The construction of a blasting network is challenging, with high risks and costs associated with blasting equipment. Considering the geological structure, physical and mechanical properties of the excavation target, and the detonation characteristics of the detonating cable, a delayed detonation network was designed to combine a digital electronic detonator and a detonating cord. This design replaced the digital electronic detonator with the detonating cord in auxiliary and peripheral holes within the same section. In contrast, a single digital electronic detonator was used to initiate detonation to reduce the networking complexity and improve the overall reliability of the network. Field tests conducted at Guangshan iron mine and Gemstone phosphate mine verified the applicability of this method in different mineral environments. The results show that the fusion delay detonation network can significantly reduce detonation equipment costs, simplify initiation network construction, improve cutting effectiveness, and reduce safety risks during excavating small-section roadways in iron mines. However, during the underground phosphate rock test, the unique geological structure and the properties of phosphate rock prevented the designed network from achieving the expected results, indicating a need for further research.

With the continuous development of blasting equipment, the popularization of high-precision detonator detonators and electronic detonators have been widely used in open-pit bench blasting. However, the definition is vague in the selection of the maximum amount of initiating charge and the distance from the detonation source to the vibration measurement point for the linear regression analysis of the Sadovsky formula when the vibration measurement point is close to the blasting area, and the dispersion position of the blast hole cannot be ignored. A proportional distance was used to measure close-range blasting vibrations by hole blasting. The total charge with a delay interval smaller than 8 ms or the charge quantity nearest to the vibration measurement point was selected as the maximum blasting charge in a section. The distance between the detonation source and the vibration measurement point was selected as the three-dimensional distance between the center of the hole range of the maximum blasting charge and the vibration measurement point or the three-dimensional distance between the hole and the nearest vibration measurement point. The one with a smaller proportional distance was selected for linear regression by comparing the group proportional and single proportional distances. The results show that it has relatively accurate linear regression using this method for the same direction or near the direction of the vibration point value after the noise reduction process.

In order to study the gas diffusion-transport law and the influence of ventilation on the gas concentration of high gas tunnel after blasting, an optimization blasting scheme under gas conditions was carried out, and a gas diffusion-transport characteristic near the working face was investigated under both ventilated and unventilated conditions in a project. The study shows that the residual rate of the blast hole and the utilization rate of the blast hole are above 90%, and the over-excavation control effect is better with an expected blasting footage of 1.2 m and an uncoupling coefficient of 0.76. Under the condition of unventilated condition by numerical simulation, the gas accumulation near the arch top and the arch waist at the tunnel's working face is severe as the gas concentration is close to 30%. Meanwhile, the gas concentration is higher in the area 7 m away from the working surface, and the gas concentration gradient is smaller in the area beyond 7 m after the gas state is stabilized. The gas concentration can be reduced to the safe range around 30 days after ventilation. However, gas accumulation quickly occurs at the arch foot and the arch waist on the other side of the air duct, especially the gas accumulation at the arch foot is more prominent, and the gas concentration is close to 20%. There is a ventilation blind area at the arch foot of the same side of the air duct, and the gas accumulates in a small range as the concentration is about 5%. The monitoring and prevention of the above areas should be strengthened. The field measured gas concentration distribution and gas influence range are consistent with the simulation results, and the research results can provide a reference for similar gas tunnel blasting construction and ventilation optimization.

Taking the explosion of a shipyard as an example, the investigative techniques had been comprehensively utilized (such as on-site investigation, interview, numerical simulation, theoretical calculation, trace analysis, etc.) to conduct in-depth research on the development of the accident, consequences and mechanism of the explosion. An on-site survey of the involved hull revealed fresh welding slag remaining on the starboard main deck in the area of the No. 7 empty cabin utility hole. In addition, the empty compartment No. 7 on the starboard side was identified as the explosion's origin based on the ignition source traces, the extent of the hull damage, and the cracking direction. The root of the explosion accident was restored according to results from a comprehensive on-site investigation. The paint and thinner would volatilize and produce massive organic combustibles during painting operations, forming explosive mixtures when mixed with air and accumulating in the empty compartment's limited space. The explosive gas mixture contacted spattered weld slag at the utility hole, causing an explosion in the empty compartment No. 7 on the starboard side, which triggered explosions in the remaining compartments. As a result of the breeding-development-dissipation of the shock wave, the explosion first intensified and then gradually reduced damage to the surrounding of the NO. 7 empty cabin as the center. The simulation with the CFD analysis software FLUENT revealed that the explosion mixture diffused 10% outward through the utility hole in 12 h. According to the diffusivity analysis results, the gas mixture's volumetric concentration was calculated to be 7.3%, which is sufficient for a combustion explosion. The equivalent amount of TNT for the explosion was 188 kg, which was inverted to 203 kg depending on the extent of damage to the buildings at the accident site after the explosion. It is in good agreement with the TNT equivalent of the explosion obtained from calculations based on the physical parameters of the gas mixture, which proves the practicability of the calculation.

Efficient coordination between different processes is crucial in optimizing resource allocation and minimizing energy consumption during blasting operations in open-pit mines. To address these challenges, the theory of blasting sharing control is proposed, which integrates macroscopic ore fragmentation with mesoscopic damage analysis and introduces a novel ore damage model for the shoveling process. By optimizing inter-process connections and considering factors such as wear and depreciation, a comprehensive energy distribution model is developed across drilling, crushing, blasting, shoveling, and transportation processes. Evaluation and control indices are proposed for each process, leading to the establishment of a blasting sharing control model. The results demonstrate that the ore damage model reveals the multi-phase characteristics of rock blasting failure and effectively predicts the crushing energy consumption by regulating fragmentation levels. With a fitting accuracy exceeding 0.8, this model optimizes the crusher operations while reducing energy consumption. Using the blasting sharing control model enables calculation of the optimal solutions for blast parameter design while establishing an optimal comprehensive energy consumption formula under the constraint conditions, thus enabling the accurate adjustment of energy at each link and providing strong support for efficient, safe, and sustainable mine operations.

The amplification of blasting vibration on rock slopes significantly impacts the accuracy of vibration monitoring and slope safety evaluation. This study investigates the phenomenon through numerical simulation and explores the amplification mechanism based on structural dynamics and vibration mode analysis. The simulation results show that the vibration amplification phenomenon primarily occurs in the vicinity of the bench crest. Influenced by the geometric dimensions of the bench crest and the physical and mechanical parameters of the rock mass, higher peak vibration velocities occur at the bench crest than at the bench toe, due to an increase in platform width, a decrease in bench height, a reduction in the slope ratio and a lower rock mass quality. Conversely, the distribution of the first principal stress exhibits an opposite trend to that of the peak vibration velocity. To improve the accuracy of safety assessments, it is recommended that monitoring points be placed at the bottom line of the bench. The vibration mode analysis further confirms that the amplification effect is predominantly governed by the low-order vibration modes, determined by geometric dimensions and mechanical parameters of the rock mass. The agreement between the mode analysis and numerical simulation results highlights the critical role of low-order vibration modes in controlling the slope's vibration amplification.

The matching relationship between explosives and rocks is crucial for improving the energy utilization efficiency of explosives, enhancing blasting effectiveness, and reducing costs. Firstly, this study analyzed the energy distribution during drilling and blasting operations. Then, the damage zone calculation model was revised considering the non-ideal detonation characteristics of explosives and the strain rate effect on rocks. And an on-site mixed explosives and rock matching model was then developed based on the control of energy transmission efficiency. Finally, field experiments were conducted to verify the rationality of the new explosive-rock matching method. The results show that the new method is more scientific and reasonable than traditional methods, and can intuitively reflect the blasting fragmentation effect and energy utilization efficiency, by taking account of the non-ideal detonation behavior of mixed explosives and the strain rate effects on rock damage partition. Blasting fragmentation tests under various explosive-rock matching conditions revealed discrepancies with the traditional wave impedance theory. By applying the new explosive-rock matching method, the percentage of fines was significantly reduced, and the boulder yield decreased from 6.7% to below 1%, further validating the method's effectiveness.

To investigate the impact of a radially uncoupled charge structure on energy transfer and blasting effects of explosives, with the goal of improving energy efficiency and enhancing rock crushing, dinitrodiazophenol was placed in a standard shale specimen with a diameter of 50 mm and a height of 100 mm. A blasting model experiment was conducted using four radial uncoupled charge coefficients-1, 1.5, 2 and 2.5. The strain waveforms in the axial direction of the specimen were analyzed using the ultra-dynamic strain testing system and the complementary set empirical mode decomposition method. The strain behavior of different sections of the specimen was studied, along with the damage fractal dimension and crack development in these sections. The analysis of the explosive energy propagation laws, combined with the strain curve, revealed that the tensile strain peak values were generally higher than the compressive strain peak values. The specimen eventually failed after experiencing significant and repeated tensile and compressive stresses. Importantly, when the radial uncoupling coefficient was 1.5, the energy utilization of the explosive was significantly improved, along with the prolonged action time of the detonating gas. Additionally, the damage fractal dimension of the specimen section with an uncoupled charge structure changed from top to bottom in an “n-type” manner, resulting in the most uniform damage distribution across each section, a fully expanded crack area, and the best blasting effect.

In order to study the energy evolution and fracture characteristics of sandwich composite rocks under impact loads, six sets of sandwich composite rock specimens were created using three materials: sandstone, marble, and granite. Dynamic fracture impact tests were then conducted using the Hopkinson pressure bar system to analyze crack propagation morphology, stress wave waveform characteristics, crack tip stress field, and energy loss relationship. The DLSM simulation results were also used to analyze the propagation law of stress waves and the evolution process of kinetic energy during dynamic fracture processes. The results showed a good fit between the dynamic fracture process captured by high-speed cameras and the crack propagation process simulated by DLSM. It was observed that the occurrence of cracks depends on the failure of weak bedding planes. Under the same impact conditions, the lower the strength of the weak bedding planes, the shorter and more advanced the crack propagation time, and the more energy is used for crack propagation. Additionally, under the same incident energy conditions, using a specimen with higher hardness as the impact end material results in a stronger reflection effect, greater reflection energy, weaker transmission effect, smaller transmission energy, and greater energy dissipation of the specimen. The bedding plane was found to have a significant hindering effect on the propagation of stress waves.

In order to investigate the mechanical properties and energy transfer law of jointed deep tuff under one-dimensional dynamic loading, seven kinds of tuff specimens with specified natural joint inclinations were tested by SHPB test device. During the tests, the dynamic process was recorded by high-speed camera in real time. The influence of joint inclination angle on the dynamic response characteristics of deep tuffs was systematically analyzed in terms of dynamic strength, energy dissipation and macroscopic damage. The results show that tuffs has the lowest dynamic strength when the joint inclination is 45°, and the dynamic compressive strength and peak strain show a tendency of decreasing firstly and then increasing in the range of joint inclination angle increasing from 0° to 90°. Besides, the final damage modes of the specimens are controlled by the nodal inclination, and the final damage modes of tuff specimens with different nodal inclinations can be classified into tensile damage, tensile-shear composite damage and shear damage. When the incident energy is roughly the same, the reflection energy ratio and transmission energy ratio of tuff present a decrease-increase trend with the increase of natural joint inclination angle, with the lowest energy ratio at 45°. However, the trend of the dissipation energy ratio is opposite. The energy-time density increased first and then decreased with the increase of joint inclination angle. When the direction of load and joint is within 45°~60°, more energy is absorbed and used for self-crack propagation.