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.