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.

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.

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.

Taking the “6·13” major gas explosion accident in Shiyan as the research object, this work constructed an accident investigation technique integrating scene investigation, interview and inquiry, numerical calculation and theoretical analysis. During the scene investigation, it was found that a section of DN57 mm medium pressure natural gas pipeline remained in the river below the southeast corner of the market. The pipe was adjacent to the domestic sewage drainage outlet, and it was rusted and partially ruptured due to the long-term wet environment. Meanwhile, yellowish natural gas fume was first found in the river at the southeast corner by video monitoring, visits and inquiries from surrounding residents, which led to the result that the aforementioned pipeline was the leak point. In addition, some merchants were engaged in flame operations before the accident. Some sparks entered the river through the smoke exhaust pipe and ignited the premixed combustible gas accumulated in the river, which resulted in the explosion. A numerical model of the river was established by the ANSYS/FLUENT software, and the volume of the natural gas accumulated in the riverway was 600 m³, which explosive TNT equivalent was 225 kg. The gas volume and explosion equivalent are consistent with the data published in the accident investigation, which proves the feasibility of this analysis method.

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 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.

The DBDP Hydropower Station, the largest hydropower station under construction in Pakistan, faces challenges related to blasting vibration affecting freshly poured concrete of the proposed intake tower of the diversion tunnel. Finite element calculation parameters were adjusted based on on-site blasting vibration monitoring data to address this issue. A numerical simulation method was utilized to analyze the blasting vibration response of the water intake tower under various blasting conditions and to identify factors influencing peak particle velocity (PPV). The study proposes measures to control blasting vibration. The results indicated that the maximum charge per delay, the delay time between blast holes, the advancing direction, and the detonation position significantly impact the intake tower's vibration. It is recommended that the maximum charge per delay and the delay time between blast holes be controlled to mitigate vibration on the fresh concrete. Additionally, adopting a backward blasting advancing direction and hole-bottom initiation is advisable.

There are hundreds of blast holes in a tunnel blasting. Since the traditional manual drawing of the blasting scheme is laborious and depends on the experience of blasting engineering, a digital method for the planar and three-dimensional spatial distribution of blast holes was proposed based on formula derivation to study an intelligent design method for tunnel blasting blast holes. Subsequently, the programming of blast hole parameters was achieved by utilizing computer programming techniques, which can lead to the development of an intelligent blast hole design system. The results show that the parametric expression method of tunnel contour, cut holes, peripheral holes and auxiliary holes can realize their rapid creation and meet the needs of tunnel blasting. By establishing a correlation between the coordinates of the blast hole opening and bottom, a refined expression of the spatial distribution of the blast hole can be realized, and intuitive guidance for on-site drilling operations can be provided. Furthermore, a computer programming method can realize an intelligent and fine design of a blast hole layout. After tunnel blasting, the residual marks of the blast holes are complete, the contour of the tunnel excavation is smooth, and the overall excavation effect is good. The research results can improve the efficiency and intelligence of tunnel blast hole design.

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%.