recognition method. This classification method was applied to a Heidaigou open-pit coal mine, where mudstone, fine sandstone, medium sandstone, and coarse sandstone were determined to have a blastability degree of II, which corresponds to a blastability characterization of “easy,” and the unit explosive consumption of mudstone, fine sandstone, medium sandstone, and coarse sandstone was determined to be 0.44, 0.42, 0.40, and 0.36 kg/m³, respectively. These results were used to develop a loose blasting design that was effective for loose blasting.

Step blasting is an important part of open-pit mining, which is accompanied by hazards such as large blasting blocks, flying stone splashing, blasting noises, and blasting dust during the blasting process. In order to reduce the harm caused by blasting, this paper uses impact dynamics and rock dynamics to explain the deformation damage and motion law caused by detonation of the material blocked by the gun hole. By simulating the motion of the blocked material in the gun hole, the motion and failure characteristics of the blocked material in the gun hole are revealed. In this paper, geological polymer is introduced into the field of open-pit mine blasting, and 700 g rock powder, 200 g slag, 40 g NaOH solution (30%), and 140 g water glass with a modulus of 3.2 and 80 g of water are selected to prepare geological polymer-modified plugging materials to change rock powder blockage from bulk to solid, and improve the plugging performance. Finally, a field test was carried out in the open-pit mine explosion area, and a comparative test was carried out through the high-speed photography system; it is demonstrated that the modified blocking material could improve the blockage ability of the gun hole, reduce the large block rate of the upper part of the step, reduce the amount of dust, reduce the amount of flying stone, and improve the production efficiency and safety.

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.