Based on the blasting demolition of a 7-storey frame-shear wall structure in Wuhan, this study investigates the impact of different incision patterns on the collapse process. A refined finite element numerical model was established using ABAQUS, with steel and concrete supporting columns modeled separately and the upper collapse body modeled as a whole. This approach enables accurate simulation of the mechanical behavior of supporting columns while improving computational efficiency. A triangular incision form model was also developed and compared against the trapezoidal incision form used in the project. The stress distribution, recoil distance, and collapse motion characteristics of supporting columns under the two different incision forms were analyzed to explore their effects on the collapse process. Results indicate a high consistency between the numerical simulation and the actual collapse regarding timing, motion characteristics, and overall process, validating the modeling approach. Compared to the trapezoidal incision form, the triangular incision form features a lower center of gravity, causing the structure to tilt quickly around the incision vertex post-detonation. This leads to rapid failure of the rear-row support columns under large eccentric pressure. Consequently, the collapsed body makes ground contact faster, at a higher velocity and disintegrates more thoroughly. Additionally, the triangular incision generates greater horizontal kinetic energy, resulting in a larger recoil distance. This analysis highlights the significance of incision form selection in optimizing blasting demolition outcomes.

As a main mean of open-pit mining, bench blasting is still an irreplaceable production method at present and even in the future. By deeply analyzing the measured data of bench blasting and using 3DEC software to simulate the bench blasting process, the internal rock mass movement trajectory and muckpile distribution during the bench blasting process were revealed. The research results show that the monitoring points generally rose along the vertical direction first and then fell during the blasting process. Among them, the movement of the monitoring points on the upper part of the monitoring hole were more obvious in the vertical direction, rising to a certain height and then quickly moving vertically downward. While the monitoring points on the lower part of the monitoring hole mainly moved forward in the horizontal direction, and the vertical direction movement is relatively weak. At the same time, in order to study the spatial distribution of the muckpile, the bench in the research area were divided into six parts, as Ⅰ~Ⅵ. Besides, the main part (0~40 m) of the muckpile was divided into four regions, as A, B, C and D. According to the simulation results, it can be found that the Ⅴ rock mass accounts for the most in region A (muckpile 0~10 m), which is as high as 41.7%. The Ⅰ~Ⅴ rock mass distribution is relatively even in region B (muckpile 11 m~20 m). The Ⅰ~Ⅲ rock mass accounts for 43.1%, 37.5% and 19.3%, respectively, and the Ⅳ rock mass accounts for a very small part in region C (muckpile 21~30 m). It is basically composed of the Ⅰ rock mass in region D (muckpile 31~40 m) at the forefront of the blast muckpile, which accounts for 95%.

Blasting excavation generates transient P-waves that significantly impact tunnel stability. For water-filled diversion tunnels, the dynamic response of the surrounding rock differs from conventional dry tunnels. Most existing analytical studies focus on the steady-state solution and single-lined tunnels, rarely accounting for composite linings or the presence of water. This paper investigates the transient stability response of deep-buried circular composite lining diversion tunnels under transient P-wave disturbances. The fluid within the tunnel is treated as a distinct medium, and the tunnel-lining interface is considered a non-ideal contact surface. By applying Fourier synthesis, wave function expansion, and trapezoidal quadrature formula, an analytical solution is derived. Validation through comparison with existing literature demonstrates the method's effectiveness. The study analyzes the effects of Poisson's ratio of surrounding rock, the non-ideal interface's elastic coefficient, and the disturbance's loading duration on the dynamic stress concentration coefficient. Results indicate that the compressive stress concentrations occur at the roof and floor, while tensile counterpart concentrations appear at the two sidewalls during dynamic disturbance. As Poisson's ratio increases, there is a transition from tensile to compressive stress concentration, with a gradual degree in compressive stress intensity. Poor contact between the rock mass and liner induces oscillations in the stress time-history curve. The dynamic response converges accordingly as the elastic coefficients of an imperfect interface approach those of a perfect interface. With increasing blasting load duration, peak dynamic stress around the roof and floor initially rises, then stabilizes, while stress at the sidewalls initially decreases before leveling off.

To explore the influence of ignition position change on overpressure characteristics of methane/air premixed explosion under different equivalence ratios, several tests with varying length-to-diameter and equivalence ratios on the rise rate of peak overpressure and positive pressure duration were carried out through a self-built explosion test system. The main influencing factors affecting the pressurization characteristics of methane/air premixed explosion were analyzed by the dimensional analysis method, and the calculation formulas of rise rate of overpressure peak and positive pressure during methane/air premixed explosion were proposed. The results show that the rise rate of the overpressure peak increases with the increase of the equivalence ratio, and the increase in length-to-diameter ratio makes the rise rate decrease gradually, which is different from the attenuation rate. The positive pressure duration is gradually prolonged with the rise of the length-to-diameter ratio. However, the maximum positive pressure duration corresponds to different equivalence ratios with the length-to-diameter ratio changes. Furthermore, the calculation formulas of the rise rate of overpressure peak and positive pressure duration of methane/air premixed explosion are obtained by the dimensional analysis method, and the feasibility of the formulas is verified by comparing the experimental values with the theoretical values. It was found that methane/air premixed explosion is significantly affected by the ignition position and equivalence ratio, which can provide a reference for the power evaluation and safety control of methane explosions.

To enhance the accuracy of blasting vibration predictions in an open-pit mine stripping project, a new peak particle velocity (PPV) prediction formula is proposed, incorporating geological elevation differences and slope effects. Based on the principles of dimensional analysis, the traditional Sadovsky formula was modified by introducing the elevation difference (H) and slope coefficient (γ), resulting in a new prediction model (Formula 11). Notably, when H=0, the new formula reverts to the traditional Sadovsky formula, ensuring its reliability. A field vibration monitoring test was conducted in the mine, with 5 monitoring points at elevation differences of 0.222 m, 0.176 m, 0.865 m, 1.617 m, and 2.465 m. Using the TC-4850 blasting vibration meter, vibration data were recorded, and multiple predictions, including the Sadovsky and the newly proposed formula, were fitted using multivariate nonlinear regression. Results show that the proposed formula achieves the highest correlation coefficient (R²=0.905), surpassing other models. Furthermore, the new formula exhibits improved prediction accuracy, with a maximum relative error of 20.85% and an average error of 8.11%, compared to 24.89% and 10.31% for the original Sadovsky formula. By considering the factors of elevation and slope, the proposed prediction formula significantly improves the precision of PPV predictions under complex terrain conditions, providing a scientific basis for blasting vibration control and safety management. Applying the specific scheme and data proves the effectiveness and practicality of the formula.

Pre-split blasting has emerged as a crucial technique for enhancing the permeability of low-permeability coal seams and improving gas drainage efficiency. While extensive research has focused on the effects of factors such as blast hole configuration, charge structure, charge coefficient, explosive quantity, and the propagation dynamics of blasting stress waves, limited attention has been given to fracture expansion characteristics through numerical simulations. Furthermore, experimental investigations into crack propagation remain scarce. This study addresses these gaps by examining low-permeability coal samples from a specific mine, employing small-dose coupled charge blasting technology combined with computerized tomography scanning technology. The experimental approach enabled the acquisition of macroscopic damage characteristics and three-dimensional crack distribution patterns post-blasting, facilitating an in-depth analysis of internal crack expansion under blasting stress. Key findings demonstrate the feasibility of utilizing detonating explosives instead of conventional explosives for small-scale coal sample blasting experiments with low-dose coupled charges. The results reveal that: (1) a larger blast hole diameter correlates with diminished crack propagation and permeability enhancement under constant charge quantity and tamping pressure; (2) tamped charges outperform loose charges when blast hole diameter and charge quantity are held constant; (3) an optimal charge quantity exists for fracture propagation, with excessive amounts proving counterproductive. Specifically, for the standard-sized low-permeability coal samples examined, a charge quantity of 25 mg yielded optimal results, producing a crack volume ratio of 12.79% and a single crack volume of 20 135.03 mm, followed closely by a 20 mg charge.

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.

Since the concept of intelligent blasting was proposed, the on-site mixed explosive vehicles (MEVs) have struggled to meet the evolving demands of the field. Reviewing the development of MEVs abroad reveals that while developed countries have a higher proportion of on-site mixed explosives usage, their levels of automation and intelligence have progressed slowly, with only a handful of civil explosive giants proposing related concepts. In China, to meet the national requirements for intelligent mine construction, some civil explosive enterprises and MEV manufacturers have begun exploring intelligent upgrades and applications for MEVs, achieving notable technological breakthroughs. China Gezhouba Group Explosive Co., Ltd. has developed an intelligent on-site mixed ANFO vehicle featuring precise borehole positioning, automatic blasting design acquisition, one-button charging, and automatic information collection. This article introduces this intelligent ANFO vehicle, detailing its key technologies: high-precision charging metering control systems, intelligent high-precision positioning, and smart loading systems. These advancements offer references for the intelligent development of similar explosive vehicles. The future direction for on-site MEVs is to achieve full intelligence and crewless operation, encompassing capabilities such as unmanned driving, automatic hole targeting, and smart charging. Ultimately, these vehicles aim to integrate seamlessly into the framework of safe and collaborative operations within the mining sector.

A novel energy dissipation blasting technique based on water coupling is proposed to explore new methods for rapid excavation of spillway protection layers in hydropower stations under relatively intact hard rock conditions. This method specifically addresses the excavation requirements of the Nam Kong 1 Hydropower Station spillway in Laos. By increasing borehole pressure, the technique generates stronger stress, which is advantageous for excavating hard rock formations. Simulation analysis using LS-DYNA software demonstrates that coupling water-charged explosives with a blocked borehole bottom amplifies the peak load on the borehole walls and extends the explosive load duration, thereby improving the fragmentation of harder rock at the borehole bottom. Results indicate that the combination of bottom-hole blockage and water-coupled charges increases lateral damage depth and prolongs load application time, thus achieving more effective excavation and formation in relatively intact hard rock. Comprehensive evaluations based on numerical simulations and field test parameters confirm that this approach significantly improves the quality of excavation and formation of the first-stage stilling basin floor in practical engineering applications.

Safety management plays a vital role in blasting operations, and blasting safety is closely related to the processes of drilling, blasting, loading, transportation, and dumping, with significant interactions among these procedures. However, due to the diverse sources and complex structure of current blasting safety data, the lack of systematic integration poses challenges for on-site personnel to accurately acquire critical safety knowledge under complex working conditions. To address this issue, this study applies a BERT-BiLSTM-CRF-based method for entity recognition in the field of blasting safety management. The BERT pre-trained model is first used to obtain dynamic word embeddings, followed by optimal label sequence tagging using the BiLSTM-CRF model. A knowledge graph covering seven entity types and nine relationship types is constructed and stored using the open-source Neo4j graph database system. Experimental results show that the F₁-score for all entity types exceeds 60%, demonstrating that the proposed model significantly improves entity recognition accuracy compared to traditional models. Based on this, a knowledge graph-based Q&A system for blasting process safety management in open-pit coal mines is developed, enabling rapid querying of domain knowledge and efficient matching of various blasting processes with safety standards. With the support of this Q&A system, on-site engineers can make timely and informed decisions in complex blasting safety management scenarios.