This study aims to analyze the damage evolution law of the surrounding rock mass in an ultra-deep shaft under blasting load. To achieve this, a numerical simulation method is adopted based on the blasting construction practice of Xiling Auxiliary Shaft in Sanshandao Gold Mine. The simulation utilizes a restart technology based on ANSYS/LS-DYNA and adopts the equivalent explosion load method according to the blasting design scheme. The surrounding rock mass damage of the ultra-deep shaft is calculated under four different ground stresses (15 MPa, 30 MPa, 45 MPa, and 60 MPa) and four different side pressure coefficients (1.0, 1.25, 1.5, and 2.0). Furthermore, this study analyzes the damage effect on the shaft's surrounding rock mass and investigates how ground stress and side pressure coefficient influence the extent of damage to the surrounding rock. The numerical results demonstrate that as ground stress increases from 15 MPa to 60 MPa, there is a significant inhibition in the damage area with a decrease in radius from 5.75 m to 3.4 m. Additionally, it is observed that with an increase in lateral pressure coefficient, there is anisotropy in terms of blasting damage area distribution where greater ground stress leads to concentrated damage areas.

The distribution of blasting fragmentation in open pit mines has a direct impact on subsequent excavation, transportation, and crushing operations. To effectively control the fragmentation distribution of blasted rocks in different regions of graphite mines, a new model for evaluating rock blastability was developed using the K-means unsupervised cluster learning method and entropy weight TOPSIS evaluation method. Evaluation indexes including rock density, dynamic energy dissipation rate, dynamic compressive strength, average strain rate, and brittleness index were selected. Through entropy weight calculation, it was determined that the degree of rock breakage is most influenced by the brittleness index and least influenced by the average strain rate. The model was then applied to an actual graphite mine to assess its effectiveness. The rock blastability was divided into 10 grades based on this evaluation model. The average particle size of rocks under different grades was calculated and it was observed that as blastability grade increased, so did the average particle size. This finding demonstrates clear classification characteristics and validates the efficacy of our model. From the perspective of rock mass type of graphite ore, the rock explosibility is ranked from easy to difficult: schist, gneiss, granodiorite, mixed rock. Combined with the analysis of microscopic observation results of graphite ore, it can be seen that the lithology changes from schist to mixed rock, and the graphite crystalline content in the rock decreases, and the graphite ore explosibility grade is also higher and higher. Additionally, there exists a linear positive relationship between density/energy dissipation rate/dynamic compressive strength with rock blastability while negative correlation is observed with respect to average strain rate/brittleness index.

The contour forming effect of a hard rock tunnel is of significant importance in enhancing the stability of surrounding rock and reducing support costs. This paper aims to optimize the single-hole charge and charge structure for tunnel contour holes. The theoretical range of charge parameters for blasting contour holes in tunnels is proposed initially. Subsequently, blasting tests were conducted on a hard rock tunnel using single-hole charges of 1200 g, 900 g, 750 g, and 600 g respectively, with all tunnel contours analyzed by a laser scanner. Finally, a fracture mechanics model was employed to simulate the contour blasting of the hard rock tunnel with different single-hole charges. The results indicate that when charging parameters are within a reasonable range, smaller single-hole charges result in fewer cracks between blasting holes and less damage to the surrounding rock. Although decreasing the charging amount from 1200 g to 600 g reduces over-excavation volume from 6.53 m³ to 2.02 m³, it also increases under-excavation volume caused by hole position error from 0.15 m³ to 0.26 m³ along the tunnel contour. Furthermore, compared to the damage mechanics model, the fracture mechanics model proves superior in simulating contour blasting for hard rock tunnels as evidenced by good agreement between calculated results and experimental data regarding half hole numbers on the tunnel's contour.

To study the explosion equivalent of DT-3 and its influencing factors caused by fire stimulus during storage, transportation and use, the propagate detonation ability of that was studied by the extremely insensitive to detonating substances (EIDS) gap test. High-speed cameras and a shock wave pressure acquisition system were utilized to obtain information on the deflagration processes and shock wave hazards of DT-3 under external flame effect. Additionally, an infrared thermal imager was employed to determine the highest temperature of the surface fireball. Further calculations were conducted to determine the explosive TNT equivalent of 18 kg and 120 kg DT-3 samples. The experimental results indicate that direct exposure to a strong shockwave does not cause DT-3 propagation detonation. However, different packing strengths can lead to deflagration events under external fire conditions, potentially resulting in an overall detonation reaction. The average TNT equivalents for standard packaged 18 kg and 120 kg DT-3 samples were found to be 0.629 and 0.0293 respectively. Furthermore, there is no positive correlation between the scale effect and shock wave impact. Under fire stimulus conditions, package design strength significantly influences the explosive characteristics of DT-3. To enhance safety measures, it is recommended that package design strength be reduced within acceptable limits for actual usage in order to effectively mitigate the risk of detonation hazard.

In order to analyze the attenuation effect of multi-layer bubble film on underwater explosive shock wave, an underwater explosion test was conducted to obtain shock wave parameters with a No. 8 industrial electric detonator as the explosion source. The bubble film was designed with different specifications and different layers of air insulation structure. Furthermore, the shock wave overpressure peak value and specific shock wave energy were compared based on the shock wave parameters. The results show that the attenuation rate of shock wave overpressure peak increases with the increase of bubble film number, with the attenuation rates of 1#, 2#, 3#and 4#bubble film increasing from 48.32%, 86.08%, 87.87% and 90.34% to 89.10%, 91.33%, 91.45% and 92.37%, respectively, which implies that the normal film has less influence on the attenuation of underwater shock wave without air interlayers. Specifically, a larger bubble diameter can reach a better attenuation effect with the same number of layers, which indicates that the bubble plays an important role in attenuating shock waves. In addition, the specific shock wave energy consumption of the bubble film is more than 98.50%. In practical applications, bubble film can be used as a protective material, which can effectively reduce the harmful effects caused by shock waves on the protected objects.

Rock blastability classification is a prerequisite for determining labour quotas, designing blasting programmes and controlling the unit consumption of explosives. In order to realize a real-time grading of rock explodability, a measurement of in-situ drilling parameters of carbon-bearing muddy dolomite during the excavation process of ore body and roadway in the Shukongping phosphorus mine has been carried out based on the KJ212-1 full-hydraulic boring drilling truck. Combined with the indoor uniaxial compressive strength test, the relationship model between the uniaxial compressive strength R_c and the drilling speed V, the drilling hole diameter D and the rotary pressure M was respectively established and verified. Finally, the model is substituted into the solidity coefficient f relationship equation to derive a model for the relationship between the blasthole drill-following parameters and the rock blastability classification. The results of the study show that the average rate of difference between the uniaxial compressive strength calculated by the relational model and the results of the indoor uniaxial compression tests is 5.5%, which demonstrates the reasonableness of applying the model to the real-time prediction of rock blastability. This model provides a more convenient and fast method for real-time grading prediction of rock blastability. The results show that the dolomitic banded phosphorite, mud banded phosphorite and dense banded phosphorite are medium explosive, carbon-bearing mud dolomite is difficult to explode.

Air overpressure generated from the blasting excavation may affect the safety of surrounding structures. The blasting operation area of the horizontal tunnel of the second phase of Meizhou Pumped storage power station is only 81 m away from the steel accident gate of the upper drainage tunnel of the second phase project, which has been built and put into the operation in the first phase. However, the blasting may affect the operation stable of the accident gate. Therefore, taking the blasting excavation of the horizontal hole above the water diversion of the second phase of Meizhou pumped storage power station as the object, the field monitoring of blasting air overpressure was carried out. The distribution rule of blasting air overpressure and its influence on the safety of the emergency gate in the upper reservoir of Meizhou pumped storage power station were analyzed, which provided support for analyzing the influence of blasting air overpressure on the safety of the emergency gate in the upper reservoir. The blasting air overpressure monitoring data show that the air overpressure level in front of the accident gate about 80 m away from the blasting master surface is distributed at 0.63~3.46 kPa, which is much smaller than the suggested corresponding blasting safety control standard of 100 kPa. The protective facilities before the gate can effectively reduce the air overpressure at the gate position, and the measured air overpressure in the fourth and fifth blasting is reduced by more than 55%. When the single and total charge volume are effectively controlled, the measured air overpressure value is much smaller than the suggested control standard value. Besides, there is no abnormality in the field macro investigation and other detection data, the blasting construction does not affect the safe operation of the accident gate on the reservoir.

Gaseous detonation synthesis is a novel approach for the production of carbon nanomaterials. This method offers several advantages over other techniques, including rapid reaction kinetics, diverse product types, high yield, exceptional purity, straightforward operation, and cost-effectiveness. These benefits make it highly suitable for promoting the industrial-scale manufacturing of carbon nanomaterials. To elucidate the current research and development status of gaseous detonation-synthesized carbon nanomaterials, this paper provides an overview of the necessary instruments and equipment, experimental procedures, theoretical calculations, and product characterization methods employed in this synthesis technique. Additionally, it summarizes the technologies and methodologies used to synthesize various carbon-based materials such as carbon-coated nanometallic particles, carbon nanospheres, carbon nanotubes (CNTs), carbon dots (CDs), and carbon nanocapsules via gaseous detonation synthesis. The morphology of these synthesized products is analyzed along with their structural features and performance characteristics. Furthermore, this study explores the potential applications and technological advancements associated with these newly developed gaseous detonation-synthesized carbon nanomaterials to lay a solid theoretical foundation for rational design optimization and large-scale production of nanostructured materials in line with industry standards in explosive engineering. Current research indicates that the synthesis of detonation should be integrated with both macroscopic detonation theory and microscopic particle growth. The investigation of detonation wave engine and the analysis of detonation cell structure have become prominent areas of study, particularly in understanding the relationship between macroscopic detonation cells and the microscopic synthesis process of nanomaterials. However, a significant challenge remains in comprehending the growth mechanism of particles synthesized through detonation on a micro-scale, necessitating the utilization of molecular dynamics and lattice Boltzmann calculation methods for resolution.

The blasting construction of water conservancy projects is characterized by its long duration and large scale. However, traditional methods for blasting design and construction control are inadequate to meet the requirements of current water conservancy project development. Therefore, it is crucial to study and establish a platform-based, networked, and intelligent blasting design and control system with significant engineering significance. To achieve this goal, this research adopts a front-end and back-end separation method using the Angular framework and SpringBoot framework based on BIM (Building Information Modeling), WebGIS (Geographic Information System), and developed blasting design software. The system comprises an intelligent blasting design module, three-dimensional visualization module, digital blasting control module, as well as an intelligent safety evaluation and prediction/warning module. This integration enables intelligent blasting design along with comprehensive auditing functions throughout the entire process. Importantly, the system can select control points on the excavation contour line for intelligent blasting design based on actual site conditions. It generates blast design schemes that undergo review using a model parameterized dynamic joint cropping method before being uploaded. This approach promotes standardization, informatization, and digital management of the entire blasting process while enhancing real-time interactive collaboration among various units involved in designing, constructing, supervising hydropower stations. The application of this system in slope blasting and excavation projects at Yebatan Hydropower Station demonstrates its effectiveness in carrying out blast designs while improving control efficiency. Consequently, it provides valuable technical support for slope blasting designs during hydropower station excavations.

The impact of fragmentation size and gradation on the stability and permeability of rockfill in hydraulic engineering is of great significance. Accurate prediction of fragmentation size has become a key focus in rock blasting research. In this study, a PSO-BPNN model is developed based on the Backpropagation Neural Networks (BPNN) with optimized network weights and biases using the Particle Swarm Optimization (PSO) algorithm. The model is trained and tested using representative blasting data, and its reliability and applicability are validated through its application in the Hunyuan Pumped Storage Power Station project in Shanxi. Results demonstrate that the PSO-BPNN model exhibits short computation time and high reliability for predicting fragmentation size, with a maximum relative error between the model output and actual average fragmentation size of 6.56%. Therefore, this model demonstrates high predictive accuracy and applicability, providing precise guidance for construction of rock-fill dams at the Hunyuan Pumped Storage Power Station in Shanxi province.