Blasting Engineering is a core course in urban underground engineering and mining engineering in universities, and teaching blasting experiments is an indispensable link in practical teaching. As explosive engineering has a characteristic of great danger, the traditional explosive engineering experiment construction is rugged enough to be carried out indoors, which inconveniences teaching. Therefore, more and more schools rely on virtual simulation platforms. According to the teaching idea and demand of explosive engineering virtual simulation, this paper builds a virtual simulation teaching platform for blasting experiment teaching. Unity3D, a development tool for virtual simulation systems, was utilized to ensure high compatibility when running on different platforms. Meanwhile, the 3DS Max and Maya were applied to build and improve a realistic model. Furthermore, problems like slow loading speed and non-realistic animation through the cloud rendering technology were solved. The software ANSYS was used to simulate the propagation mechanism of blasting vibration waves in different rock layers better to reflect the blasting vibration waves in practical engineering. Finally, the wave field cloud map was saved as a snapshot in the virtual simulation system, and virtual simulation experiments of blasting vibration were carried out. The practice and application results show that the virtual simulation experiment platform can enable students to participate in the experiments of explosive engineering independently and deeply and improve students' experimental experience and practical innovation ability.

To investigate the energy evolution and failure patterns of magnetite during blasting and to minimize the impact of blasting disturbances on the stability of pillars and surrounding rocks, a series of multi-stage strength impact tests were conducted on magnetite samples using a Split Hopkinson pressure bar (SHPB) apparatus. The dynamic response characteristics of magnetite were analyzed, focusing on parameters such as dynamic peak compressive strength, failure modes, fragmentation size, and energy dissipation density under varying strain rates. The results show that magnetite's dynamic peak compressive strength and energy dissipation density increase exponentially with the increase in strain rate. At the same time, the crushing size decreases exponentially, demonstrating a strong strain-rate dependency. The failure process of magnetite can be divided into three stages: crack compaction, elastic deformation, and crushing. The dynamic increase factor (DIF) also increases with the increase in strain rate. The failure mode of magnetite transitions from splitting failure at lower strain rates to crushing failure at higher strain rates as crack interactions intensify. Therefore, when blasting rock breaking is applied to magnetite mining, it is crucial to balance impact strength and energy dissipation to enhance crushing efficiency while meeting the required fragmentation standards.

Pre-splitting blasting has been widely employed in river channel slope excavation to effectively mitigate damage to the retained rock mass, reduce blast-induced vibrations, and optimize blasting parameters for water-saturated slopes. Investigation of reasonable parameters for pre-splitting blasting in such conditions is important for river channel excavation projects. Based on geometric, physical, and dynamic similarity principles, an experimental model for pre-splitting blasting water-saturated slopes was designed, utilizing concrete as a substitute for red sandstone and detonators instead of emulsified explosives. The quality of pre-split crack formation, slope face shaping, and retained rock mass damage were evaluated under various conditions. The results showed that the pre-split crack formation quality and slope shaping quality significantly improved. The damage to the retained rock mass was reduced by 24.86% when the hole diameter increased from 0.8 cm to 1.2 cm. Field test results indicated that the optimal blasting effect can be achieved with a pre-split hole diameter of 115 mm and a hole spacing of 80 cm in a practical application of pre-splitting blasting for water-saturated slopes when the geological conditions involve medium-hard rocks.

Given the current lack of comprehensive research on the mechanism of rock fracturing by high-pressure gas, this study draws upon the research method used to determine peak pressure at the borehole wall in the drilling and blasting method. By analyzing the complete rock fracturing process through the liquid oxygen expansion method, a calculation model for the peak pressure at the borehole wall was derived from the shock tube theory, considering the changes in the rock medium and uncoupling coefficient. Using a dynamic strain tester, a concrete model experiment was conducted to measure the peak pressure at the borehole. Under fixed conditions of a 60 mm expansion tube diameter and four different apertures (75~120 mm), the peak pressure was measured. The test results show that, with the same liquid oxygen equivalent and rock medium conditions, the time to peak pressure increases linearly with the uncoupling coefficient, following the relationship t=230.6k-127.85. As the uncoupling coefficient increases, the peak pressure at the borehole wall decreases gradually, with the attenuation rate gradually slowing. A comparison between the experimental results with the theoretical calculations shows a similar trend in peak pressure attenuation with the uncoupling coefficient, confirming the reliability of the theoretical model.

The original stope benches of Dahuangshan Open-pit Mine were in disarray, with pumice between benchs and steep slope conditions. Following blasting operations, a crushing system was introduced to improve rock fragmentation efficiency, significantly increasing potential safety risks near high and steep slopes. This study researched safe blasting techniques and protective measures for slopes in open-pit mines to ensure slope safety during blasting construction. Active protection methods were proposed, including limiting instantaneous charge to 200 kg, aligning the blasting direction parallel to the slope, and preserving approximately 5 m of rock wall along the slope edge. Protective infrastructure was enhanced by installing two protective nets on a cleaning platform mid-slope, excavating a 7 m-deep and 20 m-wide stone protection ditch at the foot of the slope, building a 2 m-high stone protection wall using crushed stones outside of the ditch, and erecting a 2 m-high isolation net outside the protection wall. These safety measures were complemented by auxiliary monitoring methods to enhance the safety of blasting operations and protect the crushing system. Field inspections confirmed that the construction methods effectively ensured the stability of the high-steep slopes and minimized risks during blasting.

The occurrence of oversized fragments during blasting operations significantly increases the cost of blasting, crushing, and hauling expenses. This study addressed the slab' phenomenon observed in the blasting of intact hard rock at the Pingtanyuan Pumped Storage Power Station, where the oversized fragments of the surface blasting area was up to 6 m×5 m×2.5 m. Through comprehensive mechanism analysis, the investigation indicated that the quality of the stemming was the key reason for forming large fragments at the upper part. Meanwhile, the mechanism of its influence lies in the over-long stemming length of the original blasting scheme, which resulted in a low charge center, leading to insufficient energy distribution at the top of the blast hole. Furthermore, an oversized blasting fragments control measurement based on stemming quality optimization was proposed. The stemming length was optimized from 3~4 m to 2.1~2.4 m using a time-sharing piecewise calculation method and the optimization principle, which allowed the part of the stemming structure to rush out of the blast hole. Besides, the decontaminated rock chips were used as stemming material. The results show that the optimized scheme prevented the occurrence of the slab phenomenon, significantly reduced boulder rates, and saved rock breakage costs.

Underwater blasting vibration poses significant challenges in mining engineering applications, particularly channel dredging, seaport, and bridge construction. This study investigates the vibration attenuation mechanism and propagation characteristics through damping borehole configurations. The attenuation law of underwater blasting damping holes was studied, and a comprehensive experimental program to analyze the blasting vibration signals and piezoelectric signals was conducted by comparing three scenarios: conventional blasting without damping measures, water-coupled damping holes, and air-coupled damping holes. The optimized borehole parameters included a 2 cm diameter, 5 cm spacing, 4 cm row spacing, and 17 cm depth, positioned 20 cm from the explosive source. Experimental results demonstrated that using underwater blasting damping holes can effectively reduce the peak vibration velocity of blasting. The average damping rate of water-coupled damping holes and air-coupled damping holes is 17.5% and 27.2%, respectively. Time domain analysis revealed a consistent correlation between piezoelectric signals and the peak vibration velocity. The damping mechanism primarily affected vertical vibration components, with effectiveness positively correlated with charge weight. Field validation tests confirmed an 18.1% vibration reduction, establishing the practical efficacy of the proposed damping borehole array.

Reinforced concrete structures are usually subjected to explosion impact load, resulting in severe damage. Different protective materials are typically laid on reinforced concrete slabs to improve the explosion resistance. The experimental study on the explosion resistance of reinforced concrete slabs with different protective materials was conducted using the drop hammer test, and an accelerometer tested the impact of reinforced concrete. An embedded piezoelectric intelligent aggregate is used to monitor the internal damage signal of a reinforced concrete slab under the drop hammer impact load. The test results show that both carbon fiber reinforced matrix composites (CFRP) and polyurea can effectively protect the specimens in the single-layer reinforced structure, with an average decrease of 78.20% and 79.05% relative to reinforced concrete acceleration and 40.98% and 65.79% peak impact stress, respectively. Additionally, the average acceleration reduction of polyurea-concrete-CFRP (IPC), polyurea-CFRP-concrete (ICP), and CFRP-concrete-polyurea (CIP) compared with reinforced concrete slabs are 70.29%, 77.46% and 79.85% in the composite protective structure, respectively. The average peak impact stress reduction is 32.73%, 56.32%, and 51.07%, respectively, which can effectively protect the specimens and improve the impact resistance of concrete slabs. It can provide a reference for related engineering applications.

A large-area concrete site was prepared to eliminate the boundary effects to investigate the propagation law of detonation-induced cracks in differential blasting under varying hole spacing. Multiple sets of linear three-hole and cross-five-hole model tests were conducted using electronic detonators and detonating cords as the blasting sources. The propagation length, direction, and crack arrest position of detonation cracks were recorded under different blasting parameters. The key factors affecting crack propagation were identified by combining the experimental results with the theory of sequential controlled blasting. The results indicate that in the three-hole model, a through-crack forms between the blast holes when the middle hole detonates first, followed by the two side holes. However, as the hole distance increases, the crack becomes increasingly irregular. When the distance reaches 25 times the hole diameter, the crack fails to penetrate and no longer propagates along the direction of the blast holes. In the cross five-hole model, a through-crack can only form when the spacing is within 20 times the hole diameter. The crack generated by the first blast tends to propagate towards the nearest subsequent hole. Still, it does not follow a straight path, exhibiting deflection due to the influence of the additional holes. Therefore, to achieve straight cracks along the contour surface in practical engineering, it is crucial to adjust the timing and control blasting parameters based on specific hydrogeological conditions to fully utilize the void effect and the detonation timing difference.

During aero-engine casing containment tests, the explosive separation method used to achieve the constant-speed fly-off of titanium alloy blades often produces a bright titanium fire phenomenon. This titanium fire obstructs high-speed camera recording of the blade fly-off process. To address this issue, this study analyzed the mechanism of titanium fire generation and proposed a barrier layer method to suppress titanium fire during shaped energy cutting of titanium alloys. Numerical simulations using the Euler algorithm in AUTODYN were conducted to evaluate the blocking effect of the barrier layer and its feasibility for titanium fire suppression. Experimental investigations were then performed to quantitatively assess the brightness reduction of titanium fire, comparing the effectiveness of four barrier materials. The results indicate that 0.1mm thick aluminum and titanium tin foil achieve titanium fire suppression rates of 29.5% and 24%, respectively, demonstrating moderate effectiveness. A 0.1 mm thick copper sheet shows poor performance with a suppression rate of only 4.3%, while a 0.1 mm thick aluminum silicate coating exhibits the best performance, achieving a suppression rate of 70.9%. This study has summarized the mechanism of titanium fire suppression suing barrier layers during shaped energy cutting of titanium alloy plates and validated the feasibility of the barrier layer method. The findings can provide a practical approach for titanium fire elimination in explosion separation processes involving shaped energy cutting of titanium alloys.