Blasthole Diameter Research Articles

Minimizing community impact: A new approach to blasthole diameter selection.

This study introduces a comprehensive methodology for selecting blasthole diameters in open-pit mining, aiming to reduce the environmental impact while addressing the limitations of traditional empirical methods that often yield suboptimal productivity, cost efficiency. By integrating critical parameters such as bench height, rock and explosive properties, desired fragmentation size, production scale, and operational specifics, the methodology seeks to minimize negative effects on nearby communities while optimizing blasting practices. The methodology consists of four key steps: calculating potential diameters based on bench height, verifying influential factors affecting diameter selection, assessing environmental impacts of blasting activities, such as blasting-induced vibration and flyrock, and ultimately choosing the optimal diameter. This systematic approach ensures that all relevant aspects, including explosive critical diameter and velocity of detonation, are considered. The integration of environmental and geotechnical limitations and parameters enhances its practical applicability. Validation was performed at an open-pit iron mine situated near a populated area, demonstrating the methodology's effectiveness in achieving reduction in environmental impacts while adhering to fragmentation requirements. The results indicate its broad applicability across various mining operations, effectively balancing community safety with technical requirements. In conclusion, this study significantly advances the field of environmental and mining engineering by providing a scientifically grounded approach to blasthole diameter selection. The findings highlight the importance of a holistic perspective that encompasses environmental, technical and economic factors in blasting operations. By adopting this methodology, mining companies can mitigate their environmental footprint and fostering better relationships with surrounding communities while enhancing operational efficiency.

Correlation of Rock and Blast Properties with Elevated Quarry Floor and their Effects on Mining Costs

This study investigates the relationships between rock properties, blasting parameters, and their impact on quarry floor elevation and mining costs at Mount Olives quarry. Rock properties (uniaxial compressive strength, tensile strength, density) and blasting parameters (blast hole diameter, explosive type, stemming length) were analyzed. Statistical models correlated rock, blast, and quarry floor properties. Results showed significant correlations between rock properties and blasting parameters, affecting quarry floor elevation and mining costs. Compressive strength and tensile strength influenced blast energy, while rock density impacted quarry floor stability. Mining costs were predicted using statistical models incorporating rock and blast properties. This research demonstrates the importance of understanding rock and blast interactions in optimizing quarry operations and reducing mining costs. The findings provide valuable insights for quarry managers, blasting engineers, and geotechnical professionals.

Modeling and simulation on spontaneous detonation of ammonium nitrate explosive induced by sulfide ores.

In this work, the characteristics of the exothermic reaction between ammonium nitrate and sulfide ores were explored using COMSOL Multiphysics. This reaction can cause an increase in temperature within the blast holes of sulfide mines and can potentially induce premature explosions of the explosives. Initially, simulations were conducted to observe temperature variations in blast holes before and after the loading of explosives. Then, the impact of blast hole diameter and initial temperature on the thermal environment was assessed. Subsequent analysis focused on the fluid field's dynamics, examining flow rate changes and the concentration of signature gases produced by the reaction. Additionally, the influence of blast hole diameter on these parameters was evaluated. The results show that the blast hole temperature is positively related to its diameter and initial temperature. When the diameter of the blast hole is 120mm and 165mm, a significant change in flow rate is observed, with a trend of being rapidly increased and then rapidly decreased. The production of NH3 is always found to be greater than that of the other two gases. As for NO and SO2, their production is characterized by an approximate ratio of 1:2. The numerical simulation results can provide important theoretical guidance for the spontaneous detonation of blast hole in sulfide mines.

Experimental study on the influences of charging structure with various filling mediums on rock blasting performances

Decoupled charge blasting is widely used in tunnel contour excavation to mitigate overbreak/underbreak and the extent of excavation damaged zone, which plays a pivotal role in enhancing the safety and efficiency of tunnel construction. This study experimentally investigates the influences of filling medium (air, water, sand and clay) on blasting performances. Five single hole blast (SHB) tests with a blasthole length of 1.0 m and blasthole diameter of 45 mm are first conducted in an underground tunnel. The ground vibration signals are captured using three-component seismic vibrometers installed at different distances away from the blasthole. The blast-induced crater is automatically measured using a 3D laser scanner and the post-blast rock fragmentation is analyzed using the open-source program ImageJ. Subsequently, the peak pressure, particle velocity and displacement on the borehole wall with respect to various filling mediums are theoretically deduced and analyzed. The experimental results indicated that the fully coupled blasting produces the largest near-field peak particle velocity (PPV), finest rock fragmentation and largest crater, but also the highest PPV attenuation rate. Among these decoupled charge blasts, water-decoupled blasting results in the finest fragmentation and maximum crater, whereas the corresponding PPV is at a much smaller level than coupled blasting. Sand and clay-decoupled blasts yield smaller PPV and crater but coarser fragmentation than water-decoupled blasting. Air-decoupled charge structure causes the minimum PPV and crater size, as well as the coarsest fragmentation. The theoretical analysis shows that the fully coupled blasting yields the largest borehole wall pressure (BWP), particle velocity and displacement on borehole wall than those induced by decoupled blasts, as well as the maximum attenuation rate of BWP and velocity. Additionally, water-decoupled blasting exhibits higher energy transfer efficiency so that a finer rock fragmentation and a larger crater are obtained than air, clay and sand decoupled blasts, but more attention should be paid to the blast vibration.

The Effect of the Blasthole Diameter on the Detonation Velocity of Bulk Emulsion Explosive in the Conditions of Selected Mining Panel of the Rudna Mine

The blasting technique is currently the basic excavation method in Polish underground copper mines. Applied explosives are usually described by parameters determined on the basis of specific standa ...

Sensitivity analysis on blast design parameters to improve bench blasting outcomes using the Taguchi method

In surface mines, bench blasting is a typical way of excavating hard rock mass. Although a significant development has taken place in explosive technology but still only a part of the energy is used to excavate and a large proportion of energy is wasted away and creates a number of nuisances. Backbreak, massive rock fragmentation, and high-intensity ground vibration are all symptoms of improper blasting. As a result, production costs increase significantly while productivity decreases. The blasting outcomes are affected by a variety of factors, which may be classified into three categories: rock properties, explosive properties, and blast geometry. Consequently, it is necessary to examine the effect of these parameters on bench blasting. So, in this study, a sensitivity analysis has been performed on various blast design parameters using the Taguchi method to study the influence of blast design parameters on blast vibration, backbreak, and rock fragmentation. A total of 32 experiments have been designed and numerical modeling was also carried out, using LS DYNA software to simulate the blast results. It was found that the blast hole diameter is the most important factor influencing the blasting outcomes. However, the number of rows in a blast affects backbreak almost slightly more than the hole diameter, but blast vibrations and the surrounding rock damage strongly depend on the hole diameter. Furthermore, rock blast geometry significantly affected rock blast vibration and damage compared to explosive properties. However, both blast geometry parameters and explosive properties play a significant role in backbreaking.

Research on Rock Damage Evolution Based on Fractal Theory-Improved Dynamic Tensile-Compression Damage Model

According to the characteristics that the dynamic tension of rock material is elastic brittle and the dynamic compression is elastic plastic, based on previous studies, the influence of initial damage is considered in the established compression damage model, and the calculation formula of the damage threshold used to evaluate whether the surrounding rock is affected by blasting is given. According to the classic rock impact dynamic damage model and statistical damage mechanics theory, a rock compressive and tensile statistical damage constitutive model and impact damage model under blasting load is proposed. Based on the proposed damage model and the classic dynamic tensile damage model, the numerical simulation of blasting damage was carried out, and the numerical calculation results were compared with the field measurement results. Based on the established damage model, to further clarify the damage evolution characteristics of rock under blasting load, fractal dimension theory was introduced to analyze the rock damage under blasting loads with different blasting hole network parameters. The results show that compared with the axial direction of the blast hole, the direction of blast hole diameter is the main direction of blasting fracture extension. Tensile fracture mainly occurs along the hole diameter direction, and compression fracture mainly occurs below the hole bottom. Compared with the numerical calculation results based on the classical dynamic tensile damage model, the blasting fracture range obtained according to the damage model, especially the fracture depth below the bottom of the hole, was not much different from the measured value and was closest to the measured value. The crack density of 1 us, 90 aperture, and 130 aperture was larger than that of the other working conditions. Among them, the crack density of 130 aperture was the largest, followed by 90 aperture. At 2~3 us after initiation, cracks between two blast holes, radial cracks and circumferential cracks around two blast holes, and obvious cracks were formed around blastholes; at 4~5 us after initiation, the shock wave front decreased rapidly and propagated outward in the form of the compression wave. The crack propagation velocity was much smaller than that at 1~3 us after initiation. In summary, the proposed damage model is reasonable and has certain engineering practicability.

Research on Optimal Design of Pressure Relief Blasting Parameters of Middle Rock Pillar in Near Vertical Coal Seam

In order to prevent the occurrence of rockburst accident caused by the stress concentration of the middle rock pillar in the near-vertical coal seam and affect the mining of the lower coal seam in the known goaf, taking Wudong coal mine in Xinjiang as an example, based on the special geological and mining conditions of the mine, through the simulation experiment and numerical analysis of similar materials, the variation law of the stress distribution of the middle rock pillar with the increase in mining depth is analyzed. A presplitting blasting pressure relief technology of drilling a construction chamber in the middle of the rock column is proposed to form a buffer layer in the rock wall and effectively prevent the continuous downward movement of stress. In order to achieve the optimal blasting effect, the finite element numerical simulation software GTS NX is used to carry out the chamber rock mass hole blasting simulation experiment, the three influencing factors of blasting effect, such as charge quantity, blast hole diameter, and blast hole row spacing, are comprehensively considered, and the optimal pressure relief blasting parameters with the radius of borehole blasting crack circle and the width of plastic zone as the index are determined. The experimental results show that under the condition of determining the physical and mechanical parameters of coal and rock, the blast hole diameter has become the main control factor affecting the blasting pressure relief effect, followed by the charge amount. Through 9 groups of orthogonal tests, the optimal combination of the three indexes is 6 kg charge, 150 mm hole diameter and 10 m hole row spacing. The practical engineering application results of the combination are tested by downhole transient electromagnetic detection (TEM), and it is found that the pressure relief effect is obvious. The preliminary conclusions of the study have guiding significance for the pressure relief and erosion prevention of the middle rock pillar in Wudong mine and provide experimental methods and theoretical basis for the determination of blasting pressure relief parameters in other mines.

Comparison of dominant frequency attenuation of blasting vibration for different charge structures

Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration control. It is necessary to develop a concise and practical prediction equation describing dominant frequency attenuation. In this paper, a prediction equation of dominant frequency that accounts for primary parameters influencing the dominant frequency was proposed based on theoretical and dimensional analyses. Three blasting experiments were carried out in the Chiwan parking lot for collecting blasting vibration data used to conduct regression analysis of the proposed prediction equation. The fitting equations were further adopted to compare the reliability of three different types of dominant frequencies in the proposed equation and to explore the effects of different charge structures on the dominant frequency attenuation. The apparent frequency proved to be more reliable to express the attenuation law of the dominant frequency. The reliability and superiority of the proposed equation employing the apparent frequency were verified by comparison with the other five prediction equations. The smaller blasthole diameter or decoupling ratio leads to the higher initial value and corresponding faster attenuation of the dominant frequency. The blasthole diameter has a greater influence on the dominant frequency attenuation than the decoupling ratio does. Among the charge structures applied in the experiments, the charge structure with decoupling ratio of 1.5 and blasthole diameter of 48 mm results in the greatest initial value and corresponding fastest attenuation of the dominant frequency. • Prediction equation of dominant frequency attenuation in surface blasting. • Comparing attenuation laws using three different types of dominant frequencies. • Effects of blasthole diameter and decoupling ratio on attenuation characteristics.

Study on parameter optimization of deep hole cumulative blasting in low permeability coal seams

Coal seam gas extraction is an important means of exploiting and utilizing gas resources, as well as a means of preventing coal mine disasters. To improve gas extraction efficiency in high gas and low permeability coal seams while ensuring blasting security, deep hole cumulative blasting parameters were optimized. ANSYS/LS-DYNA software is used to establish a 3-dimensional cumulative blasting model. By comparing and analyzing the blasting stress nephograms, stress time-history curves, and crack expansion curves, the optimal blasthole diameter, charge position, and charge length are obtained. Based on the numerical simulation results, a field test was carried out in the No. 10 coal seam of the Pingdingshan coal mine. The test results show that after cumulative blasting, the gas concentration was increased by an average of 2.25 times, the gas purity was increased by an average of 3.78 times, the permeability coefficient of the coal seam was increased by 21 times, and the effective radius of blasting was up to 7 m. The positive effects of deep hole cumulative blasting parameter optimization on the pressure relief and permeability enhancement of a high gas and low permeability coal seam were determined, which can provide a reference for other similar working faces to implement this technology.

Explosion wave and crack field of an eccentric decoupled charge.

To investigate the characteristics of the explosion damage from an eccentric decoupled charge, the rock-breaking mechanism of an eccentric decoupled charge is revealed from the perspectives of the explosion wave field and crack field through theoretical and experimental analyses. The ratio of the maximum to minimum pressure on an eccentric decoupled hole wall increases exponentially with an increase in the decoupling coefficient, but it does not change with a change in the explosive density or explosive detonation velocity. The explosive energy on the eccentric charge side has a certain accumulation effect, the velocity of the reflected shock wave at the blasthole wall is greater than that of the incident shock wave, and the incident velocity of the explosion wave on the eccentric side is greater than that on the non-eccentric side. The expansion range of the explosion gas is significantly better than that on the non-eccentric side, indicating that the eccentric decoupled charge can strengthen the action of the explosion gas product on the eccentric side. In addition, the overpressure of the explosion wave on the eccentric side is greater than that on the non-eccentric side. The fractal dimension and damage degree of the explosion crack on the eccentric side are larger than those on the non-eccentric side. The explosion cracks can be divided into intensive, transition, and sparse areas, and the fractal dimension and damage degree decrease successively in the three areas. The explosion cracks formed on the non-eccentric side outside the range of three times the blasthole diameter concentrate in the sparse area, and the destructive effect of the explosion on the non-eccentric side medium is effectively reduced.

Numerical study on crack propagation of rock mass using the time sequence controlled and notched blasting method

In order to solve the directional fracture controlled problem of blasting construction in key parts or specific areas of some projects, two refined directional blasting methods, namely, time sequence controlled (TSC) blasting and notched blasting, are innovatively combined, and numerical comparison research of three kinds of compound blasting methods has been carried out. The results indicate that, for TSC blasting, the optimum delayed denotation time is a certain period of time when the explosive stress wave of the earlier detonated blasthole (EDB) propagates to the wall of the later detonated blasthole (LDB) that away from the EDB. In the TSC-notched blasting with four blastholes as a group, when the LDB and EDB is notched separately, the corresponding directional fracture length is 33.3 d and 45.2 d (d is the blasthole diameter), and the directional fracture length is 52.4 d as the blastholes are all notched. If it is needed to consider both the crack propagation effect and the construction costs, we suggest that the TSC-notched blasting with the notched EDB and the round LDB should be carried out, by which the quality of the profile could be ensured with a low construction cost.

An empirical approach for predicting burden velocities in rock blasting

An analytical relation between burden velocity and ratio of burden to blasthole diameter is developed in this paper. This relation is found to be consistent with the measured burden velocities of all 37 full-scale blasts found from published articles. These blasts include single-hole blasts, multi-hole blasts, and simultaneously-initiated blasts with various borehole diameters such as 64 mm, 76 mm, 92 mm, 115 mm, 142 mm and 310 mm. All boreholes were fully charged. The agreement between measured and calculated burden velocities demonstrates that this relation can be used to predict the burden velocity of a wide range of full-scale blast with fully-coupled explosive charge and help to determine a correct delay time between adjacent holes or rows in various full-scale blasts involved in tunnelling (or drifting), surface and underground mining production blasts and underground opening slot blasts. In addition, this theoretical relation is found to agree with the measured burden velocities of 9 laboratory small-scale blasts to a certain extent. To predict the burden velocity of a small-scale blast, a further study or modification to the relation is necessary by using more small-scale blasts in the future.

Contour blasting parameters by using a tunnel blast design mode

The quality of contour blasting depends on many initial blasting parameters. The parameters including blasthole diameter, rock Protodyakonov coefficient, tunnel area and distance between cracks on the tunnel face are more important. In this study, an algorithm linking between Delphi programming language and AutoCAD was created to develop a tunnel blasting model. Using this model, tunnel contour blasting passport in AutoCAD can be obtained automatically. The effects of rock Protodyakonov coefficient and cracks’ distance on blastholes number and specific charge with the variation of blasthole diameter and the semi-circular tunnel face area were investigated to yield a set of equations with the highest correlations. The results show that specific charge increases as rock Protodyakonov coefficient, cracks’ distance and drillhole diameter increase, but decreases when tunnel face area increases. In addition, the number of drillholes increases linearly as tunnel face area increases but decreases when drillhole diameter increases.

Development of a new empirical fragmentation model using rock mass properties, blasthole parameters, and powder factor

Rock fragmentation as one of the most important blasting results plays an indispensable role in subsequent stages such as secondary breakage, loading, hauling, crushing and grinding, and relevant energy consumption. Since several rock mass properties, blasthole parameters, and powder factor can affect the fragmentation results, development of an accurate model to predict fragment size has long been a complicated subject. In this study, rock mass properties, blasthole parameters, powder factor (q), and fragment size distribution of blasted rock using image analysis technique were determined for several blasting operations in different zones of Sungun open pit copper mine, Rashakan limestone mine, Soufian limestone mine, and Golgohar open pit iron mine. The median fragment size (X50) varied from 10.4 to 32.1 cm, and the predicted X50 by the modified Kuz–Ram models was significantly different from the X50 of the results. Because only a coefficient has been changed from one model to another and the impact of the combination of the parameters on X50 has not yet been well investigated, the impact of individual essential parameters such as blasthole diameter (ϕh), charge per blasthole (Q), rock mass properties, and q on the X50, X80, and uniformity index (n) was originally analyzed to clarify how their combination affects the fragment size of blasted rocks. ϕh and Q had a similar or a parallel effect on the fragmentation results. Two types of relations between X50 with the new combination of Q, q, SANFO, and blastability index (BI) and X50 with the combination of ϕh, q, SANFO, and BI with acceptable correlations were obtained and the correlations also increased when the parameter of joint plane spacing (JPS) was adjusted in the BI system. At the end, a new empirical model was achieved to predict X50 as a function of combination of Q, q, SANFO and adjusted BI with higher correlation (R2 = 0.865), less root mean square error (RMSE = 3.3 cm), and less coefficient of variation (CV = 19.9%) with actual field results.

Assessment of the effect of blasthole design parameters on total cost in quarries

Crushed stone is the most important raw material for concrete and asphalt production. As a high-volume low-unit-value industry, the crushed stone production sector is highly competitive which implies the necessity to optimise the costs of all of its production operations, i.e. drilling and blasting, secondary breaking, loading, hauling and crushing. In this context, this paper investigates the effect of bench blasting design parameters on the unit-costs and total production cost of aggregate production. For this purpose, 40 blasts were conducted and investigated. The studied parameters included different blasthole length (12 m, 15 m, 18 m, 21.5 m and 25 m) and diameter (89 mm and 102 mm), in addition to different spacing, burden and stemming length. As a result, it was found that an increase in blasthole length led to an increase in the unit cost of drilling operation. In addition, it was found that a blasthole length of 15 m ensured optimum fragmentation, diminishing the costs of subsequent operations. Incrementing the blasthole diameter from 89 to 102 mm reduced the total unit cost by 0.091 $/m3. Incrementing the burden and spacing by 0.25 m also decreased the total unit cost by 0.097 $/m3. However, accreting the stemming length by 0.5 m induced a slight decrease in the total unit cost by 0.026 $/m3.

Initiation of residual stress zone during blasting in jointed granite rock mass in operation of Priargunsky Industrial Mining and Chemical Union

Russian and foreign technical literature says that blasting in jointed rock mass induces zones with altered physical properties and geomechanical behavior beyond the perimeter holes. These zones are identified as the crushed zone, radially fractured zone, spalling zone and shattered zone. The shattered zone lacks scientific attention although this zone can reach the width of (30–170)db (db—blasthole diameter) in open pit mines and (25–75)db in underground mines. The earlier implemented research answers the question on quantitative change in the stresses and strains of a jointed rock mass during blasting. The initiation mechanism of the shattered zone remains unclear. This study aims to find the initiation mechanism of the shattered zone in jointed rock mass and to determine its stress state after blasting. Three series of full-scale experimental studies have been performed in jointed granite rock mass using acoustic emission methods, ultrasonic techniques and deformation measurements. It is found that in the shattered zone, blocks in the jointed rock mass displace radially from the blast holes with deformation of the joint surfaces and with elastic strains preserved after blasting. For this reason, this zone is qualified as the zone of blast-induced residual stresses. The article gives the formula for the residual radial compressive stresses under short-delay multi-row blasting. The numerical calculation using this formula and the actual mine data prove the formula validity. The method of destressing blasting is proposed to unload rockburst-hazardous rock mass from stresses in the areas of the confining pressure phenomena such as spalling and sloughing. This method has been trialed in Priargunsky’s mines in granite rock mass (1400 m long area was unloaded from stresses in mines). The authors highly appreciate participation of I. I. Shishkin, B. M. Belyaev, V. M. Pankov and V. A. Pazdnikova in the experimental research.

Explosion wave and explosion fracture characteristics of cylindrical charges

The distribution characteristics of the explosion wave field of a cylindrical charge were investigated in this paper via a high-speed schlieren experiment. Based on the fractal theory, the paper studies the crack propagation characteristics of the media under the action of the cylindrical charge explosion impact at different initiation points. The results show that the velocity of detonation appeared attenuation region when the detonation wave changes to the shock wave, and a certain angle of detonation wave ranging from 580to 62°. Based on the schlieren experiment and the theoretical model, the included angle between the explosion wave in the vicinity of the detonation point and the blasthole wall surface is about 90°, during a stable explosion, the ultimate included angle between the explosion wave and the blasthole wall surface is about 60°. Based on the analysis of the propagation characteristics of the explosion cracks of the cylindrical charge, the angle of incident makes the initiation and propagation of the cracks around the blasthole deflect and the angle of deflection coincides with the theoretical calculation value. The pulverization zone formed in the vicinity of the detonation point is larger than in other zones, but the crack zone is smaller than in other zones. Moreover, the cracking range produced by the cylindrical charge is roughly the range of its five-fold blasthole diameter. There were significant fractal characteristics, within the range of one-to two-fold blasthole diameter, the medium is completely pulverized and forms a zone of dense cracks; within the range of three-to four-fold blasthole diameter, the medium is severely damaged and a crack transition zone forms; five-fold blasthole diameter, there are a few explosion cracks in the medium and a zone of sparse cracks forms.

Blast Design for Improved Productivity using a Modified Available Energy Method

In this work, a new drilling and blasting design methodology is introduced and applied at a case study mine to improve productivity. For the case study copper mine, a blast diameter of 203 mm is proposed to be used in the ore zone to meet the new required production rate of 90mtpa from 75mtpa. Currently, the Konya and Walter’s model is used to generate drilling and blasting design at a blasthole diameter of 172 mm. The new drilling and blast design approach is advantageous in the sense that it generates a lower specific drilling value and predicts an average fragment size compared with the current method being used. In this regard, a modified available energy blast design method that incorporates the blastability index of ore zone in the calculation of the input powder factor is introduced. The results of the blast design simulations at a 203 mm blasthole diameter shows that the modified available energy model generates a drilling and blasting design with a specific drilling value that is 15.3% less than that generated by the Ash’s and Konya and Walter’s models. Further, the modified available energy model generates a blast design with a predicted average fragment size that is 3.4% smaller than that generated by the Ash’s model, and 6.7% smaller than that generated by the Konya and Walter’s model.

An Investigation to Assess the Cause of Accident due to Flyrock in an Opencast Coal Mine: A Case Study

The paper deals with the investigation carried out to find out the possible reason of the flyrock incident causing fatality of one person at Bhurkunda ‘Á’ Colliery of Central Coalfields Limited (CCL). The flying fragment travelled up to 280 m from the blasting source causing the accidental death. The blasts were conducted in overburden rock strata consisting of medium grained sandstone and shale. The blasthole diameter used in the blast was 160 mm, and the average hole depth was 6.0 m. Site mixed emulsion (SME) explosive was used in the blast, and explosive charge per hole was 50.00 kg. Non-electric initiation systems were used for in-hole explosive and surface hole-to-hole initiations. The design parameters used in the blast were thoroughly analyzed using blast simulation software to check any anomaly in the blast design viz. sequence of hole firing, success rate of burden movement, maximum charge per delay fired within 8 ms windows, etc. The different flyrock fragments prediction models were used to assess the maximum possible travel distance of the flying in the blast. A synonymous blast was also conducted in the mines to replicate the blast where flyrock accident occurred. All the blasting events were recorded and monitored using a digital video camera. The simulation results of the blast showed the success rate of burden relief more than 80% with sufficient delay intervals for the rock movement during the blast. The maximum possible travel distance of flying fragments based on different flyrock prediction models was 227 m. In the synonymous blast, only vertical throws of the flying fragments up to 70 m (approximate) height were observed. It was difficult to find out the exact cause of flyrock incident. However, based on the detailed investigation, it was concluded that the possible cause of flying fragments travelling up to a distance of 280 m could be due to the presence of a weak zone in the rock strata.