Search Results (417)

Underground blasting vibrations are a critical factor influencing the stability of mine slopes. However, existing studies have yet to establish a quantitative relationship or clarify the underlying mechanisms linking blasting-induced vibrations and slope deformation. Taking the Shilu Iron Mine as a case study, this research develops a dynamic mechanical response model of slope stability that accounts for blasting loads. By integrating slope radar remote sensing data and applying the Pearson correlation coefficient, this study quantitatively evaluates—for the first time—the correlation between underground blasting activity and slope surface deformation. The results reveal that blasting vibrations are characterized by typical short-duration, high-amplitude pulse patterns, with horizontal shear stress identified as the primary trigger for slope shear failure. Both elevation and lithological conditions significantly influence the intensity of vibration responses: high-elevation areas and structurally loose rock masses exhibit greater dynamic sensitivity. A pronounced lag effect in slope deformation was observed following blasting, with cumulative displacements increasing by 10.13% and 34.06% at one and six hours post-blasting, respectively, showing a progressive intensification over time. Mechanistically, the impact of blasting on slope stability operates through three interrelated processes: abrupt perturbations in the stress environment, stress redistribution due to rock mass deformation, and the long-term accumulation of fatigue-induced damage. This integrated approach provides new insights into slope behavior under blasting disturbances and offers valuable guidance for slope stability assessment and hazard mitigation. Full article

Background: Rock–blast design is a canonical inverse problem that joins elastodynamic partial differential equations (PDEs), fracture mechanics, and stochastic heterogeneity. Objective: Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, a systematic review of mathematical methods for geomechanically informed blast modelling and optimisation is provided. Methods: A Scopus–Web of Science search (2000–2025) retrieved 2415 records; semantic filtering and expert screening reduced the corpus to 97 studies. Topic modelling with Bidirectional Encoder Representations from Transformers Topic (BERTOPIC) and bibliometrics organised them into (i) finite-element and finite–discrete element simulations, including arbitrary Lagrangian–Eulerian (ALE) formulations; (ii) geomechanics-enhanced empirical laws; and (iii) machine-learning surrogates and multi-objective optimisers. Results: High-fidelity simulations delimit blast-induced damage with ≤0.2 m mean absolute error; extensions of the Kuznetsov–Ram equation cut median-size mean absolute percentage error (MAPE) from 27% to 15%; Gaussian-process and ensemble learners reach a coefficient of determination ($R^2>0.95$) while providing closed-form uncertainty; Pareto optimisers lower peak particle velocity (PPV) by up to 48% without productivity loss. Synthesis: Four themes emerge—surrogate-assisted PDE-constrained optimisation, probabilistic domain adaptation, Bayesian model fusion for digital-twin updating, and entropy-based energy metrics. Conclusions: Persisting challenges in scalable uncertainty quantification, coupled discrete–continuous fracture solvers, and rigorous fusion of physics-informed and data-driven models position blast design as a fertile test bed for advances in applied mathematics, numerical analysis, and machine-learning theory. Full article

This study aims to estimate the carbon footprint and relative uncertainties for design components of conventional and geopolymer concrete. All the design components of alkaline-activated geopolymer concrete, such as fly ash, ground granulated blast furnace slag, sodium hydroxide (NaOH), sodium silicate (Na₂SiO₃), superplasticizer, and others, are assessed to reflect the actual scenarios of the carbon footprint. The conjugate application of the life cycle assessment (LCA) tool SimPro 9.4 and @RISK Monte Carlo simulation justifies the variations in carbon emissions rather than a specific determined value for concrete binders, precursors, and filler materials. A reduction of 43% in carbon emissions has been observed by replacing cement with alkali-activated binders. However, the associative uncertainties of chemical admixtures reveal that even a slight increase may cause significant environmental damage rather than its benefit. Pearson correlations of carbon footprint with three admixtures, namely sodium silicate (r = 0.80), sodium hydroxide (r = 0.52), and superplasticizer (r = 0.19), indicate that the shift from cement to alkaline activation needs additional precaution for excessive use. Therefore, a suitable method of manufacturing chemical activators utilizing renewable energy sources may ensure long-term sustainability. Full article

Blasting is one of the most widely used and cost-effective techniques for rock excavation and fragmentation in open-pit mining, particularly for large-scale operations. However, repeated or poorly controlled blasting can generate excessive ground vibrations that threaten slope stability by causing structural damage, fracturing of the rock mass, and potential failure. Evaluating the effects of blast-induced vibrations is essential to ensure safe and sustainable mining operations. This study investigates the impact of blasting-induced vibrations on slope stability at the Saindak Copper-Gold Open-Pit Mine in Pakistan. A comprehensive dataset was compiled, including field-monitored ground vibration measurements—specifically peak particle velocity (PPV) and key blast design parameters such as spacing (S), burden (B), stemming length (SL), maximum charge per delay (MCPD), and distance from the blast point (D). Geomechanical properties of slope-forming rock units were validated through laboratory testing. Slope stability was analyzed using pseudo-static limit equilibrium methods (LEMs) based on the Mohr–Coulomb failure criterion, employing four approaches: Fellenius, Janbu, Bishop, and Spencer. Pearson and Spearman correlation analyses quantified the influence of blasting parameters on slope behavior, and sensitivity analysis determined the cumulative distribution of slope failure and dynamic response under increasing seismic loads. FoS values were calculated for both east and west pit slopes under static and dynamic conditions. Among all methods, Spencer consistently yielded the highest FoS values. Under static conditions, FoS was 1.502 for the east slope and 1.254 for the west. Under dynamic loading, FoS declined to 1.308 and 1.102, reductions of 12.9% and 11.3%, respectively, as calculated using the Spencer method. The east slope exhibited greater stability due to its gentler angle. Correlation analysis revealed that burden had a significant negative impact (r = −0.81) on stability. Sensitivity analysis showed that stability deteriorates notably when PPV exceeds 10.9 mm/s. Although daily blasting did not critically compromise stability, the west slope showed greater vulnerability, underscoring the need for stricter control of blasting energy to mitigate vibration-induced instability and promote long-term operational sustainability. Full article

Blast-induced polytrauma (BIPT) is a common injury among military personnel exposed to explosive blasts. It is increasingly recognized as a complex, multisystem disorder that extends beyond neurological damage to include systemic metabolic and inflammatory dysfunction. Adipokines, particularly leptin and adiponectin, are hormones secreted by adipose tissue and are emerging as key mediators in the pathophysiology of traumatic brain injuries. Yet, their long-term dynamics following blast exposure remain unclear. This study investigated the temporal profiles of plasma leptin and adiponectin in a longitudinal rat model of BIPT. Adult male Sprague Dawley rats were subjected to either a single (B) or repeated (BB) blast exposure (20 psi) or served as sham controls. Plasma samples were collected at 24 h, 1 month, 6 months, and 12 months post-exposure, and adipokine levels were measured using Enzyme-linked Immunosorbent Assay. Adiponectin levels exhibited a biphasic response: both B and BB groups showed significant early decrease at 24 h and 1 month compared to sham animals, followed by robust elevation at 6 and 12 months, particularly in the repeated blast group. In contrast, leptin levels remained unchanged acutely but rose significantly at 6 and 12 months post-blast, with the BB group again showing the highest levels. These patterns indicate sustained, exposure-dependent dysregulation of adipokine signaling after blast trauma. The study provides the first longitudinal profile of systemic adipokine responses to BIPT, revealing their potential as accessible biomarkers and therapeutic targets. These findings support a model of chronic metabolic and inflammatory imbalance in BIPT and warrant further investigation in human cohorts and mechanistic studies. Full article

This study analyzed the effects of curing and maturation on the formation of shrinkage strain and destructive processes in concrete. Experimental tests were performed on commonly used concrete, class C30/37, with basalt aggregate and blast furnace cement tested: at constant temperature after water curing, at constant temperature without water curing, and under cyclically changing temperature without prior curing. Shrinkage strain was measured for 46 days with an extensometer on 150 × 150 × 600 mm specimens, and the acoustic emission (AE) method was used to monitor microcracks and processes in concrete in real time. The results were compared with the model according to EN 1992-1-1:2023. It was found that this model correctly estimates shrinkage strain for wet-curing concrete, but there are discrepancies for air-dried concrete, regardless of temperature and moisture conditions (constant/variable). Correlation coefficients between shrinkage strain increments and process increments in early-age concrete are proposed. Correlations between shrinkage strain and destructive processes occurring in concrete were confirmed. It was found that by using correlation coefficients, it is possible to estimate internal damage in relation to shrinkage strain. The results indicate the need to develop guidelines for estimating shrinkage strain in non-model environmental conditions and demonstrate the usefulness of the nondestructive AE method in diagnosing early damage, especially in concrete structures exposed to adverse service conditions. Full article

Ammonia is emerging as a promising zero-carbon marine fuel due to its high hydrogen density, low storage pressure, and long-term stability, making it well-suited for supporting sustainable maritime energy systems. However, its adoption introduces serious safety challenges, as its toxic, flammable, and corrosive properties pose greater risks than many other alternative fuels, necessitating rigorous risk assessment and safety management. This study presents a comprehensive investigation of potential ammonia leakage scenarios that may arise during the fuel gas supply process within confined compartments of marine vessels, such as the fuel preparation room and engine room. The simulations were conducted using FLACS-CFD V22.2, a validated computational fluid dynamics tool specialized for flammable gas dispersion and explosion risk analysis in complex geometries. The model enables detailed assessment of gas concentration evolution, toxic exposure zones, and overpressure development under various leakage conditions, providing valuable insights for emergency planning, ventilation design, and structural safety reinforcement in ammonia-fueled ship systems. Prolonged ammonia exposure is driven by three key factors: leakage occurring opposite the main ventilation flow, equipment layout obstructing airflow and causing gas accumulation, and delayed sensor response due to recirculating flow patterns. Simulation results revealed that within 1.675 s of ammonia leakage and ignition, critical impact zones capable of causing fatal injuries or severe structural damage were largely contained within a 10 m radius of the explosion source. However, lower overpressure zones extended much further, with slight damage reaching up to 14.51 m and minor injury risks encompassing the entire fuel preparation room, highlighting a wider threat to crew safety beyond the immediate blast zone. Overall, the study highlights the importance of targeted emergency planning and structural reinforcement to mitigate explosion risks in ammonia-fueled environments. Full article

When deep-buried tunnels are excavated using the drill-and-blast method, the surrounding rock is subjected to combined cyclic blasting loads and excavation-induced stress unloading. Understanding the distribution characteristics of rock damage zones under these conditions is crucial for the design and safety of building-integrated underground structures. This study investigates the relationship between surrounding rock damage and in situ stress conditions through numerical simulation methods. A constitutive model suitable for simulating rock mass damage was developed and implemented in the LS-DYNA (version R12) code via a user-defined material model, with parameters determined using the Hoek–Brown failure criterion. A finite element model was established to analyze surrounding rock damage under cyclic blasting loads, and the model was validated using field data. Simulations were then carried out to explore the evolution of the damage zone under various stress conditions. The results show that with increasing hydrostatic pressure, the extent of the damage zone first decreases and then increases, with blasting-induced damage dominating under lower pressure and unloading-induced shear failure prevailing at higher pressure. When the hydrostatic pressure is less than 20 MPa, the surrounding rock stabilizes at a distance greater than 12.6 m from the tunnel face, whereas at hydrostatic pressures of 30 MPa and 40 MPa, this distance increases to 29.4 m. When the lateral pressure coefficient is low, tensile failure occurs mainly at the vault and floor, while shear failure dominates at the arch waist. As the lateral pressure coefficient increases, the failure mode at the vault shifts from tensile to shear. Additionally, when the horizontal stress perpendicular to the tunnel axis (σ_H) is less than the vertical stress (σ_v), variations in the axial horizontal stress (σ_h) have a significant effect on shear failure. Conversely, when σ_H exceeds σ_v, changes in σ_h have little impact on the extent of rock damage. Full article

This research explores how RC columns respond to blast-induced dynamic effects, with a novel focus on partially submerged scenarios, bridging a gap between air blast and underwater explosion (UNDEX) research. Using advanced finite element modeling in LS-DYNA, the study captures the unique behavior of RC columns under mixed-media conditions, where shockwaves propagate through water and air interfaces. Comprehensive parametric analyses explore the influence of charge size, blast stand-off, and depth of water, revealing distinct dampening mechanisms and structural responses. Key findings include a measurable reduction in peak displacement of partially submerged explosions compared to fully submerged explosions, attributed to the moderating effects of the water–air interface. A total of 60 simulation cases were conducted to systematically analyze partially submerged scenarios, providing robust insights into energy transmission and damage mechanisms. The numerical models, validated against published experimental data by others, demonstrate the accuracy of computational modeling in simulating damage profiles, displacement histories, and energy dissipation trends. This research offers practical implications for designing resilient RC structures in coastal and maritime environments. The results contribute significantly to the field of blast mechanics, advancing our understanding of mixed-media shockwave dynamics and their impact on critical infrastructure. Full article

Magnaporthe oryzae (M. oryzae) is a phytopathogenic fungus that inflicts damage on vital crops, particularly rice. Its asexual reproduction leads to the generation of numerous conidia, which is a critical factor contributing to the prevalence of rice blast disease. However, the molecules regulating the asexual reproduction of M. oryzae are unknown. In our study, to identify the molecules capable of regulating the asexual reproduction of M. oryzae, compositions of the complete medium (CM) were screened. Results showed that acid-hydrolyzed casein (AHC) could remarkably promote conidial production. One M. oryzae conidiation inducer was isolated from AHC using high-performance liquid chromatography (HPLC) under the guidance of bioassay. Its structure was further elucidated as a decapeptide compound (pyroGlu-EQNQEQPIR) by LC-MS/MS, chemical synthesis, and conidium-inducing assays, named M. oryzae conidiation inducer decapeptide (MCIDP). MCIDP could significantly promote the conidiation of M. oryzae and two other filamentous ascomycetes (Botrytis cinerea and Fusarium graminearum). The Mps1 MAPK cascade signaling pathway is crucial for conidiation, and the effect of MCIDP on this pathway was investigated to elucidate the mechanism underlying conidiation enhancement. qRT-PCR analysis demonstrated that MCIDP could remarkably upregulate the gene expression within the Mps1 MAPK cascade signaling pathway, especially the WSC2, WSC3, PKC1, MKK1, MPS1, and MIG1. Furthermore, the ΔMowsc1, ΔMowsc2, ΔMowsc3, and ΔMomid2 mutant strains were constructed. Bioassay results showed that MCIDP failed to promote conidial formation and hyphal growth in these mutant strains. These findings indicate that MCIDP promotes conidiation of M. oryzae by modulating the Mps1 MAPK signaling pathway. Full article

Due to the difficulty of creating directional fractures efficiently and accurately with existing non-explosive rock-breaking methods, a directional fracturing technique utilizing a coal-based solid waste expansive agent, termed the instantaneous expansion with a single fracture (IESF), has been developed. IESF can generate high-pressure gases within 0.05–0.5 s and utilize gas pressure to achieve directional rock fragmentation. The rock-breaking mechanisms under double-borehole conditions of conventional blasting (CB), shaped charge blasting (SCB), and IESF were studied by theoretical analysis, numerical simulation, and in situ test. The gas pressure distribution within directional fractures of IESF was determined, and the crack propagation criterion between double-borehole was established. Numerical simulation results indicated that the stress distribution in CB was random. SCB exhibited tensile stress of −10.89 MPa in the inter-borehole region and −8.33 MPa on the outer-borehole region, while IESF generated −14.47 MPa and −12.62 MPa in the corresponding regions, demonstrating that stresses generated between adjacent boreholes can be superimposed in the inter-hole region. In CB, strain was concentrated along main fractures. SCB exhibited strains of 7 mm and 8 mm in the shaped charge direction, while non-shaped charge directions showed a strain of 1.5 mm. For IESF, strain in the shaped charge direction measured 6 mm, compared to 1 mm in non-shaped charge directions, resulting in superior directional fracture control. In situ test results from Donglin Coal Mine demonstrated that IESF can form superior directional rock-breaking efficacy compared to both CB and SCB, with the average crack rates of 95.5% by IESF higher than 85.0% by SCB. This technique provides a non-explosive method that realizes precise control of the direction of cracks while avoiding the high-risk and high-disturbance problems of explosives blasting. Full article

The roof slab, as a critical component for partitioning the vertical space within RC frame structures, can effectively mitigate the propagation of shock waves and reduce damage levels in adjacent rooms. This study employed finite element (FE) modeling to investigate the vertical propagation of blast waves and roof ejection velocity in RC frames. The model’s reliability was verified by reconstructing internal explosion tests on RC frames and close-in explosion tests on masonry walls. On this basis, two typical single-room RC frame structures that are vertically adjacent were designed, and numerical simulations of the internal explosion were conducted under four explosive equivalents and four venting coefficients. The propagation of shock waves, load characteristics in the vertically adjacent room, and the dynamic response of roof slabs were examined. The results show that shock waves propagated to the vertically adjacent room decreased by approximately two orders of magnitude for peak overpressure and one order of magnitude for impulse due to the obstruction of shock waves by roof slabs, respectively, compared to the source explosion room. For larger venting coefficients, abundant energy was released through the venting openings, making it difficult to form a quasi-static pressure with a long duration inside the source explosion room. In addition to the shock wave, the explosive ejection of roof slabs in the explosion source room will further exacerbate the damage to the vertically adjacent room. Peak overpressure and impulse propagated to the vertically adjacent room were reduced significantly by the increase in the venting coefficient, resulting in an attenuation of structural damage. Finally, empirical models incorporating the venting coefficient were established to characterize the attenuation coefficients of power parameters, demonstrating the predictive capability for peak overpressure, impulse, and roof ejection velocity in both the explosion source room and the vertically adjacent room. Full article

Doors are considered vulnerable to failure in structures when subjected to extreme loads, such as blasts. Consequently, blast-resistant doors are designed to withstand blast pressure in important structures. This study developed a multi-layer Steel, Aluminum Foam, and Steel–Concrete–Steel composite door panel with Energy Absorption Connectors (SAFSCS-EACs) under near and far field blast loading using finite element analysis in LS-DYNA. Three dynamic response modes were observed based on the crushing strength of energy absorption connectors (EACs) for the SAFSCS-EAC composite door under both near and far field blasts. In addition, the membrane stretching phenomena was observed in the face steel plate. The AF shows a local densification in near field blasts and a global densification in far field blasts. For the SCS panel, a punching-like failure and a global flexural failure were observed in near and far field blasts, respectively. AF has a high energy absorption capacity as a first energy absorption layer, while the EAC also effectively dissipates blast energy through the rotation of the plastic hinges of curved steel plates, thereby reducing the damage to the SCS panel and increasing the door’s structural integrity. Moreover, to check the influence of the curved steel plate thickness of EACs and the core concrete thickness, a parametric study was carried out. The results showed that the blast resistance performance of the SAFSCS-EAC composite door could increase by appropriately designing the EAC curved steel plates’ thickness and ensuring that the compression displacement of the EAC under blast is close to its densification displacement. Additionally, increasing concrete thickness can reduce the degree of damage to the steel–concrete–steel composite panel during the blast, but it leads to a reduction in the energy dissipation of the EAC. Full article

In open-pit bench pre-splitting blasting, the interaction of explosion-induced stress waves between blast holes is essential for safeguarding the rear rock mass. This study utilizes the caustic method to examine the propagation velocity of explosion-induced cracks, the stress intensity factor at the crack tip, and the final morphology of cracks between adjacent blast holes with varying delay times. Field pre-splitting blasting experiments were carried out to validate these effects. The experimental results reveal that, for short inter-hole delay times (0–12 μs), a “hook-like” crack intersection zone emerges between blast holes. Changes in delay time influence the patterns of crack propagation, leading to deviations in the propagation direction of cracks in subsequent blast holes due to the combined effects of stress waves and cracks from preceding holes. The fracture mechanism evolves from pure Mode I (tensile) to a mixed Mode I-II (tensile-shear). Vibration signals from the field blasting tests were analyzed using the variational mode decomposition (VMD) method. The findings indicate that optimized inter-hole delay times can reduce peak particle velocity (PPV) by 18.7–23.4% compared to simultaneous initiation, thereby significantly minimizing damage to the rear rock mass, a crucial factor for maintaining slope stability. Full article

In practice, the bending and fracturing of heavy layers is often considered the primary cause of surface damage, leading to significant environmental impacts, whereas heavy layer-type mining-induced earthquakes are frequently overlooked. This study combines theoretical analysis, UDEC numerical simulations, and industrial experiments to investigate the dynamic behavior of heavy layers and the mechanisms through which mining-induced earthquakes trigger surface damage. It aims to demonstrate that heavy layer movement and mining-induced earthquakes cause surface damage and to develop a replicable engineering solution for seismic prevention and subsidence control in heavy layer mining areas. The results reveal that surface damage stems from the synergistic effects of heavy layer fracturing and associated mining-induced earthquakes, where bending subsidence from heavy layer fracturing is the primary driver, and mining-induced earthquakes act as a secondary factor by compressing fragmented rock pores to amplify overlying layer subsidence. Industrial tests at the 7202 working face using deep-hole roof pre-splitting blasting successfully fractured the heavy conglomerate layer, enhanced goaf bulking, and reduced the intensity of layer movement. This intervention significantly decreased the frequency and energy of mining-induced earthquakes, mitigating surface damage. These findings provide a practical framework for the integrated control of mining-induced earthquakes and subsidence in heavy layer environments. Full article