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Accurate prediction of ground vibration caused by blasting has always been a significant issue in the mining industry. Ground vibration caused by blasting is a harmful phenomenon to nearby buildings and should be prevented. In this regard, a new intelligent method for predicting peak particle velocity (PPV) induced by blasting had been developed. Accordingly, 150 sets of data composed of thirteen uncontrollable and controllable indicators are selected as input dependent variables, and the measured PPV is used as the output target for characterizing blast-induced ground vibration. Also, in order to enhance its predictive accuracy, the gray wolf optimization (GWO), whale optimization algorithm (WOA) and Bayesian optimization algorithm (BO) are applied to fine-tune the hyper-parameters of the extreme gradient boosting (XGBoost) model. According to the root mean squared error (RMSE), determination coefficient (R2), the variance accounted for (VAF), and mean absolute error (MAE), the hybrid models GWO-XGBoost, WOA-XGBoost, and BO-XGBoost were verified. Additionally, XGBoost, CatBoost (CatB), Random Forest, and gradient boosting regression (GBR) were also considered and used to compare the multiple hybrid-XGBoost models that have been developed. The values of RMSE, R2, VAF, and MAE obtained from WOA-XGBoost, GWO-XGBoost, and BO-XGBoost models were equal to (3.0538, 0.9757, 97.68, 2.5032), (3.0954, 0.9751, 97.62, 2.5189), and (3.2409, 0.9727, 97.65, 2.5867), respectively. Findings reveal that compared with other machine learning models, the proposed WOA-XGBoost became the most reliable model. These three optimized hybrid models are superior to the GBR model, CatB model, Random Forest model, and the XGBoost model, confirming the ability of the meta-heuristic algorithm to enhance the performance of the PPV model, which can be helpful for mine planners and engineers using advanced supervised machine learning with metaheuristic algorithms for predicting ground vibration caused by explosions.

The worldwide mining industry consumes a vast amount of energy in reduction of fragment size from mining to mineral processing with an extremely low-energy efficiency, particularly in ore crushing and grinding. Regarding such a situation, this article describes the effects of rock fragmentation by blasting on the energy consumption, productivity, minerals’ recovery, operational costs in the whole size reduction chain from mining to mineral processing, and the sustainability of mining industry. The main factors that influence rock fragmentation are analysed such as explosive, initiator, rock, and energy distribution including blast design, and the models for predicting rock fragmentation are briefly introduced. In addition, two important issues—fines and ore blending—are shortly presented. Furthermore, the feasibility of achieving an optimum fragmentation (satisfied by a minimum cost from drilling-blasting to crushing-grinding, maximum ore recovery ratio, high productivity, and minimum negative impact on safety and environment) is analysed. The analysis indicates that this feasibility is high. Finally, the measures and challenges for achieving optimum fragmentation are discussed.HighlightsThe effects of rock fragmentation on the whole size reduction chain from mining to mineral processing are described.The main factors influencing rock fragmentation by blasting are analysed.Main models for predicting rock fragmentation are briefly introduced and commented on.The feasibility, measures, and challenges of achieving optimum fragmentation are analysed.

Research was conducted at the PT. Bukit Asam Air Laya Mine Site. The aim of the blasting activity is to explode the B2-C interburden layer in order to obtain Seam C coal. The drilling pattern used is a staggered pattern with a vertical drilling direction. The actual blasting geometry used is with a burden of 7 m, spacing of 8 m, hole depth of 8 m, stemming of 4 m, and powder column of 4 m. The level of blasting fragmentation for sizes greater than 160 cm based on theoretical calculations is 26.49 %, while the target set by the company for boulder fragmentation is no more than 20%. To reduce the level of fragmentation, changes were made to the actual geometry by conducting studies using the RL Ash, CJ Konya, and ICI Explosive theories. From this study, recommendations for the proposed blasting geometry were obtained with a burden of 6 m, spacing of 9 m, hole depth of 11.66 m, stemming of 5.14 m, and powder column of 6.52 m. With these changes in geometry, fragmentation measuring more than 160 cm was obtained at 17.15%, or it can be said to achieve the fragmentation target of less than 20%.

Pyrotechnic detection has always been one of the critical issues in blasting safety. Due to the complex environment of blasting sites, irregular detonator wire postures, and the differences in object scales, making the detection of pyrotechnics more challenging. To address these challenges, this paper proposes an improved algorithm based on a multi-scale parallel attention mechanism and wavelet-separable convolution, called WA-YOLO. First, we integrate wavelet convolution into depthwise separable convolution and propose a novel convolutional block (WSDConv, Wavelet Separable Depthwise Convolution). This new convolutional block is added to the model’s backbone, improving feature extraction while also lowering computational parameters. Furthermore, we introduce an improved Cross Stage Partial (CSP) structure by combining multi-scale convolutions with a parallel attention mechanism, embedding it into the C2f module of the neck network to improve the model’s ability to detect objects of varying scales in complex backgrounds. To tackle the detection accuracy drop caused by the irregular shapes and varying aspect ratios of detonator wires, the model uses the Wise-IoU loss function. This enhances the model’s generalization and robustness by improving the precision of overlap calculations for bounding boxes. The experimental results show that the improved model achieved an average precision increase of 12.6% on the self-built dataset, particularly with an average precision increase of 8.3% in the detection of detonators. Additionally, the model performance also improved on the VOC2012 dataset, with a recall increase of 1.3% and an average precision increase of 1.6%. These results indicate that the proposed model exhibits strong generalization capabilities, can work effectively across different datasets, and provides an effective solution to the challenges of target detection in blasting environments.

Using the well-known laws of the theory of elasticity and the basic principles of the quasi-static wave hypothesis of the mechanism of destruction of a solid medium by an explosion, methods have been developed for calculating the parameters of drilling and blasting (D&B) for raises advance using the methods of blast-hole and borehole charges. It has been established that the calculating D&B parameters is carried out in the same sequence as when drifting operation. To check the calculating D&B parameters using the new method during raise advance, a numerical simulation of changes in the stress-strain state of a rock mass under the influence of an explosion was carried out. According to the results of numerical simulation, the formation of zones of inelastic deformation in the face of a rising mine working under blast load, uniform grinding of the rock was obtained, which will avoid the release of oversized pieces after the explosion. The developed methodology was tested in the conditions of the “Yuvileina” mine of PJSC “Sukha Balka” during the raise advance of a 1420 m level using a sticked emulsion explosive (EE) Anemix P. Test explosions obtained good results in blasting the face of a raise, uniform crushing of the rock and a high coefficient of use of bore-holes has been established.

In this paper, based on the finite element numerical simulation, the influence of uncoupled charge on rock blasting effect under the condition of water and air is studied. The results show that the stress wave propagation speed of the air medium uncoupled charge is faster, and the stress fluctuation is larger in the early stage of blasting. The water medium uncoupled charge is more effective in energy transfer and crack formation. This shows that the decoupling charge of water medium can improve the energy utilization rate of explosives, reduce the vibration caused by excessive crushing, save the amount of explosives, and enhance the effect of blasting crushing.

This study proposes a fractal damage calculation method that understands the blasting damage laws at the macroscopic, mesoscopic, and microscopic scales of rock. The findings indicated that the binary graph derived from the Moments algorithm can represent minute cracks and exhibit less noise within the image. This makes the algorithm suitable for identifying and extracting macroscopic damage. A three-dimensional (3D) reconstruction technique offers visualization of the macroscopic rock damage following an explosion. The extent of this damage is quantitatively assessed using the box dimension. In addition, a multifractal method is introduced to comprehensively evaluate the macroscopic and mesoscopic damage to rock post-blasting. The multifractal dimension calculations analysis reveals that the mesoscopic damage to rock following blasting is a significant factor in the overall blasting damage. The box dimension presents a straightforward, macroscopic evaluation method for assessing 3D macroscopic fractures. On the other hand, the multifractal dimension can more accurately evaluate the macroscopic cracks and mesoscopic damage resulting from blasting. Both methods emphasize different aspects and are equally effective for assessing blasting damage.HighlightsThis study proposes a fractal damage calculation method that understands the blasting damage laws at the macroscopic, mesoscopic, and microscopic scales of rock.The box dimension is a straightforward macroscopic evaluation method for assessing 3D macroscopic fractures.The multifractal dimension more accurately evaluates the macroscopic cracks and mesoscopic damage from blasting.After ordinary charge initiations, blasting damage exhibited a bimodal distribution along the borehole's axis, peaking in the charging section.

The formation process of blasting craters and blasting fragments is simulated using the continuum-discontinuum element method (CDEM), providing a reference for blasting engineering design. The calculation model of the blasting funnel is established, and the formation and fragmentation effect of the blasting crater under different explosive burial depths and different explosive package masses are numerically simulated. The propagation law of the explosion stress wave and the formation mechanism of the blasting crater are studied, and the relationship between the rock-crushing effect and blasting design parameters is quantitatively evaluated. Comparing the results of numerical simulation with the results of field tests and theoretical calculations indicated that the three are consistent, which proves the accuracy of numerical simulation. The results showed that the area of the blasting crater rises with the increase of explosive package mass and explosive burial depth. Taking the proportion of broken blocks with particle size ranging from 0.01 to 0.1 m as the research object, it can be found that the proportion of broken blocks with an explosive burial depth of 0.62 to 1.12 m is 0.45 to 0.18 times that with an explosive burial depth of 0.5 m. The proportion of broken blocks with an explosive radius of 4 to 12 cm is 1.14 to 3.29 times that with an explosive radius of 2 cm. The quantitative analysis of the blasting effect and blasting design parameters provides guidance for the design of blasting engineering.

The technical-economic efficiency of rock extraction works depends significantly on the drilling and blasting works as well as the adjacent costs. The cost of the explosive is an important component in these and the generalization of the widespread use of the use of bulk explosives (ANFO) has generated a significant reduction in the cost. Making the explosive close to the place of use in fixed or semi-stationary installations on the quarry stage eliminates the costs related to storage or long-term storage, transport, escort, security. However, installations for the manufacture of ANFO type explosives must consistently produce a simple quality explosive mixture. The quality lies in the participation of the precursors as well as in the degree of homogenization, stability and a good behavior to external stimuli that can lead to sensibility to initiation stimuli or inhibition of sensitivity where the harmful influence of moisture in the raw material or environment must be emphasized. The paper presents tests and results obtained in recent years for such installations used by several companies in Romania performed under the supervision of INSEMEX specialists. These assessments were completed with the certification of explosives manufacturing facilities for the specified operating parameters as well as for explosives.

Casualty analysis of major terrorist attacks in recent decades shows an enormous increase in fatalities and economic losses. Due to frequent terrorist attacks and failure of engineering structures under blast load, this issue has gained the attention of scientists and structural engineers. Recently, threat due to explosions is considerably raised owing to the availability of small size explosive devices with powerful and high range explosive materials. Thus, there is an immediate need for the structures, vulnerable to such tragic events, to be analysed and designed to resist these extreme loading conditions. To predict the behavior of structure under explosion loads, blast load analysis needs to be done. The effective blast parameters such as standoff distance, angle of incidence, explosive type and charge weight with its damaging effects discussed by various researchers have been overviewed in the present work. Further, it is uneconomical to harden the structure to resist the blast load. Therefore, certain strategies which can be adapted to mitigate the effect of blast pressure have also been analysed, and discussed different analytical models for prediction of blast loads. The paper present basics of blast for beginner researchers and structural engineers to understand such complex loading scenario.