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.

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.

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.

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.

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 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·m^1/2, 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.

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.

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.

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.

The shock wave generated by underwater explosions has a significant destructive impact on the surrounding environment. Therefore, it is crucial to implement bubble curtain protection for blast area safety. This study aims to investigate the influence of the number of bubble curtain layers on attenuating underwater explosion shock waves. An underwater explosion model with free water and varying numbers of bubble curtain layers was established using AUTODYN finite element software. Through experimental validation of the numerical model, a formula for calculating peak overpressure of the shock wave was derived, and the impact of different numbers of bubble curtain layers on shock wave attenuation in water was compared. The results demonstrate that employing a bubble curtain can effectively reduce peak overpressure from an underwater blast shock wave, achieving an attenuation ratio as high as 83%. Furthermore, increasing the number of bubble curtain layers can further enhance this attenuation effect, reaching more than 94% reduction in peak overpressure. Specifically, when comparing two-layered and one-layered bubble curtains at a distance of 12 m from the detonation center behind the bubble curtain, there is a reduction in peak overpressure by 61.94%. Similarly, using a three-layered bubble curtain leads to an additional decrease in peak overpressure at this distance by 11.38% compared to using a two-layered one. However, when utilizing four-layered curtains instead of three-layers ones, there is only a marginal decrease in peak overpressure (6.42%) at this same distance. In conclusion, implementing a bubble curtain significantly weakens shock waves within water bodies during explosive events. Moreover, fewer layers within the bubble curtain result in greater attenuation effects. However, diminishing returns are observed with each subsequent increase in layer count.