To address the issues of blurred boundaries, chamfered transitions, irregular geometries, and excessive dependence on empirical judgment in determining blast body model boundaries for 3D digital open-pit blasting design, this study proposes a tiered boundary identification and reconstruction methodology grounded in geometric feature analysis of the blast formations. Firstly, a multi-feature weighted fusion strategy was employed for top surface identification, systematically integrating four key geometric characteristics:normal vector orientation, slope gradient, circularity index, and horizontal alignment. This synergistic multi-criteria validation significantly improved detection precision. Secondly, a two-stage segmentation algorithm incorporating normal-vector alignment principles and spatial connectivity analysis was developed to classify side surfaces as contour faces or free faces. Finally, through the combined application of least-squares fitting, the Alpha Shape algorithm, and arc-length parameterization techniques, critical profile boundaries, including the bench crest line and toe line of the blast body geometry, were accurately reconstructed and mathematically optimized. Based on the above research findings, a boundary recognition system was successfully developed to accurately identify and reconstruct a 3D blast model. Practical validation using operational models from the Changlai mining area demonstrated the system′s stable performance and reliable recognition capabilities. Comparative analysis with manual identification demonstrated a 1.70% area deviation in top-surface recognition, 98% spatial overlap accuracy, a 1.94% bench-face line-length discrepancy, and a 0.56% relative root-mean-square error, confirming the method′s reliability and practical viability. This study contributes novel technical solutions for advancing digital transformation in open-pit blasting design.

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.

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.

The amplification of blasting vibration on rock slopes significantly impacts the accuracy of vibration monitoring and slope safety evaluation. This study investigates the phenomenon through numerical simulation and explores the amplification mechanism based on structural dynamics and vibration mode analysis. The simulation results show that the vibration amplification phenomenon primarily occurs in the vicinity of the bench crest. Influenced by the geometric dimensions of the bench crest and the physical and mechanical parameters of the rock mass, higher peak vibration velocities occur at the bench crest than at the bench toe, due to an increase in platform width, a decrease in bench height, a reduction in the slope ratio and a lower rock mass quality. Conversely, the distribution of the first principal stress exhibits an opposite trend to that of the peak vibration velocity. To improve the accuracy of safety assessments, it is recommended that monitoring points be placed at the bottom line of the bench. The vibration mode analysis further confirms that the amplification effect is predominantly governed by the low-order vibration modes, determined by geometric dimensions and mechanical parameters of the rock mass. The agreement between the mode analysis and numerical simulation results highlights the critical role of low-order vibration modes in controlling the slope's vibration amplification.

Air overpressure generated from the blasting excavation may affect the safety of surrounding structures. The blasting operation area of the horizontal tunnel of the second phase of Meizhou Pumped storage power station is only 81 m away from the steel accident gate of the upper drainage tunnel of the second phase project, which has been built and put into the operation in the first phase. However, the blasting may affect the operation stable of the accident gate. Therefore, taking the blasting excavation of the horizontal hole above the water diversion of the second phase of Meizhou pumped storage power station as the object, the field monitoring of blasting air overpressure was carried out. The distribution rule of blasting air overpressure and its influence on the safety of the emergency gate in the upper reservoir of Meizhou pumped storage power station were analyzed, which provided support for analyzing the influence of blasting air overpressure on the safety of the emergency gate in the upper reservoir. The blasting air overpressure monitoring data show that the air overpressure level in front of the accident gate about 80 m away from the blasting master surface is distributed at 0.63~3.46 kPa, which is much smaller than the suggested corresponding blasting safety control standard of 100 kPa. The protective facilities before the gate can effectively reduce the air overpressure at the gate position, and the measured air overpressure in the fourth and fifth blasting is reduced by more than 55%. When the single and total charge volume are effectively controlled, the measured air overpressure value is much smaller than the suggested control standard value. Besides, there is no abnormality in the field macro investigation and other detection data, the blasting construction does not affect the safe operation of the accident gate on the reservoir.

The blasting construction of water conservancy projects is characterized by its long duration and large scale. However, traditional methods for blasting design and construction control are inadequate to meet the requirements of current water conservancy project development. Therefore, it is crucial to study and establish a platform-based, networked, and intelligent blasting design and control system with significant engineering significance. To achieve this goal, this research adopts a front-end and back-end separation method using the Angular framework and SpringBoot framework based on BIM(Building Information Modeling), WebGIS(Geographic Information System), and developed blasting design software. The system comprises an intelligent blasting design module, three-dimensional visualization module, digital blasting control module, as well as an intelligent safety evaluation and prediction/warning module. This integration enables intelligent blasting design along with comprehensive auditing functions throughout the entire process. Importantly, the system can select control points on the excavation contour line for intelligent blasting design based on actual site conditions. It generates blast design schemes that undergo review using a model parameterized dynamic joint cropping method before being uploaded. This approach promotes standardization, informatization, and digital management of the entire blasting process while enhancing real-time interactive collaboration among various units involved in designing, constructing, supervising hydropower stations. The application of this system in slope blasting and excavation projects at Yebatan Hydropower Station demonstrates its effectiveness in carrying out blast designs while improving control efficiency. Consequently, it provides valuable technical support for slope blasting designs during hydropower station excavations.