To address the accidental explosion risks caused by sensitive primary explosives in industrial electronic detonators, as well as the safety and environmental issues associated with traditional no-primary detonators, a new intelligent flyer-type electronic detonator design was proposed to enhance the safety and environmental performance through flyer initiation technology. To achieve reliable initiation without sensitive primary explosives, a multi-dimensional approach combining experimental and numerical simulation methods is employed for the design and performance optimization of the new intelligent flyer-type electronic detonator. First, critical parameters for slapper initiation were determined through theoretical modeling of shock wave propagation and energy transfer. A finite element model of the flyer acceleration process was established to simulate the effects of different charge structures (e.g., confinement diameter, thickness) on flyer velocity, comprehensively considering material deformation, detonation wave interactions, and flyer fragmentation effects. Second, a high-speed camera (500 kHz) was used to synchronously record the detonation process, capturing the actual velocity, flight attitude, and deformation behavior of the flyer upon target impact. This data was used to validate the numerical model and optimize the structural design of the flyer generator. Third, the axial initiation capability was evaluated through standardized lead plate (5 mm thickness) penetration tests. The penetration depth and crater morphology were comparatively analyzed to quantify performance differences with traditional no-primary detonators. Fourth, an underwater explosion test system was utilized, with an array of pressure sensors measuring shock wave overpressure and bubble pulse energy to assess detonation stability and energy output efficiency. Fifth, donor/acceptor detonator arrays were set up at 10–50 mm intervals, and high-speed cameras were used to monitor sympathetic detonation phenomena, verifying compliance with the industrial safety standard of 40 mm minimum separation distance. Sixth, charge parameters were optimized through iterative testing: primary charge (400 mg, compaction density 1.56 g/cm³), secondary charge (200 mg, compaction density 1.41 g/cm³), tertiary charge (320 mg, loosely packed),the fourth charge layer was eliminated to simplify the production process while maintaining performance. This multi-scale methodology system provides systematic validation support for the reliability, safety, and environmental friendliness of the flyer initiation technology. The results were acquired as follows. Optimized main charge configuration (primary charge: 400 mg-1.56 g/cm³, secondary charge: 200 mg-1.41 g/cm³, tertiary charge: 320 mg-loosely packed) achieved stable detonation, achieve synergistic improvement of detonation performance and safety. When the slapper generator's necking diameter was 5.6−5.7 mm, the flyer velocity reached the reliable initiation threshold. Lead plate tests demonstrated superior axial initiation capability compared to traditional no-primary detonators. Underwater explosion tests confirmed stable detonation performance, with an air-gap sympathetic detonation distance larger than 30 mm, meeting the 40 mm safety requirement for production processes. The innovative elimination of the fourth charge simplified the production process while maintaining high safety and environmental friendliness. The technical bottlenecks of traditional no-primary detonators has been broken. The results show that the new intelligent flyer-type electronic detonator completely avoids the use of sensitive primary explosives through flyer initiation technology. It significantly outperforms traditional designs in initiation reliability, safety distance, and environmental performance, aligning with the industry's trend toward safer and greener detonators. This study provides an innovative solution for the field.

To address the difficulty of blasthole detection during the charging phase of drill-and-blast tunnelling, which is aggravated by dust interference and insufficient illumination, this study proposes an intelligent blasthole detection model based on a hybrid neural network. First, a multi-class classification module accurately categorises blasthole images acquired in complex environments; a feature transformation module then converts these images into equivalent ones with a clear background. Subsequently, a dedicated blasthole detection module identifies the blastholes and localises their positions. By strengthening the feature-extraction capability of deformable convolutions, introducing a triple-attention mechanism, and refining the loss function, the model achieves a significant improvement in detection accuracy under adverse conditions. Experimental results demonstrate that, in complex environments, the proposed model attains a detection precision of 94.47 % and a recall of 86.32 %. Compared with state-of-the-art deep-learning object detectors, the proposed model exhibits superior robustness and blasthole detection capability, reliably identifying blasthole locations that conventional models often miss, thereby providing a solid foundation for intelligent charging in tunnelling excavation.

The influence of reflected explosion stress waves on dynamic crack propagation behavior , as well as the connection between dynamic cracks and pre-existing cracks, was studied using dynamic photoelastic experiments. A high-speed camera was used to capture the full field photoelastic isochromatic fringe pattern of horizontally expanding explosive cracks. The explosive crack is a directional crack generated by detonating explosives in a blast hole containing a horizontal V-shaped groove. The propagation process of explosive cracks can be divided into three different stages. In the first stage, explosive detonation produces dynamic cracks. Simultaneously incident explosion stress waves propagate and interact with prefabricated vertical cracks. In the second stage, the reflected explosion stress waves interact with dynamic cracks. In the third stage, dynamic cracks connect with pre-existing cracks and release unloading stress waves. Considering both singular and non-singular stresses in the near-crack-tip region, three far-field-controlled constant stresses were adopted. The mixed mode stress intensity factor of dynamic cracks under the action of reflected stress waves was analyzed and calculated using the Newton-Raphson iteration method. The results indicate that the leading edge of the reflected pressure wave acts as a stretching wave and the trailing edge behaves as a compression wave. The tensile component of the reflected pressure wave applies tensile stress to the crack tip, increasing the dynamic stress intensity factor K_Ⅰ and promoting crack propagation. On the contrary, the compressive component of the reflected pressure wave applies compressive stress to the crack tip, resulting in a decrease in the dynamic stress intensity factor K_Ⅰ and suppressing crack propagation. Reflected shear waves can cause unstable crack propagation. It causes changes in the direction and velocity of crack propagation, resulting in a wavy crack trajectory. After the penetration of dynamic cracks and prefabricated cracks, the elastic energy stored near the crack tip is rapidly released to generate unloading waves. Due to the action of the unloading wave, stress is concentrated at the tip of the pre-existing crack, causing the formation of a secondary crack at the tip of the pre-existing crack.

The drilling identification technology of surrounding rock lithology can obtain the mechanical parameters of the surrounding rock of the roadway in real time, providing the basic guarantee for the surrounding rock support of the coal mine roadway. Based on the hydraulic anchor drilling rig for coal mine roadways, this paper developed the drilling parameter acquisition system of hydraulic anchor drilling rig in coal mine roadways, including the drilling system, power system, monitoring system and specimen platform. Drilling experiments of combined specimens of mortar of different strengths were carried out using this system. The experimental results indicate that the system shows good performance, obvious variation of the parameters with drilling, and obvious transitions of torque and propulsion pressure at the junction of different rock formations. In order to verify the feasibility of identifying rock strength while drilling, this study calculated the relationship between rock breaking specific energy by means of drilling parameters, and also analyzed the relationship between drilling parameters and compressive strength, it shows that based on the rock breaking specific energy method, the system can realize the identification of rock mechanical parameters by drilling parameters.

Lithology identification while in drilling is a convenient and efficient technology to obtain information about formation. It has the advantages of instant, accurate, environmental protection and energy saving. It can be applied to field of engineering such as rock bound aries determination, support parameter design, blast parameter design, and regional formation strength parameter identification. And it has always been the focus of research by scholars in domestic and foreign. This paper systematically analyzes the research status and development trend of lithology identification while in drilling technology, combined with the application of lithology identification while drilling technology in recent years, discusses the technology of lithology identification while drilling as a new method and new theory of intelligent detection. First, the development history of key technologies for lithology identification while drilling in domestic and foreign is summarized. Secondly, it focuses on the research status, including the technical principle and system composition, and compares and evaluates some typical lithology identification systemsin domestic and foreign. Thirdly, the response relationship between the drilling parameters and the rock during the drilling process is summarized, and the established drilling index and evaluation system, and the factors affecting the lithology identification while drilling is discussed according to the two drilling methods of rotary cutting and rotary cutting-impact. Finally, according to the development trend of the research field of lithology identification while drilling technology, the problems existing in the engineering application at this stage are summarized, and the future research of lithology identification while drilling technology is prospected.