Ore crushing is a crucial phase in hard rock mining and mineral resource recovery, significantly focusing on optimizing the energy consumption balance between blasting and mechanical crushing. This study analyzed industrial test data from an iron mine to explore the relationship between parent rock size distribution characteristics and mechanical crushing energy sensitivity, providing a theoretical foundation for process optimization and energy efficiency improvement. Initially, the connection between the key parameters of the parent rock size distribution curve and crushing power consumption was investigated. Subsequently, the maximum block size under the screen (D75) was identified as a sensitive indicator for crushing power consumption through correlation analysis. Finally, a theoretical model based on shared blasting control was developed, utilizing an optimal parent rock size distribution curve, R=1−exp[−(X282.1)1.69] to control the block size. Field application of this model demonstrates a cost reduction of 17.63%, affirming its potential for enhancing energy management and cost efficiency in mining operations.

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.

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.

During drilling and blasting of open-pit mining in high and cold regions, water inrush or freezing often occurs on the borehole inside. This phenomenon creates a decoupled charge structure with water and ice, affecting the blasting effect and the rock-breaking mechanism under decoupled conditions. To determine the geometric parameters of the blasting crater and analyze the blasting effect under three types of decoupling medium in the high-cold area, a series of tests were conducted on the blasting effects of different decoupling charges in the Karma open-pit mining in Tibet. Based on the Livingston curve fitting results, the blasting parameters were optimized and applied to on-site engineering blasting. The results indicated significant differences between the visible volumes of the blasting crater and the crushed funnel at burial depths of 1.09~1.49 m. However, these volumes resembled burial depths of 1.49~1.69 m. Compared to the air-deck decoupling, the peak particle velocities under water and ice decoupling were reduced by 25.33% and 11.24%, respectively. The critical charge depths varied among the three decoupling materials, with water decoupling having the most significant critical depth, ice decoupling charge, and air-deck decoupling having the shallowest. The charge weights required for water and ice decoupling and ice decoupling were 18.9% less than those for air-deck decoupling. In multi-hole bench blasting, the explosive factor for water and ice decoupling was reduced by 18.2% compared to air-deck decoupling, and the rate of large fragments decreased from 8.9% to 4.3%. This indicated that water and ice decoupling charges made the energy distribution of explosives more uniform.

To investigate the fracture toughness of natural slate under dynamic loading, dynamic impact tests were conducted on notched semi-circular bending slate specimens by a 50 mm diameter split Hopkinson pressure bar testing system and the crack growth process was recorded by the high-speed cameras. Furthermore, the dynamic fracture toughness and crack propagation rate of slate under different impact pressure and prefabricated crack lengths were studied. The results show that the dynamic fracture toughness of the specimen is positively correlated with the impact pressure and loading rate, and the dynamic fracture toughness first increases and then decreases with the rise of the prefabricated crack length. According to the fitting results, the dynamic fracture toughness of the specimen reaches the maximum value when the prefab crack length is 7.45 mm. The maximum values of dynamic fracture toughness at 0.2, 0.3 and 0.4 MPa were 2.99, 3.57 and 4.14 GPa·m1/2, respectively. The failure process of the specimen can be divided into five stages: dynamic damage, crack propagation, crack formation, crack propagation, and specimen fracture. The propagation speed of the main crack of the specimen greatly fluctuates, while the prefabricated crack length has little effect on the propagation velocity of the specimen. The study revealed the differences in dynamic fracture behavior of slate specimens under different working conditions.

A reasonable blasting construction method is critical to maintaining caverns' stability and water-sealing integrity. In this study, seismic wave detection and acoustic wave detection were conducted within a water-sealed cavern. The HHT signal analysis method was used to process the seismic wave signals generated by blasting, and both Empirical Mode Decomposition (EMD) and Ensemble Empirical Mode Decomposition (EEMD) were applied to compare and reduce signal mode aliasing, improving the accuracy of signal analysis. The marginal spectrum, instantaneous energy spectrum, three-dimensional energy spectrum, and loose zones in surrounding rock were used to evaluate the influence of different blasting schemes on the water-sealed caverns. The results show that the EEMD-Hilbert analysis method effectively mitigates mode aliasing issues caused by traditional EMD decomposition, producing a smoother and more reliable vibration velocity time-history curve. Marginal spectrum analysis of the reconstructed signal reveals that the frequency band of the double-sided wall heading method ranges from 200 to 380 Hz. In contrast, the frequency band of the single-sided wall guide pit method is narrower, concentrated between 110 and 250 Hz, with relatively lower frequency energy in both conditions. The combined instantaneous energy of the double-sided wall guide method is higher than that of the single-sided wall guide method, with 41.67% and 23.73% of the total instantaneous energy concentrated in the first section of the cutting hole for each method, respectively. The instantaneous energy distribution of the single-sided wall guide method is more uniform and lower than that of the double-sided. The range of loosening rings on both sides of the arch waist in the double-sided wall heading method is about 1.0 to 1.2 m. In contrast, the single-sided wall guide pit method measured 0.8 meters and 1.0 to 1.2 meters on the expanding excavation surface and guide tunnel surface, respectively. A joint analysis of the EEMD Hilbert method and acoustic detection indicates that the single-sided wall guide pit method is more suitable for blasting excavation in water-sealed caverns.

The resistance line, as a core parameter in a blast design, is closely related to rock throwing distance and fragmentation degree, thereby directly affecting the fragmentation effectiveness and the final shape of the blast pile. Due to the significant complexity of an underwater blasting project, the factors affecting the effect of underwater blasting are intricate and complex, so it is essential to explore the impact of resistance line parameters on underwater bench blasting law through both drilling and blasting tests and numerical simulations using the FLUENT-EDEM coupling method. Four resistance line cases (2 cm, 4 cm, 5 cm, and 6.5 cm) were tested. The results indicate that as the resistance line parameter increases, the proportion of adequate energy used for rock fragmentation increases, resulting in a larger blasting funnel volume. However, with further increases in the resistance line, the explosive energy per unit volume of rock decreases, and the stress wave reflection intensity weakens. Consequently, the inhomogeneity of blasting block size first decreases and then increases with the resistance line. Additionally, numerical calculations effectively replicate the model test blasting effects, demonstrating that using the FLUENT-EDEM fluid-solid coupling method to study underwater bench blasting fragmentation is practical and feasible.

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.

Drilling and blasting is still the most efficient way to explore deep phosphate mine excavation and mining. There is a severe constraint on the efficiency of phosphate mine digging as its level remained at 70 to 80 meters every month for many years. Therefore, the ore rock blastability classification is critical for the deep phosphate mine working face. The longitudinal wave velocity tests of the rock body in an underground phosphate mine in Yichang, Hubei Province, and measurements of physical and mechanical properties such as rock density, uniaxial compressive strength and tensile strength were carried out. The rock density, uniaxial compressive strength, tensile strength, and rock integrity coefficient were obtained for four types of rocks, namely, dolomitic striped phosphorite, dense striped phosphorite, argillaceous striped phosphorite, and carbon-bearing argillaceous dolomite. To complete the deep phosphorite workings of the mine rock blastability classification, a BP neural network model was established by stochastic functions to generate a large number of learning and testing samples using the Matlab neural network toolbox as taking the pre-measured rock density, uniaxial compressive strength, tensile strength and rock integrity coefficients as inputs and the rock blastability classification as outputs. The grading results show that dolomite-banded phosphorite and mud-banded phosphorite are moderately blastable, and dense-banded phosphorite and carbonaceous mud dolomite are difficult to blast. According to the classification results, the blasting parameters of the stope can be optimized to enhance the blasting effect, reduce the single consumption and the bulk rate of explosives, and improve the safety and economic benefits of deep phosphate mining.

In constructing shield tunnels in a sea area, large-sized boulders and bedrock are often encountered, necessitating pretreatment via blasting. The effectiveness of blasting pretreatment is crucial for the regular excavation of shield machines. Based on Xiamen Metro Line 2 project, a refined blasting pretreatment method for boulders and bedrock in shield tunnels under the sea area is proposed. The method comprehensively considers overburden conditions, blasting fragmentation indexes, and marine biological safety standards. Specific steps include designing blasting parameters, calculating powder factor, determining single-hole charges and average block size, designing charge structures and initiation networks, predicting the distribution of blasting fragments, and optimizing the blasting program to minimize ecological impact. Field application results indicate that post-blasting fragment sizes are within 30 cm, meeting the size requirements for the shield machine. The shield machine could excavate smoothly through the blasting pretreatment section, with excavation parameters similar to those in regular sections. The proposed method achieved a refined, ecological, efficient and safe blasting construction in the sea section containing boulders and bedrock.

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.

Taking the construction of Shikui Road Station to Labor Park Station of Dalian Metro Line 5 as the background, a delicate blasting design was used to control the influence of interval tunnel construction on adjacent buildings. In order to prevent the risk of settlement of adjacent bridge piles, a deep hole pre-reinforcement method of non-shrinkage double-liquid grouting (WSS) was used on the tunnel face. The blasting parameters of the tunnel face were optimized, and a detailed blasting design was given by combining with the step sequence of the tunnel construction method (step method and CRD method). The right line utilized the step method, while the left employed the CRD method. The upper bench of the step method and the upper left chamber 1 of the CRD method were blasted twice: initial cutting blasting to create an empty surface followed by secondary blasting to reduce vibration. The unit consumption of explosives in the cutting part was 1.87~2.33 kg/m3 and 0.40~0.80 kg/m3 in other sections, with the Ms-15 nonel detonator used for maximum section control. In addition, the blasting vibration attenuation law formula was inverted through blasting vibration monitoring, facilitating a pre-check for safety. Furthermore, a numerical simulation using the SPH method was conducted for cutting blasting near side-piercing bridge piles with a single-stage charge of 0.30 kg. The response of the bridge pile located 5 m from the detonation point and subjected to explosive load was analyzed. The blasting operation in this area had been completed, and the piers were safe and sound, indicating that the construction scheme for the side-crossing bridge pile section was feasible. Additionally, the stress wave propagation in strata and bridge piles was simulated, showing speeds of 3280 to 3590 meters per second in bridge piles, and an average speed of 1620 meters per second in rock and soil layers. The propagation speed in bridge piles was significantly higher than in the weathered and clay layers. The SPH method proved effective for large-scale particle calculations without requiring supercomputing power for explosives and adjacent rocks.

To investigate the influence of different blast incision central angles and heights on a cooling tower's overall collapse effect, the structure's collapse process was simulated by ANSYS/LS-DYNA finite element software. The original model was modified to explore the effects of various blasting incision's central angles and heights. Five different blasting incision heights (14 m, 15 m, 16 m, 17 m, 18 m) and three blasting incision central angles (190°, 210°, 230°) were selected for orthogonal combination to analyze their impact on the collapse effect. The results indicate that the blasting incision's central angle significantly influences the distribution range of the collapse debris, while the blasting incision height plays a secondary role. The highest point of the pile is generally located along the collapse centerline and near the transverse fracture of the tower wall. The degree of fragmentation and location of fissures on the rear tower wall determine the height and location of the highest point of the debris pile. At a fixed blasting incision height, the vertical touchdown velocity of the structure decreases as the incision's central angle increases. Conversely, at a fixed incision central angle, the vertical touchdown velocity decreases and then increases with increasing incision height. The optimal demolition parameters for the cooling tower are a blasting incision angle of 210° and a blasting incision height of 17 m.

This study addresses the blasting demolition of an 18-story oval frame-core tube structure. Systematic analysis revealed that the structure's small height-width ratio and long span contribute to potential instability and collapse, with uneven stress distribution due to irregular shear wall placement within the core tube. To mitigate these challenges, delayed blasting and auxiliary weakening techniques were employed. The approach included pre-treatments such as splitting and cutting to transform the cylindrical structure into a wall-like form, reducing deviation during collapse. The building was divided into four blasting zones with increasing delay times, particularly extending the delay for the last two zones by 1 second to ensure sequential support point failure and prevent incomplete collapse. Additionally, the upper and lower double-incision folding blasting method was utilized to control vibration upon ground impact and enhance overall dissociation. The demolition process, lasting approximately 5 seconds, resulted in the building collapsing primarily along the designed direction with minimal backseat movement and evident structural failures. The sequential floor folding and concentrated pile blasting demonstrated effective demolition.

Stainless steel 06Cr18Ni11Ti and cast steel 20Mn explosive welding composite plates can be used to build bridges in high alpine areas. Two groups of different welding parameters were used to investigate the weld interface characteristics of stainless steel 06Cr18Ni11Ti and cast steel 20Mn. The explosive thickness was 30 mm, the detonation velocity was 2300 m/s, and the stand-off distances were 4 mm and 10 mm, respectively. The morphology of the weld interface was studied using an optical microscope and scanning electron microscope, and the samples were submitted to tensile and flexural testing and hardness tests. Furthermore, the fracture morphology of the weld material was studied using a scanning electron microscope. In the interfacial morphology examination, the sample with a 10 mm stand-off distance had a thicker melting layer than the sample with a 4 mm stand-off distance. The melting layer thickens as the contact corrugation increases. Corrosion was observed on the cast steel 20Mn side of the weld interface enriched with austenite. The 4 mm stand-off samples did not exhibit apparent twins, whereas the 10 mm ones did. The 10 mm stand-off samples had higher interfacial deposition energy and strain rate, making twins more likely to occur. Tensile test findings indicated that all fracture separations occurred on the cast steel's 20Mn side. The shear strength of sample 1 ranged from 383.6 to 394.1 MPa, while that of sample 2 ranged from 394.3 to 408.4 MPa, showing binding strength across the interface greater than that of 20Mn. Both 10mm and 4 mm stand-off samples exhibited ductile fracture. In the 90 bending test, the welded interface shows no delamination or cracks, indicating outstanding bending performance. The hardness test results indicate that the hardness of cast steel 20Mn and stainless steel 06Cr18Ni11Ti after explosive welding are higher than that of the corresponding raw materials. Approaching the weld interface, the hardness increases noticeably. The maximum hardness for samples with a 4 mm stand-off is 413.2 HV, while for samples with a 10 mm stand-off, it is 407.9 HV. Work hardening is more pronounced on the 20Mn side of the sample with a 10 mm stand-off. The effect of hardening is much more noticeable. The fractures of the samples with 4 mm and 10 mm stand-offs display a river-like form in the fracture morphology study.

With the rapid advancement of modern industry, the demand for high-performance materials has grown significantly. Titanium/duplex stainless steel composite plates, known for their exceptional corrosion resistance, demonstrate vast potential for diverse applications. In this study, a bimetallic composite plate comprising TP270C titanium alloy and SUS821L1 high-strength duplex stainless steel was fabricated using explosive welding. The microstructural characteristics of the composite plate interface were thoroughly investigated through metallographic microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). Additionally, the welding quality was systematically evaluated. The results showed that the welded interface exhibited an intermediate structure between flat and wavy when the interface deposition energy was low. In contrast, the welded interface displayed a wavy structure at higher interface deposition energy. Element diffusion and grain refinement were observed in the regions adjacent to both interfaces. Complete recrystallization predominated in the welded interface, molten zone, and adiabatic shear band. Near the welded interface, titanium underwent partial recrystallization, while duplex stainless steel exhibited a combination of partial recrystallization and deformed grains. Localized thermal accumulation facilitated grain growth in the molten layer, whereas titanium particles encapsulated within the molten layer exhibited refined grain structures. Mechanical performance tests indicated that the sample with higher interface deposition energy achieved a 40.33% increase in shear strength and a 4.52% improvement in bending strength compared to the sample with lower interface deposition energy.

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 vBi-directional unequal pressure > vno confining pressure > vBi-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.

As rock-breaking technology advances, the limitations of traditional explosive methods are increasingly evident. The liquid oxygen energy storage method, a new non-explosive technique, presents an uncertain blasting mechanism and scientific challenges that must be addressed. Field vibration tests were conducted to analyze the variation trends and the decay characteristics of peak vibration velocities in particles to further characterize the liquid oxygen energy storage rock-breaking blasts and address the challenges of applying empirical methods on-site. Additionally, indoor small-scale blasting experiments were performed to identify key parameters for small liquid oxygen charges. The experimental results reveal that the liquid oxygen energy storage effectively fractures rocks while maintaining low dust and noise levels. Peak particle vibration velocities at 3 m, 6 m, and 10 m under single blast conditions were 3.04, 1.24, and 0.62 cm/s, respectively. The small-scale charge tests reveal that for the liquid oxygen charge to detonate successfully and effectively fracture the rock, appropriate inflation time and pressure are required to prevent detonation and other issues. Increased inflation time and pressure lead to more significant adsorption of liquid oxygen by the charge's absorbent, facilitating saturation and enhancing detonation probability. Overall, the liquid oxygen energy storage method stands out due to its low vibration, environmental friendliness, and non-polluting nature, marking a significant potential advancement in engineering blasting.

Smooth blasting is generally used to control tunnel formation, which requires managing the density of the line charge. Conventionally, air-spaced axial uncoupled charges are used and connected by detonating cords. However, detonating cords require a large amount, are expensive and difficult to approve, and cannot achieve uniform dispersion of charges. Currently, bottom-concentrated charging structures are used without using detonating cords in the surrounding holes of tunnel excavation, leading to serious over-excavation and under-excavation. To address this issue, a new type of energy-gathering tube has been designed. This new tube combines a PVC half tube and energy-gathering cover with a fixed ring, enabling precise control of explosive amounts, simplifying the charging process, and ensuring the stability of the entire device. It is not limited by the water environment, providing efficient energy transmission and effectively controlling tunnel over-excavation and under-excavation. To evaluate the blasting effect of the new energy-gathering tube, it was first verified through a sacrificial explosion test. The test showed that with the new tube, multiple sections of the detonated explosive can be stably transmitted at 30 cm intervals with a dosage of 60 g. Numerical simulations also demonstrated the good cutting effect of the new tube. This new energy-gathering tube was applied in the Dongshan Tunnel of the Fenyang Shilou Expressway, achieving smooth blasting without detonating cords with a line charge density of 200 g/m and a half-hole trace rate of 90%, effectively reducing over-excavation and under-excavation.

The impact of blasting vibration on surrounding buildings has been widely concerned. Based on the deep hole bench blasting project of Changtan Open-pit Coal Mine, the characteristics of the adjacent 11-story frame-shear structure office building are comprehensively analyzed. After several blasting vibration tests, the distribution characteristics of vibration velocity and main frequency in different directions were analyzed. The significance of elevation difference on vibration velocity in various directions was obtained through single-factor analysis. Finally, based on the dimensional analysis method, a vibration velocity prediction model under the influence of multiple factors was studied, proposed, and applied to the blasting safety charge design. The main conclusions are as follows: with the increase of floors, the primary vibration direction changes from horizontal radial (X) to horizontal tangential (Y), and finally to vertical (Z). In most working conditions, the PPVx and PPVy are not more than 0.17 cm/s and 0.213 cm/s, respectively, and the elevation has little influence. The PPVz is concentrated in 0.05~0.41 cm/s, and the elevation amplification effect is significant in 7~11 layers. The maximum charge per delay, total charge amount, and horizontal distance are substantial for the three-axis PPVs. The elevation difference is not significant for the PPVx but significant for the PPVy and PPVz. The main vibration frequency is concentrated in 3~12 Hz, and some reach 16~30 Hz. Based on the vibration prediction model for the office building, combined with the blasting safety regulations and the blasting parameters under the most dangerous working conditions, the total charge of the bottom blasting should be within 10 267 kg, and the total charge of the deep hole bench blasting should be between 8268~8883 kg.

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 & ) 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.

Studying the dynamic response and failure mechanism of hazardous substances storage cabinet structures under internal combustible gas explosion loads can minimize the consequences of explosion accidents, reducing casualties and property losses, which holds significant engineering and social value. This study used methane mixed with air as the combustible gas in internal explosion tests conducted within a hazardous substances storage cabinet structure. Tests were performed under four gas cloud conditions: 1 m3, 8 m3, 27 m3 and 78 m3. Typical overpressure and displacement time-history curves from internal explosion were obtained, and the dynamic response was analyzed. The results show that the displacement response of the storage cabinet structure synchronized with the load response. As the overpressure load increased, the displacement of the storage cabinet wall increased accordingly, reaching their peak nearly simultaneously. The results of overpressure and structural response tests indicate that the peak value of the overpressure load measured in the test did not follow the expected trend, as the more extensive gas volume did not consistently result in higher peak overpressure values.

Measurement acceptance plays a crucial supervisory and guiding role in mining engineering. However, traditional blasting acceptance processes and methods in underground mines are insufficient to meet modern production needs and affect the efficiency and quality of underground mining. To address this issue, the Yanqianshan Iron Mine -213 m level roadway was studied to explore a new measurement and acceptance method based on a high-precision laser SLAM (Simultaneous Localization and Mapping) algorithm. By obtaining point cloud data of the roadway before and after underground mine excavation, the foundation for subsequent data analysis and processing was established. In the data processing phase, methods such as point cloud denoising, ICP (Iterative Closest Point) registration, point cloud segmentation, and slicing were employed to create comprehensive measurement and acceptance processes for underground mining engineering. Point cloud denoising effectively removes noise and enhances data purity and credibility. The ICP registration method ensures precise alignment of point clouds through iterative optimization, maintaining high data consistency. Point cloud segmentation and slicing techniques offer practical solutions for accurately calculating irregular explosion volumes. The research results demonstrate that this high-precision laser SLAM measurement acceptance method improves work quality and efficiency. It ensures construction quality in underground mining and provides critical technical support for optimizing underground blasting designs.