Characteristics of deformation and damage of surrounding rock along the top roadway in the working face of an isolated island and its evolution law.

This study investigates the deformation and damage characteristics of the surrounding rock along the top return mining roadway of an isolated island working face at different stages and reveals its damage mechanism and evolution law. Utilizing a mine in Yangquan City, Shanxi Province, China, as the engineering background, this research employs FLAC 3D numerical simulation and on-site measurements. The findings suggest that the evolution of the plastic zone along the top roadway of the 15,106 island face is largely similar during both the excavation and mining periods. The plastic zones on either side of the roadway are expanding asymmetrically and gradually merging into the plastic zone of the coal pillar. In the destructive stage, the sub-gangs of the roadway are penetrated, indicating the progression into the plastic zone. The investigation points to extensive damage on the larger side of the roadway, the development of fissures, and the significant depth of damage as primary causes of roadway deformation. Moreover, the extent of the plastic zones on both sides of the roadway correlates positively with their relative distance. Continuous monitoring reveals an ongoing increase in roadway displacement, consistent with general observations in coal mining. The results provide valuable insights for optimizing support structures in similar mining environments.

Turbulent blood flow in a cerebral artery with an aneurysm.

Unruptured intracranial aneurysms are common in the general population, and many uncertainties remain when predicting rupture risks and treatment outcomes. One of the cutting-edge tools used to investigate this condition is computational fluid dynamics (CFD). However, CFD is not yet mature enough to guide the clinical management of this disease. In addition, recent studies have reported significant flow instabilities when refined numerical methods are used. Questions remain as to how to properly simulate and evaluate this flow, and whether these instabilities are really turbulence. The purpose of the present study is to evaluate the impact of the simulation setup on the results and investigate the occurrence of turbulence in a cerebral artery with an aneurysm. For this purpose, direct numerical simulations were performed with up to 200 cardiac cycles and with data sampling rates of up to 100,000 times per cardiac cycle. Through phase-averaging or triple decomposition, the contributions of turbulence and of laminar pulsatile waves to the velocity, pressure and wall shear stress fluctuations were distinguished. For example, the commonly used oscillatory shear index was found to be closely related to the laminar waves introduced at the inlet, rather than turbulence. The turbulence energy cascade was evaluated through energy spectrum estimates, revealing that, despite the low flow rates and Reynolds number, the flow is turbulent near the aneurysm. Phase-averaging was shown to be an approach that can help researchers better understand this flow, although the results are highly dependent on simulation setup and post-processing choices.

In silico model of stent performance in multi-layered artery using 2-way fluid-structure interaction: Influence of boundary conditions and vessel length.

BACKGROUND AND OBJECTIVE: Atherosclerotic lesions of coronary arteries (stenosis) are caused by the buildup of lipids and blood-borne substances within the artery wall. Their qualitative and rapid assessment is still a challenging task. The primary therapy for this pathology involves implanting coronary stents, which help to restore the blood flow in atherosclerosis-prone arteries. In-stent restenosis is a stenting-procedure complication detected in about 10-40% of patients. A numerical study using 2-way fluid-structure interaction (FSI) assesses the stenting procedure quality and can decrease the number of negative post-operative results. Nevertheless, boundary conditions (BCs) used in simulation play a crucial role in implementation of an adequate computational analysis. METHODS: Three CoCr stents designs were modelled with the suggested approach. A multi-layer structure describing the artery and plaque with anisotropic hyperelastic mechanical properties was adopted in this study. Two kinds of boundary conditions for a solid domain were examined - fixed support (FS) and remote displacement (RD) - to assess their impact on the hemodynamic parameters to predict restenosis. Additionally, the influence of artery elongation (short-artery model vs. long-artery model) on numerical results with the FS boundary condition was analyzed. RESULTS: The comparison of FS and RD boundary conditions demonstrated that the variation of hemodynamic parameters values did not exceed 2%. The analysis of short-artery and long-artery models revealed that the difference in hemodynamic parameters was less than 5.1%, and in most cases, it did not exceed 2.5%. The RD boundary conditions were found to reduce the computation time by up to 1.7-2.0 times compared to FS. Simple stent model was shown to be susceptible to restenosis development, with maximum WSS values equal to 183 Pa, compared to much lower values for other two stents. CONCLUSIONS: The study revealed that the stent design significantly affected the hemodynamic parameters as restenosis predictors. Moreover, the stress-strain state of the system artery-plaque-stent also depends on a proper choice of boundary conditions.

Fabrication, characterization and numerical validation of a novel thin-wall hydrogel vessel model for cardiovascular research based on a patient-specific stenotic carotid artery bifurcation.

In vitro vascular models, primarily made of silicone, have been utilized for decades for studying hemodynamics and supporting the development of implants for catheter-based treatments of diseases such as stenoses and aneurysms. Hydrogels have emerged as prominent materials in tissue-engineering applications, offering distinct advantages over silicone models for fabricating vascular models owing to their viscoelasticity, low friction, and tunable mechanical properties. Our study evaluated the feasibility of fabricating thin-wall, anatomical vessel models made of polyvinyl alcohol hydrogel (PVA-H) based on a patient-specific carotid artery bifurcation using a combination of 3D printing and molding technologies. The model's geometry, elastic modulus, volumetric compliance, and diameter distensibility were characterized experimentally and numerically simulated. Moreover, a comparison with silicone models with the same anatomy was performed. A PVA-H vessel model was integrated into a mock circulatory loop for a preliminary ultrasound-based assessment of fluid dynamics. The vascular model's geometry was successfully replicated, and the elastic moduli amounted to 0.31 ± 0.007 MPa and 0.29 ± 0.007 MPa for PVA-H and silicone, respectively. Both materials exhibited nearly identical volumetric compliance (0.346 and 0.342% mmHg-1), which was higher compared to numerical simulation (0.248 and 0.290% mmHg-1). The diameter distensibility ranged from 0.09 to 0.20% mmHg-1 in the experiments and between 0.10 and 0.18% mmHg-1 in the numerical model at different positions along the vessel model, highlighting the influence of vessel geometry on local deformation. In conclusion, our study presents a method and provides insights into the manufacturing and mechanical characterization of hydrogel-based thin-wall vessel models, potentially allowing for a combination of fluid dynamics and tissue engineering studies in future cardio- and neurovascular research.

The relation between aortic morphology and transcatheter aortic heart valve thrombosis: Particle tracing and platelet activation in larger aortic roots with and without neo-sinus.

Transcatheter aortic heart valve thrombosis (THVT) affects long-term valve durability, transvalvular pressure gradient and leaflet mobility. In this study, we conduct high-fidelity fluid-structure interaction simulations to perform Lagrangian particle tracing in a generic model with larger aortic diameters (THVT model) with and without neo-sinus which is compared to a model of unaffected TAVI patients (control model). Platelet activation indices are computed for each particle to assess the risk of thrombus formation induced by high shear stresses followed by flow stagnation. Particle tracing indicates that fewer particles contribute to sinus washout of the THVT model with and without neo-sinus compared to the control model (-34.9%/-34.1%). Stagnating particles in the native sinus of the THVT model show higher platelet activation indices than for the control model (+39.6% without neo-sinus, +45.3% with neo-sinus). Highest activation indices are present for particles stagnating in the neo-sinus of the larger aorta representing THVT patients (+80.2% compared to control). This fluid-structure interaction (FSI) study suggests that larger aortas lead to less efficient sinus washout in combination with higher risk of platelet activation among stagnating particles, especially within the neo-sinus. This could explain (a) a higher occurrence of thrombus formation in transcatheter valves compared to surgical valves without neo-sinus and (b) the neo-sinus as the prevalent region for thrombi in TAV. Pre-procedural identification of larger aortic roots could contribute to better risk assessment of patients and improved selection of a patient-specific anti-coagulation therapy.

Integrated monitoring and prediction of thermal discharge from nuclear power plants using satellite, UAV, and numerical simulation.

Global nuclear power is surging ahead in its quest for global carbon neutrality, eyeing an anticipated installed capacity of 436 GW for coastal nuclear power plants by 2040. As these plants operate, they emit substantial amounts of warm water into the ocean, known as thermal discharge, to regulate the temperature of their nuclear reactors. This discharge has the potential to elevate the temperature of the surrounding seawater, potentially influencing the marine ecosystem in the discharge vicinity. Therefore, our study area is on the Qinshan and Jinqimen Nuclear Power Plants in China, employing a blend of Landsat 8/9, and unmanned aerial vehicle (UAV) imagery to gather sea surface temperature (SST) data. In situ measurements validate the temperature data procured through remote sensing. Leveraging these SST observations alongside hydrodynamic and meteorological data from field measurements, we input them into the MIKE 3 model to prognosticate the three-dimensional (3D) spatial distribution and temperature elevation resulting from thermal discharge. The findings reveal that (1) satellite remote sensing can instantly acquire the horizontal distribution of thermal discharge, but with a spatial resolution much lower than that of UAV. The spatial resolution of UAV is higher, but the imaging efficiency of UAV is only 1/40,000 of that of satellite remote sensing. (2) Numerical simulation models can predict the 3D spatial distribution of thermal discharge. Although UAV and satellite remote sensing cannot directly obtain the 3D spatial distribution of thermal discharge, using remotely sensed SST as the temperature field input for the MIKE 3 model can reduce the quantity of measured temperature data and lower the cost of numerical simulation. (3) In the process of monitoring and predicting the thermal discharge of nuclear power plants, achieving an effective balance between monitoring accuracy and cost can be realized by comprehensively considering the advantages and costs of satellite, UAV, and numerical simulation technologies.

Study on Bottom Distributed Bragg Reflector Radius and Electric Aperture Radius on Performance Characteristics of GaN-Based Vertical-Cavity Surface-Emitting Laser.

This article presents the results of a numerical analysis of a nitride-based vertical-cavity surface-emitting laser (VCSEL). The analyzed laser features an upper mirror composed of a monolithic high-contrast grating (MHCG) and a dielectric bottom mirror made of SiO2 and Ta2O5 materials. The emitter was designed for light emission at a wavelength of 403 nm. We analyze the influence of the size of the dielectric bottom mirrors on the operation of the laser, including its power-current-voltage (LIV) characteristics. We also study the effect of changing the electrical aperture radius (active area dimensions). We demonstrate that the appropriate selection of these two parameters enables the temperature inside the laser to be reduced, lowering the laser threshold current and increasing its optical power output significantly.

An Investigation into Sheet-Inconel 718 Forming with Flexible and Metal Tools-Simulation and Experiment.

The article presents the results of numerical simulations and experimental tests of plastic forming sheets made from the difficult-to-deform nickel alloy Inconel 718 with a thickness of 1 mm, using punches made from elastomeric materials with hardness 50-90 Shore A and steel dies. Elastomeric stamps were created in the form of five layers with a diameter of 160 mm. The influence of the hardness of the elastomeric punches on the geometry of the elements obtained was determined. The dies were made from 90MnCrV8 steel with a hardness of over 60 HRC. Their task was to obtain the expected shape of the element while generating various stress states in specific areas of the semi-finished product. The research was carried out using an original device whose operating principle was based on the Guerin method. The shape and dimensions of the elements made from Inconel 718 nickel alloy were determined by optical 3D scanning. The geometry of the drawpiece showed a significant impact of the hardness of the layered elastomer matrices on the degree of shape reproduction. The results obtained from numerical modeling were confirmed by the results of experimental tests. It has been shown that the hardness of the elastomeric material used for punches for plastic forming Inconel 718 nickel alloy sheets should be adapted to the shape of the drawpiece. It was also found that one of the important aspects of plastic forming sheets using the Guerin method is the tendency to obtain a diversified shape of the final elements.

Energy Absorption and Failure Modes of Different Composite Open-Section Crush Elements under Axial Crushing Loading.

In order to study the energy absorption characteristics of the open-section thin-walled composite structures with different cross-sections, axial compression tests were carried out at loading speeds of 0.01 m/s, 0.1 m/s, and 1 m/s. Finite element models were built to predict the crushing response and energy absorption behaviors of these open-section structures. The effects of the cross-section's shape, cross-section aspect ratio, trigger mechanism, and loading speed on the energy absorption characteristics of the composite structures were analyzed. The results show that the average crushing loads of the hat-shaped and Ω-shaped open-section structures are 14.1% and 14.6% higher than those of C-shaped open-section structures, and the specific energy absorption (SEA) values are 14.3% and 14.8% higher than that of C-shaped open-section structures, respectively. For the C-shaped open-section structures, a 45° chamfer trigger is more effective in reducing the initial peak load, while a 15° steeple trigger is more appropriate for the hat-shaped open-section structures. The average crushing loads and SEA of C-shaped, hat-shaped, and Ω-shaped open-section structures are reduced when the loading speed is increased from 0.01 m/s to 1 m/s. The increase in loading speed leads to the splashing of debris and thus reduces the loading area and material utilization of open-section structures, leading to a decrease in energy absorption efficiency.

Study on the Nodal Composite Bearing Performance of Nontruncated PHC Pipe Pile and Bearing Platform.

In this paper, low circumferential reciprocating load foot-scale tests were performed on two nontruncated PHC B 600 130 tubular piles with bearing nodes to characterize the damage process and morphology of the specimens and to investigate the load-carrying performance of the members. The test results reveal that under the action of tensile-bending-shear loading, the bearing concrete in the node area buckles and is damaged, the anchored reinforcement in the node area yields, the constraint is weakened, an articulation point is formed, and the node rotational capacity increases. When the embedment depth increases from 200 mm to 300 mm, the ultimate bearing capacities of the positive and negative nodes increase by 31.04% and 36.16%, respectively. A numerical simulation is used to verify the test results. Considering the four types of piles without truncated nodes, the numerical simulation is used to analyze the node-bearing capacity at different embedment depths. Finally, a preferred node type is proposed as follows: a terminal plate welded anchor bar and pipe pile core-filled longitudinal reinforcement anchored into the bearing node, with a preferred embedment depth of 250 mm.

Numerical simulation on transient electromagnetic response of separation layer water in coal seam roof.

Mining stress induces deformation and fracture of the overlaying rock, which will result in water filling the separation layer if the aquifer finds access to abscission space along the fracture channels. Accurate detection is crucial to prevent water hazards induced by water-bearing fractures. The 3-D time-domain finite-difference method with Yee's grid was adopted to calculate full-space transient electromagnetic response; meanwhile, a typical geologic and geophysical model with a water-bearing block in an separation layer was built according to regional tectonics and stratigraphic developments. By using numerical simulation, the induced voltage and apparent resistivity for both vertical and horizontal components were acquired, and then an approximate inversion was carried out based on the "smoke ring" theory. The results indicate that the diffusion velocity of induced voltage is significantly affected by the water-bearing body in the fracture, and the horizontal velocity of induced voltage is lower than the vertical one. The induced voltage curves indicate that the horizontal response to an anomaly body is stronger than the vertical one, leading to a high apparent resistivity resolution of conductivity contrast and separation layer boundary in the horizontal direction. The results of 3-D simulation making use of a measured data model also demonstrate that the horizontal component of apparent resistivity can reflect the electrical structure in a better way; however, its ability to recognize the concealed and fine conductor is rather weak. Accordingly, the observation method or numerical interpolation method needs to be further improved for data processing and interpretation.

Experimental study of the effects of the void located at the pile tip on the load capacity of rock-socketed piles.

To address the design challenge of the rock-socketed piles posed by the void located below the pile tip, the physical laboratory model tests were designed and performed to simulate rock socketed piles using similar materials. The study investigates the behavior of the single pile under axial loading with the void located at varying distances from the pile tip. Through multi-level load tests, the variations of unit pile side friction, pile tip resistance, pile axial force and pile settlement are obtained for different positions of the void from the pile tip, as well as after grouting. Its comparison to the rock-socketed pile without void is performed as a reference to quantify the reduction in its bearing capacity. The results are presented in the form of graphs for different void positions and its grouting shows the influence on pile bearing capacity and emphasizes the importance of its detailed cautious investigation and introduction in the analysis. The 2D finite element modeling of the model pile-the void based on ABAQUS is performed to further investigate the influence of the void below pile tip on the bearing capacity of model pile, applying the Mohr Coulomb model as the constitutive model of rock mass behavior. The critical distance of the void below the pile tip is determined.

Effect of airflow rate on droplet deposition of an impinging-jet inhaler in the human respiratory tract.

This paper presents a numerical investigation to understand the transport and deposition of sprays emitted by an impinging-jet inhaler in the human respiratory tract under different inhalation flow rates. An injection model is used for the numerical simulations considering the spreading angles of the spray in the two directions, which are measured from experiments. The model parameter is adjusted to match the mean droplet size measured in the previous experiment. A time-varying sinusoidal inhalation flow rate is utilized as airflow conditions, which is closer to the actual situation when using an inhaler. The results demonstrate that the inhalation airflow rate significantly affects the spray's transport behavior and deposition results in the respiratory tract. Both excessively high and low inhalation flow rates lead to an increase in deposition in the mouth-throat. A moderate inhalation flow rate reduces throat deposition while maximizing lung deposition. Higher inhalation flow rates enable faster delivery of the droplets to the lungs, whereas lower inhalation flow rates achieve a more uniform deposition over time in the lungs. The amount of deposition in different parts of the lung lobes follows a fixed order. This study provides valuable insights for optimizing the inhalation flow rate conditions of the impinging-jet inhaler for clinical applications.

Effect of bridge height on airflow and aeolian sand flux near surface along the Qinghai-Tibet Railway, China.

In this work, we studied the near-surface flow field structure of railway bridges with different heights through field investigation and wind tunnel simulation experiments. Meanwhile, we simulated the distribution of sand accumulation around a bridge via CFD software based on the sand accumulation around the Basuoqu bridge in the Cuona Lake section of the Qinghai-Tibet Railway. Results show that the sand around this railway bridge is mainly from the lake sediment on the west side of the railway and the weathered detritus on the east side. The height of the railway bridge in the sandy area affects the distribution of the near-surface flow field and the variation in speed on both sides of the bridge. The wind speed trough on both sides of the 6 m high bridge is higher, and the horizontal distance between the wind speed trough and the bridge section is 1.5 times that of the 3 m high bridge. Wind speed attenuates in a certain range on the windward and leeward sides of the bridge, forming an aeolian area; under the beam body, it is affected by the narrow tube effect, forming a wind erosion area. The height of the bridge determines its sand transport capacity. Under certain wind conditions, the overhead area at the bottom of the 3 m high bridge and its two sides do not have the sand transport capacity, so sand accumulates easily. Nevertheless, the sand accumulation phenomenon gradually disappears with the increase in bridge clearance height. The objectives of this study are to reveal the formation mechanism of sand damage for railway bridges, provide theoretical support for the scientific design of railway bridges in sandy areas, and formulate reasonable railway sand prevention measures to ensure the safety of railway running, which have certain theoretical significance and practical value.

Study on the dynamic response and roadways stability during mining under the disturbance of hard roof break.

Under the condition that the working face was directly covered with hard roof, the abrupt breaking of hard roof release significant amount of energy, thus prone to triggering dynamic disasters such as roadway instability or rockburst. This paper based on the engineering background of the Xieqiao Coal Mine's 11,618 working face, a numerical simulation method was put forward to study the dynamic response of roadway under the disturbance of hard roof breaking and proposed an evaluation index IC for roadway stability. Research indicates that the elastic energy released during the periodic weighting of the hard roof is higher than that released during the first weighting. Under the dynamic disturbance caused by hard roof breaking, the peak stresses of the roadway was slight decreased, accompanied by a significant increase in the range of stress concentration and plastic zone expansion. Roadway deformation patterns are significantly influenced by hard roof breaking, with noticeable increases in deformation on the roof and right side. During the period of hard roof breaking, the possibility of instability of the roadway increase significantly due to the disturbance caused by the dynamic load. The research results reveal the instability mechanism of roadway under the condition of hard roof, and provide a more reliable basis for evaluating the stability of roadway.

Numerical simulation application in occupational health studies: a review.

Most occupational hazardous agents in workplaces should be evaluated and controlled. Different methods exist for identifying, evaluating and controlling these agents, such as numerical simulation tools. Numerical simulations can help experts to improve occupational health. Due to the importance and abilities of numerical simulations, this study divided occupational hazardous agents into 10 subgroups. These subgroups included air pollution, ventilation, respiratory airways, noise and vibration, lighting, radiation, ergonomics, fire and explosion, risk assessment and personal protective equipment. Recent research studies in each subgroup were then reviewed, and the codes and software used in simulations were determined. The results show that Fluent software and k-ϵ turbulence models are the most used in occupational health studies simulations. Today, different codes and software have been developed for simulation, and we suggest their use in occupational health studies.

Dielectrophoretic separation and purification: From colloid and biological particles to droplets.

It is indispensable to realize the high level of purification and separation, so that objective particles, such as malignant cells, harmful bacteria, and special proteins or biological molecules, could satisfy the high precise measurement in the pharmaceutical analysis, clinical diagnosis, targeted therapy, and food defense. In addition, this could reveal the intrinsic nature and evolution mechanisms of individual biological variations. Consequently, many techniques related to optical tweezers, microfluidics, acoustophoresis, and electrokinetics can be broadly used to achieve micro- and nano-scale particle separations. Dielectrophoresis (DEP) has been used for various manipulation, concentration, transport, and separation processes of biological particles owing to its early development, mature theory, low cost, and high throughput. Although numerous reviews have discussed the biological applications of DEP techniques, comprehensive descriptions of micro- and nano-scale particle separations feature less frequently in the literature. Therefore, this review summarizes the current state of particle separation attention to relevant technological developments and innovation, including theoretical simulation, microchannel structure, electrode material, pattern and its layout. Moreover, a brief overview of separation applications using DEP in combination with other technologies is also provided. Finally, conclusions, future guidelines, and suggestions for potential promotion are highlighted.

The influence Cl- on stress corrosion of 7xxx series aluminium alloys studied by experimental and simulation technology.

The stress corrosion behavior of 7xxx series aluminium alloys in different concentrations NaCl solution was studied, and numerical simulation was conducted in COMSOL Multiphysics based on experimental results. Different stresses were applied on the experiment pieces, the pitting crater deepened with the change of stress level. The corrosion rate increased with the raising stress. There is no positive correlation between stress corrosion degree and chloride ion concentration. The most severe corrosion occurs in 5.0 wt% NaCl solution instead of 6.0 wt% NaCl solution due to the increase of water film conductivity and decrease of solubility of oxygen under high Cl- environment. The finite element model was used to analyze the stress distribution on aluminium alloy surface, to describe the dynamic equation of anodic dissolution of metal due to elastic and plastic deformation. Corrosion occurs mainly in stress concentrated areas. When the stress loading exceeds a certain threshold, plastic strain occurs on the surface of both the specimen and the structural part, the corrosion current density increases instantaneously, and the corrosion behavior in the stress concentration area gradually intensifies. The survey can provide practical theoretical guidance for predicting stress corrosion and extending the service life of equipment in (harsh) marine environments.

Chaos control in cardiac dynamics: terminating chaotic states with local minima pacing.

Current treatments of cardiac arrhythmias like ventricular fibrillation involve the application of a high-energy electric shock, that induces significant electrical currents in the myocardium and therefore involves severe side effects like possible tissue damage and post-traumatic stress. Using numerical simulations on four different models of 2D excitable media, this study demonstrates that low energy pulses applied shortly after local minima in the mean value of the transmembrane potential provide high success rates. We evaluate the performance of this approach for ten initial conditions of each model, ten spatially different stimuli, and different shock amplitudes. The investigated models of 2D excitable media cover a broad range of dominant frequencies and number of phase singularities, which demonstrates, that our findings are not limited to a specific kind of model or parameterization of it. Thus, we propose a method that incorporates the dynamics of the underlying system, even during pacing, and solely relies on a scalar observable, which is easily measurable in numerical simulations.

Numerical simulation of blasting behavior of rock mass with cavity under high in-situ stress.

With the shift of coal seam mining to the deep, the in-situ stress of coal and rock mass increases gradually. High ground stress can limit the generation of rock cracks caused by blasting, and blasting usually shows different crushing states than low stress conditions. In order to study the blasting expansion rule of rock mass with cavity under high ground stress and the rock mass fracture state under different side stress coefficients. In this paper, the effective range of blasting and the stress distribution under blasting load are analyzed theoretically. The RHT (Riedel-Hiermaier-Thoma) model is used to numerically simulate the blasting process of rock mass with cavity under different ground stress, and the influence of ground stress and lateral pressure coefficient on the crack growth of rock mass is studied. The results show that when there is no ground stress, the damage cracks in rock mass are more concentrated in the horizontal direction and the fracture development tends to the direction where the holes are located, which confirms the guiding effect and stress concentration effect of the holes in rock mass, which helps to promote the crack penetration between the hole and the hole. The length difference of horizontal and vertical damage cracks in rock mass increases with the increase of horizontal and vertical stress difference. Under the same lateral stress coefficient, the larger the horizontal and vertical stress difference is, the stronger the inhibition effect on crack formation is. For blasting of rock mass with high ground stress, the crack formation length between gun holes decreases with the increase of stress level, and the crack extends preferentially in the direction of higher stress. Therefore, the placement of gun holes along the direction of greater stress and the shortening of hole spacing are conducive to the penetration of cracks between gun holes and empty holes. The research can provide reference for rock breaking behavior of deep rock mass blasting.