This paper aims to explore the development of a risk management system for engineering blasting to achieve systematic management of quality, safety, environmental, and occupational health risks throughout the entire life cycle, encompassing all aspects and elements of blasting activities. Based on the establishment of comprehensive safety and environmental awareness, it advocates the use of systems engineering methodology to analyze risks in the field of engineering blasting in depth. The article follows the internationally accepted ISO 9001(Quality Management System), ISO 45001(Occupational Health and Safety Management System), and ISO 14001(Environmental Management System) standards, and constructs a scientific risk management framework. It is proposed to combine technical means, such as standards, metrology, inspection and testing, certification, and accreditation, with a risk management model for engineering blasting systems based on the PDCA (PLAN-DO-CHECK-ACT) cycle. This model emphasizes prevention as its primary focus, and through improvement, it ensures that risks are within a controllable range. The article further introduces digital twin technology, and constructs the engineering blasting B-NQI (B-NQI risk-based digital integration of engineering blasting quality, safety, environment and occupational health) system, which realizes real-time monitoring, prediction, control and decision of risk information, greatly improving the efficiency and accuracy of risk management of engineering blasting system. The research not only enriches the theoretical framework of engineering blasting risk management but also provides practical tools and methods for industry applications. Constructing the B-NQI system helps reduce various risks in the engineering blasting process, ensures project progress, and provides strong protection for worker safety and environmental protection.

Differences in thickness, mineral composition, wave impedance, and joint fissures. This often leads to a mismatch between the charge structure of the pre-splitting and cutting holes and the physical and mechanical properties of the layers, which can easily cause the complex rock layers to fail to pre-split. The soft rock layers form chicken-nest-shaped explosive pits due to excessive consumption of explosive energy, making it difficult for pre-splitting and cutting holes to penetrate the entire length of the blast hole effectively. To attain consistent pre-splitting of the composite roof, the LS-DYNA software was employed to analyze the impact of the charging structure on the pre-splitting effect of the composite roof. Based on this foundation, a uniform-dispersion and pressure-holding pre-splitting blasting technique was proposed for the composite roof. Field experiments were conducted, and in conjunction with the preliminary evaluation of the progression of post-blast fractures, the viability of this uniform-dispersion and pressure-holding pre-splitting blasting method was substantiated. The research results indicate that the escape of explosive gas from hard rock layers to soft rock layers is the primary reason for the uneven energy utilization in the pre-cracking explosion of the composite roof. The composite roof uniform dispersion pressure pre-splitting blasting technology divides the pre-splitting holes into multiple chambers according to the layered structure of the composite roof. Each layer has an independent post-explosion pressure holding chamber, which meets the explosive energy requirements of each pre-splitting layer, thereby avoiding excessive consumption of explosive energy in soft rock layers and enhancing the pre-splitting effect in hard rock layers.

In the reconstruction and expansion projects of expressways, a large number of cross-line bridges cannot meet the development needs of modern transportation and are facing demolition and reconstruction. Traditional manual and mechanical demolition methods have drawbacks, including low efficiency, prolonged timelines, and substantial traffic interference. In contrast, blasting demolition-with its inherent benefits of safety, economic viability, and operational efficiency has emerged as the optimal technique for dismantling cross-line bridges on expressways. Based on the reconstruction and expansion project of the section from the Hubei-Henan boundary to Junshan on the Beijing-Hong Kong-Macao Expressway, one-time combined blasting demolition was carried out on five cross-line bridges in the K1018+990~K1048+550 section. Through the quantitative design, fine construction, and multidimensional protection of four types of bridges-such as equal-section catenary hingeless arch bridges, inclined-leg rigid frame bridges, half-through arch bridges, and steel frame arch bridges-the goal of safe and efficient blasting demolition was realized. The practical results show that the collapse mode and disintegration effect of the bridge can be effectively controlled by reasonably designing the blasting cut and initiation sequence. The distributed cooperative detonation system, based on radio communication, overcomes the spatiotemporal coordination problem of synchronously detonating group bridges over a long interval. The protection measures of ‘covered protection+near body protection’ were adopted to control the splash of individual flying debris effectively. The ‘rigid support layer+elastic buffer layer’ protection system effectively prevents the impact damage of the bridge collapse on the high-speed pavement. The engineering practices presented herein demonstrate that through meticulous design, synchronized control strategies, and multi-tiered protective measures, the safe and efficient demolition of cross-line bridge groups across extensive expressway sections in complex environments can be accomplished.

A study was conducted using explosive cutting cords to titanium alloy plates to quantitatively investigate the additional kinetic energy generated during blade fracture in aviation engine case inclusion experiments. The additional kinetic energy was analyzed through both computational and experimental approaches. Using AUTODYN software, two computational methods were employed: the center-of-mass motion method (yielding E1) and the particle-by-particle accumulation method (yielding E2). The accuracy of these methods was systematically compared. Experimental validation was achieved by measuring the additional kinetic energy (E3) in controlled explosion experiments. The computational results were verified against experimental data, confirming the reliability of both the simulation and testing methodologies. The study reveals that the maximum additional kinetic energy generated during the severance of titanium alloy plates constitutes a smaller proportion of the total kinetic energy proportion than the threshold proposed by the FAA company. These findings provide critical insights for designing and evaluating cartridge inclusion experiments in aviation safety applications.

To enhance the mechanical performance of recycled aggregate concrete (RAC) under dynamic loading, this study systematically investigates the synergistic effects of polyvinyl alcohol (PVA) fiber reinforcement and recycled coarse aggregate (RCA) replacement on the dynamic mechanical performance of RAC through split Hopkinson pressure bar (SHPB) impact compression tests. Thirty-six specimen groups with varying PVA fiber dosages (0%, 0.1%, 0.3%) and RCA replacement ratios (30%, 40%, 50%) were designed to elucidate the damage mechanisms and enhancement mechanisms of PVA fiber-reinforced recycled aggregate concrete (PVA-RAC) under impact loading, utilizing comprehensive analyses of dynamic stress-strain curves, failure patterns, and dynamic increase factors (DIF). The results demonstrate that PVA fibers significantly suppress crack propagation via bridging effects, thereby altering the material's failure mode from brittle fragmentation to ductile cracking. Both dynamic peak stress and DIF exhibit substantial improvements with increasing fiber content and strain rate. While higher RCA replacement ratios (40%~50%) diminish compressive strength due to the inherent porosity of RCA, their heterogeneous interfacial properties promote energy dissipation through complex crack propagation paths, thereby partially mitigating strength losses. This study establishes a theoretical framework for the dynamic design and application of PVA-RAC in seismic-resistant protective structures. Furthermore, it pioneers a synergistic approach to integrating construction waste recycling with the development of high-performance recycled building materials. The findings have both theoretical innovation and practical engineering significance.

To systematically reveal the influence of laws of microwave radiation parameters (power, time) on the degradation of the mechanical properties of iron ore and the energy dissipation mechanism, and to improve the crushing efficiency of iron ore, this iron ore from Sishanling in Liaoning Province is the research object. By adopting a method combining microwave pretreatment, multi-scale mechanical tests, and microscopic tests, this thesis conducts static and dynamic impact tests as well as XRD tests on iron ore samples under different microwave actions. By analyzing the mechanical properties of iron ore subjected to various microwave treatments and utilizing the principles of energy conservation, this study elucidates the damage evolution characteristics and the laws governing energy evolution of iron ore under the coupled action of microwave and mechanical forces. The research results show that: (1) With an increase in microwave power and irradiation time, the sample mass decreases slightly, and the longitudinal wave velocity, uniaxial compressive strength, and elastic modulus exhibit a linear degradation trend. Microscopic tests have confirmed that the damage is caused by thermal stress cracking, rather than a change in composition. (2) The analysis of energy evolution indicates that microwave pretreatment diminishes the total input energy density of the sample, reduces the proportion of elastic energy, and elevates the proportion of dissipated energy. This phenomenon suggests a deterioration in the ore's storage capacity and a transition toward plastic yielding. (3) Dynamic impact tests show that an increase in microwave damage leads to a 45.58% increase in reflected energy, a 16.12% decrease in transmitted energy, and an increase in energy dissipation to 37.49%.

To further investigate the influence of surrounding rock mass damage on the rock burst mechanism, material selection for simulating the damage zone was carried out, and a test piece containing the damage zone (1000 mm×600 mm×400 mm) was fabricated. Using the self-developed rock burst model test system's drilling device, caverns were excavated in the specimens (with a hole diameter of 110 mm). Rock burst model tests were then conducted on specimens with varying damage zone thickness through step loading, considering the damage effects on the surrounding rock. During the tests, cameras monitored the damage process of the tunnel wall. Image expansion was performed based on the rubber paper model principle, and the box dimension of the expanded image was calculated and analyzed. The results show that the macro-failure process of a rock burst consists of crack initiation, particle ejection, crack propagation, and debris avalanche stages. As the thickness of the damage zone increases, the failure depth of the specimen chamber's side wall gradually increases. In the stage of slow increase and sharp increase in the box dimension of the left and right tunnel walls, the growth rate of the box dimension decreases linearly with the increasing thickness of the damage zone. With the increase in damaged zone thickness, cracks in the tunnel wall primarily concentrate within the damaged zone during loading, and the damage depth of the tunnel wall increases when the cavity is damaged. The findings further elucidate the breeding and failure mechanism of rock bursts in deep-buried caverns under the condition of surrounding rock damage.

Accurate acquisition of blasting vibration signals is essential for analyzing the harmful effects of blasting operations. However, geological conditions, electromagnetic interference, and instrument errors can introduce significant high-frequency noise into the collected signals, leading to distortion and inaccurate data interpretation. To address this issue, a signal decomposition algorithm based on Ospley Optimization Algorithm (OOA) is proposed to optimize Variational Mode Decomposition (VMD). Multiscale Permutation Entropy (MPE) is also employed to construct a noise reduction model for tunnel blasting vibration signals. OOA is iteratively applied to determine the optimal VMD parameters (K & α) and obtain the intrinsic mode formula (IMF) using the maximum information coefficient as the fitness function. The MPE values of each decomposed signal are then used to identify the noise components, which are removed to reconstruct the denoised signal. This coupled algorithm was applied to analyze the blasting effects in Dashan Tunnel, Yunnan Province. The results demonstrate that the proposed optimization algorithm effectively decomposes the signal and eliminates noise without significantly affecting the low-frequency energy. The OOA-VMD denoising method's performance is superior to the complete ensemble empirical mode decomposition (CEEMD) and conventional VMD algorithm, thereby verifying its reliability.

This study explored the influence of high-pressure gas blasting on coal's crack propagation and vibration characteristics. Using independently developed high-pressure air blasting devices, the high-pressure air blasting experiments were carried out on the simulated coal specimens. The surface crack propagation speed and particle vibration of the specimen were measured using a blasting speed acquisition instrument and a blasting vibration acquisition instrument, respectively. Furthermore, the crack propagation and fracture induced by high-pressure air blasting and the variation characteristics of particle vibration energy were analyzed. Scanning electron microscopy (SEM) was used to examine the evolution of pore cracks in specimens before and after blasting. The experimental results indicate that the surface cracks on the specimen are induced to develop and propagate along the direction of confining pressure loading at a design pressure of 15 MPa, and the crack development and propagation speed is v_{Bi-directional unequal pressure} > v_{no confining pressure} > v_{Bi-directional equal pressure}. Besides, The crack development and propagation speed vary under different confining pressure conditions, exhibiting two stages: rapid development and steady-state development as the distance from the crack initiation hole increases. The induced particle vibration signal is distributed in the range of 0~250 Hz, with the energy in the main frequency band of the vibration signal significantly different from that in other sub-bands and the vibration main frequency band significantly differing from other sub-bands. The primary vibration signal is concentrated in the low-frequency band of 0~31.25 Hz. These findings provide a theoretical basis and guidance for optimizing the distribution of fractures induced by high-pressure gas blasting and improving the effectiveness of gas extraction.

To investigate the effects of decked charge structure on the energy transfer and blasting outcomes, a study was conducted to improve the energy utilization rate of explosives and enhance the blasting impact based on the blasting operations of a limestone mine in Chenzhou. Combining LS-DYNA numerical simulations with on-site optimization experiments, this research examined the rock stress distribution across different charge structures during bench blasting. Simulations were performed on four charge structures: continuous charge, 0.6 m deck, 1.0 m deck, and 1.5 m deck, with effective stress monitored at key points. Field optimization experiments were then conducted using a novel transmissible explosive deck to analyze the overall blasting performance of the blast pile. The research results indicate that the rock damage extent and average maximum effective stress reach peak values at a 1.0 m deck length, resulting in favorable fragmentation. In field tests, the decked charge reduced the powder factor from 0.199 kg/t to 0.179 kg/t, lowered the fine ore rate by 6.54%, reduced the oversize rate by 3.7%, and increased the average block size by 5 cm. This approach minimized energy wastage and resolved uneven fragmentation issues with mixed emulsion explosives, enhancing the mine's economic efficiency.