In order to study the protective performance of minesweeper protective equipment on the chest and abdomen under the action of explosion shock wave, it is necessary to explore efficient test methods to improve the experimental research index system and overall performance of individual soldier protective equipment. In this paper, two sets of minesweeper protective equipment were taken as experimental research objects, and the real explosion test of minesweeper EOD operators for typical kneeling posture was designed based on Hybird III dummy model under different sealing conditions. The shock wave was generated by the explosion of 50 g TNT charge column. Two wall overpressure sensors were installed in the chest and abdomen of the dummy model to measure the shock wave overpressure generated by four real explosion tests, and a free field pressure sensor was set at the same distance relative to the explosion source to compare the test data. Using the dummy data acquisition system, the whole process data of overpressure on the chest and abdomen after the shock wave penetration of the minesweeper protective equipment were obtained. Through data processing, the pressure-time curve of chest and abdomen subjected to explosion impact and the peak attenuation rate of overpressure were obtained and compared. The test results preliminarily verify that the better the sealing performance of the joint, the higher the protection performance, which indicates that the protective equipment with high sealing performance has a certain blocking attenuation effect on the diffraction of explosion shock wave, and can reduce the damage caused by superimposed overpressure to the chest and abdomen to a certain extent. The experimental design and data analysis in this paper can be used for further equipment performance improvement.

Smooth blasting is the main method for controlling excavations in hard rock tunnels, but due to the complex mechanism and process of rock fragmentation by blasting, as well as the rough design of blast parameters, it is difficult to achieve a smooth excavation profile for the entire tunnel. This study focuses on the Level Ⅲ hard rock section of the Zhaishan tunnel, and through a large number of blasting tests and investigations, it was found that there were problems such as over-excavation and under-excavation, misfire, and secondary blasting construction around the tunnel profile after the original blasting plan was carried out. Based on relevant specifications and engineering experience, optimization measures were proposed for the blasting parameters, including reducing the spacing between contour holes, increasing the number of relief holes, using water bag as the charge decking and stemming, as well as reducing the amount of explosives loaded in each hole. The results showed that the optimization measures can improve the utilization of explosive energy, achieve uniform fragmentation of the rock mass, and control over-excavation and under-excavation of the tunnel perimeter rock mass. The blast parameter optimization also results in smooth and round tunnel profile with clear blast hole marks, which helps to improve the quality of excavation and accelerate the progress of tunnel construction.

In order to investigate the dynamic response, damage evolution and failure of concrete tunnel structure by underwater explosion load, laboratory tests and numerical calculations are adopted in this paper. Firstly, a 40∶1 specimen was designed according to the East Lake underwater tunnel. An explosion test of the underwater box concrete tunnel model was then carried out. The dynamic response rule of the concrete specimens under different emulsion explosive equivalent was compared by monitoring the strains. Meanwhile, the failure forms of the scaled model of the box tunnel caused by the underwater blasting load were investigated by measuring the size of the failure range and the length of crack propagation. Furthermore, a 1∶1 modeling simulation analysis of the test was carried out using the S-ALE algorithm in ANSYS/LSDYNA. It is found that the simulation results were basically consistent with the experimental results by comparing the experimental data and failure patterns. At the same time, the complete propagation process of the underwater explosion shock wave and the deformation law of the specimen structure were obtained by further analysis of the simulation results. Finally, the dynamic response mechanism of the box tunnel specimens under explosion load was revealed through statistical analysis of strain and displacement data at the measuring points. The results show that the transverse strain of the box concrete tunnel structure is much larger than the longitudinal strain. The failure location of the tunnel is mainly concentrated in the area near the explosion source and the structural angle position. It is verified that the S-ALE algorithm can simulate the dynamic response and damage evolution of the structure by underwater explosion accurately.

To mitigate blasting vibration during the excavation of a drainage tunnel located 2.30~3.10 m beneath an existing tunnel, an optimized blasting scheme using millisecond blasting by electronic detonators and a subsection in blasting holes was implemented. The field blasting scheme was initially adjusted based on the conventional blasting situation near the existing tunnel. This involved optimizing hole position parameters and reducing the number of holes. Before the formal blasting in the underpass section, a single-hole blasting test was then conducted near the excavation face to capture the vibration waveform and geological information. Using the linear superposition method, the vibration waveform of various delay intervals was analyzed to select the optimal delay interval. To further improve blasting performance and reduce the vibration of the cut blasting, the first blasting in the cut area was performed by using the subsection blasting in the hole. Field tests and calculations determined that the optimal delay times were 5 ms for the same row of cut holes or spreader holes, 40 ms between rows, and 3 ms for contour holes. The new blasting scheme was implemented and optimized in the field. When the drainage tunnel was excavated at a footage of 1.5 m through the existing tunnel, the maximum vibration of the road surface monitoring point at a distance of 3.10 m directly above was maintained below 4.0 cm/s, ensuring structure safety. Using electronic detonators for precise initiation and sectional blasting successfully controlled site vibration, protected adjacent structures, and provided valuable insights for similar future projects.

The original stope benches of Dahuangshan Open-pit Mine were in disarray, with pumice between benchs and steep slope conditions. Following blasting operations, a crushing system was introduced to improve rock fragmentation efficiency, significantly increasing potential safety risks near high and steep slopes. This study researched safe blasting techniques and protective measures for slopes in open-pit mines to ensure slope safety during blasting construction. Active protection methods were proposed, including limiting instantaneous charge to 200 kg, aligning the blasting direction parallel to the slope, and preserving approximately 5 m of rock wall along the slope edge. Protective infrastructure was enhanced by installing two protective nets on a cleaning platform mid-slope, excavating a 7 m-deep and 20 m-wide stone protection ditch at the foot of the slope, building a 2 m-high stone protection wall using crushed stones outside of the ditch, and erecting a 2 m-high isolation net outside the protection wall. These safety measures were complemented by auxiliary monitoring methods to enhance the safety of blasting operations and protect the crushing system. Field inspections confirmed that the construction methods effectively ensured the stability of the high-steep slopes and minimized risks during blasting.

The long burial time, severe corrosion and damage of waste ammunition pose extremely high safety risks. Improper handling or disposal of such unstable ordnance may lead to serious negative impact on society. Taking the disposal work of waste ammunition in Hunan Province as the research object, this paper summarized the main disposal methods, analysed the existing problems, and proposed countermeasures and suggestions to enhance the disposal capabilities. To explore the shortcomings of the current disposal methods, the characteristics of waste ammunition (such as types, age, and conditions) had been analysed by field research and relevant literature. The study reveals that China's waste ammunition disposal system confronts several critical challenges, including: (1) insufficient technical expertise among disposal personnel; (2) inadequate development of specialized storage infrastructure; (3) scarcity of specialized disposal equipment; (4) technological limitations in destruction methodologies; (5) an underdeveloped regulatory framework and institutional mechanisms for disposal operations. To address these challenges, this study proposes a comprehensive set of countermeasures: (1) enhancing specialized personnel training programs to improve technical competencies; (2) upgrading construction standards for dedicated storage facilities to ensure safety and compliance; (3) deploying advanced disposal equipment to increase operational efficiency; (4) developing innovative destruction technologies through targeted research; (5) standardizing disposal mechanisms to establish robust regulatory frameworks. The conclusion indicates that implementing scientific and standardized waste ammunition disposal protocols holds critical importance for mitigating public safety risks and safeguarding civilian lives and property. Future development should prioritize to enhance technological innovation and systematic improve management frameworks. These dual focus areas will collectively elevate operational standards and efficacy in waste ammunition disposal practices.

In order to select the shaped charge structure with low residual height and small fragmentation after blasting of concrete base, numerical simulation method is used to study the motion characteristics of jet flows formed by 60° and 120° conical liners and explosive formed projectiles (EFP) formed by curved liners with curvature radius of 10.8 cm as well as the vertical penetration process and damage effect on concrete bases under the same explosive charge, outer diameter and shaped charge liner thickness. The results show that: Different shaped charge penetrators have different penetration modes to concrete bases. The head part of the jet flow formed by the 60° conical liner penetrates the concrete base first, and then the pestle part expands the hole. For the 120° conical liner, the pestle body and the jet flow penetrate the concrete base together, while the curved liner mainly penetrates the concrete base by the formed projectile; the crushing capacity of the shaped charge is related to the diameter of penetration hole. The larger the hole diameter is, the stronger the crushing capacity is. The penetration hole diameters of 60° liner, 120° liner and EFP liner are 4.3 cm, 5.2 cm and 7.0 cm, respectively. In addition, the number and width of cracks formed within the penetration depth show an increasing trend; the residual height of the concrete base after blasting is related to the distance between the transverse through cracks and the bottom, while the formation of transverse cracks is related to multiple factors such as penetrator parameters, charge quantity and so on; for the concrete base with a limited size, a shaped charge liner with a large cone angle has a better comprehensive effect with respect to crushing range and degree. Although the penetration ability of EFP liner is the weakest and the residual height of the concrete base after blasting is large, its crushing ability within the penetration depth is the strongest. The study of blasting effect of different shaped charge penetrators on a concrete base can provide a reference for exploring damage mechanism and selecting destruction mode.

The dislocation and overbreak of tunnel inverted arch are serious when traditional blasting excavation technology is used. This is because traditional blasting technology does not adopt the smooth blasting method, and the angle of the perimeter holes is too large when drilled by manual rock drilling rigs. By therefore analyzing the traditional blasting excavation technique of invert, the cause of serious studiedthe smooth blasting technology for inverted arch is proposed based on the smooth blasting theory and a large quantity of engineering practice. Water decking charge structure is adopted in the perimeter holes, which can be adjusted according to the inverted arch shape. The spacing between the perimeter holes is 30~50 cm, and the thickness of the smooth blasting layer is greater than the perimeter hole spacing by 10~30 cm. Additionally, a drilling counterforce support is used to reduce the angle of the perimeter holes which can ensure each blast hole to be drilled to the design depth. After comparing the blasting effects of the proposed smooth blasting technology and traditional blasting technology for the inverted arch by field tests, the contour overbreak by the smooth blasting technology is far less than that of traditional blasting technology, and the cost of every 12 m tunnel excavation is reduced by 35.14%.

In open-pit bench blasting, blasting TBlasting toe rocks is an important indicator to measure the blasting effect in open-pit bench blasting, and it is most directly influenced by the blasting parameters have the most direct influence on the formation of blasting toes. In order to find outresearch the influence of ultra-deepsubdrilling on the smoothness flatness of bench in deep-hole bench blasting, statistical analysis of the relationship between damage variables and wave velocity in rock mass was conducted based on the basic theories of rock damage mechanics. based on the basic theories of rock damage mechanics and through statistical analysis of the relationship between damage variables in engineering and wave velocity in rocks, Tthe threshold values of damage variable, D_d for critical damage variable damage state of of rock mass is determined as Dd that is was 0.2, and the damage threshold D_t of for rock breaking mass in critical broken state is was were defined as 0.2 and 0.8, respectively. based on the basic theories of rock damage mechanics and through statistical analysis of the relationship between damage variables in engineering and wave velocity in rocks. Furthermore, Based on the dynamic damage model of rock with comprehensive consideration of the damage effect of tension and compression, the damage range of bench blasting under different conditions of with different subdrilling conditionsultra-deep was simulated by using the dynamic finite element analysis program LS-DYNA based on the dynamic damage model of rock mass with a comprehensive consideration of tension and compression effect. Meanwhile; based on the threshold of critical damage variable, the fluctuations distribution image of the bench surface after blasting was drawn to determine the optimal ultra-deep of subdrilling hole based on D_t the threshold of critical damage variable, and the image is was used for the quantitative analysis, so as to ensure that the rock mass of upper bench was fully damaged without affecting the construction of the lower bench surface. Finally, combined with the actual situation of deep-hole bench blasting in Ezhou Airport, the influence mechanism of ultra-deepsubdrilling on blasting toes is was verified in the deep-hole bench blasting of Ezhou Airport, and an optimal method for determining the optimal ultra-deepsubdrilling value for deep-hole bench blasting is was concluded.

The drilling and blasting method is widely used in tunnel excavation. Typically, smooth blasting can meet the quality formation requirements. However, achieving ideal contour control blasting effects and ensuring the safety and stability of surrounding rock mass are challenging due to limitations in drilling conditions and charging in small section tunnels, especially when encountering adverse geological conditions. This often results in increased costs for subsequent support and lining. To address these issues, on-site blasting tests were conducted based on small-section hydraulic tunnels to explore applying energy-gathering hydraulic blasting technology to improve blasting parameters in poor geological conditions. The main conclusions from analyzing and evaluating the quality of contour excavation using 3D laser scanning technology are as follows: (1) The results indicate that shaped charge blasting can reduce over-excavation and under-excavation by 40.8% and 54.2%, respectively, compared to conventional blasting under the same geological conditions. (2) A comparative analysis of blasting results under different borehole arrangements shows that no boreholes are needed to connect the arch crown and the side wall. Utilizing the shaped charge effect to control can reduce over-excavation at the arch shoulder. (3) In fourth-class surrounding rock mass, including silty mudstone and stratified sandstone, the smoothness of the wall surface is less affected by blasting parameters and is promarily determined by lithology. Moreover, the smoothness of stratified sandstone can be improved by more than 30% compared to silty mudstone. In summary, the reasonable application of shaped charge water pressure blasting technology in small cross-section hydraulic tunnels can improve tunnel wall shaping under smooth blasting conditions.