One of the most important characters of blasting,a basic step of surface mining,is rock fragmentation because it directly effects on the costs of drilling and economics of the subsequent operations of loading,hauling ...One of the most important characters of blasting,a basic step of surface mining,is rock fragmentation because it directly effects on the costs of drilling and economics of the subsequent operations of loading,hauling and crushing in mines.Adaptive neuro-fuzzy inference system(ANFIS)and radial basis function(RBF)show potentials for modeling the behavior of complex nonlinear processes such as those involved in fragmentation due to blasting of rocks.We developed ANFIS and RBF methods for modeling of sizing of rock fragmentation due to bench blasting by estimation of 80%passing size(K_(80))of Golgohar iron mine of Sirjan.Iran.Comparing the results of ANFIS and RBF models shows that although the statistical parameters RBF model is acceptable but ANFIS proposed model is superior and also simpler because ANFIS model is constructed using only two input parameters while seven input parameters used for construction of RBF model.展开更多
The mechanism and the design parameters of blasting with air-decking are studied. The theory of detonation waves is used to investigate the processes of the one-dimensional plane detonation wave within a borehole. The...The mechanism and the design parameters of blasting with air-decking are studied. The theory of detonation waves is used to investigate the processes of the one-dimensional plane detonation wave within a borehole. The interac- tion of the rarefaction wave with an interface and reflection on a rigid wall is also analyzed. The same courses of the shock wave are also investigated. This decides the distribution of the pressure of the explosion products changing with time along the borehole. Based on the above theoretical analysis, two conditions should be met for a reasonable range of values of the air-decking ratio in blasting rock. First, the rarefaction wave from the contact interface between detonation products and air reaches the bottom earlier than that of the reflected shock wave from the end of the stemming. Second, the reflected shock wave reaches the contact interface between the detonation products and air earlier than that of the reflected rarefaction wave from the bottom of the borehole. Finally, the reasonable value of the air-decking ratio must be decided theoretically in air-decking blasting. For different explosives, the reasonable range of air-decking ratio varies from 0.15 to 0.4. This result is well consistent with what was obtained by previous researchers.展开更多
In recent years, China's overall social and economic system has undergone rapid and effective development under the promotion of personnel in various scientific research aspects. Driven by the economy, many indust...In recent years, China's overall social and economic system has undergone rapid and effective development under the promotion of personnel in various scientific research aspects. Driven by the economy, many industries in China have encountered many challenges with the advantages of such a large economic environment, but not only many challenges appear, but also challenges have also brought a lot of development opportunities. Enterprises to seize these opportunities can greatly promote their own economic rapid and effective development. Driven by the development of the social and economic system, the coal mining industry continues to develop through many measures. However, at present, the open-pit coal mines in China will produce a great vibration during blasting, which has brought a lot of harmful effects to the coal mining land. If these harmful effects are not effectively controlled, then for the coal mining enterprises will not only cause great damage to the machinery and equipment, in many cases, there will even endanger the life safety and property safety of the personnel on the site.展开更多
A precondition for correctly analyzing the stability of a slope and designing its bracing structure is to study and determine the influence of excavation blasting on the properties of weak intercalation in the layered...A precondition for correctly analyzing the stability of a slope and designing its bracing structure is to study and determine the influence of excavation blasting on the properties of weak intercalation in the layered rock slope. On the basis of in-situ stratification-cracking blasting tests, the properties of weak intercalation were investigated using the LS-DYNA3D program. The displacement distribution and compactness of weak intercalation at different positions away from the charge center and their various laws are discussed. The critical displacement of stratification-cracking （0.1 mm） was obtained, and an approximate expression of compactness were deduced. Furthermore, through the simulation of a layered rock blasting under the same geological conditions, the stratification-cracking effect of deep-hole blasting on the properties of weak intercalation was compared with that of short-hole blasting, and the influencing differences, in addition to their causes, were analyzed. The results indicated that the blasting cavity of weak intercalation in short-hole blasting with a radius of 40 mm was nearly a circle, whose radius was about 28.7 cm; whereas in deep-hole blasting with a radius of 150 mm, the shape of the blasting cavity was different from that in short-hole blasting, the radius of the cavity behind the charge （89.1 cm） was further smaller than those of the other three （138.7 cm）, and there were sharp crinkles on the surface of weak intercalation. When the distance from the charge center （DCC） was less than 40 and 150 cm in short-hole and deep-hole blasting, respectively, the displacement of weak intercalation was reduced remarkably with the increase in DCC.展开更多
This paper numerically simulates the stress development and generates a three-dimensional model of the medium-length hole blasting in infinite rock mass for continuous charge and divided charge in blasting by using th...This paper numerically simulates the stress development and generates a three-dimensional model of the medium-length hole blasting in infinite rock mass for continuous charge and divided charge in blasting by using the large-scale nonlinear dynamic analysis software LS-DYNA and the elastic-plastic model ~*MAT_PLASTIC_KINEMATIC and JWO-EOS.The differences of the decreasing rate in Von Mises effective stress of blasting,element effective stress peak of free surface,bore wall stress and acceleration are investigated.It is shown that divided charge could greatly improve the blasting effect by engineering blasting practice.展开更多
The advancement of intelligent mining in open-pit operations has imposed higher demands on geological transparency,aiming to provide a robust foundation for intelligent drilling and charging.In this study,a linear arr...The advancement of intelligent mining in open-pit operations has imposed higher demands on geological transparency,aiming to provide a robust foundation for intelligent drilling and charging.In this study,a linear array of 120 nodal seismometers was deployed along the surfaces of the C8 and C9 platforms at Fenghuang Mountain to investigate cavities within the rock mass and prevent improper intelligent charging.The seismometers were 1 m apart along measurement lines,with a 2-m spacing between lines,and the monitoring time for each line was set at 2 h.This deployment was paired with spatial autocorrelation and station autocorrelation to analyze ambient noise seismic data and image the velocity and structure within the rock mass.The results demonstrate that the locations and sizes of cavities or loose structures can be accurately identified at the prepared excavation site.Compared with traditional geological exploration methods for openpit mines,the approach in this study off ers higher accuracy,greater efficiency,reduced labor intensity,and insensitivity to water conditions.Ambient noise seismic imaging for detecting adverse geological conditions in open-pit mines provides critical insights and references for intelligent mining advancements.展开更多
Accurately predicting the powder factor during blasting is essential for sustainable production planning in low-grade mines.This research presents a method for predicting powder factor based on the heterogeneity of ro...Accurately predicting the powder factor during blasting is essential for sustainable production planning in low-grade mines.This research presents a method for predicting powder factor based on the heterogeneity of rock mass rating(RMR).Considering a low-grade metal mine as an example,this study exploited geostatistical methods to obtain independent RMR for each block unit.A three-dimensional spatial distribution model for the powder factor was developed on the basis of the relationships between the RMR and the powder factor.Subsequently,models for blasting cost and mining value were built and employed to optimize the open-pit limit.The multi-variable model based on the RMR performed well in predicting the powder factor,achieving a correlation coefficient of 0.88(root mean square error of 4.3)and considerably outperforming the uniaxial compressive strength model.After model optimization,the mean size and standard deviation of the fragments in the blast pile decreased by 8.5%and 35.1%,respectively,whereas the boulder yield and its standard deviation decreased by 33.3%and 58.8%,respectively.Additionally,optimizing the open-pit limit using this method reduced the amount of rock,increased the amount of ore,and lowered blasting costs,thereby enhancing the economic efficiency of the mine.This study provides valuable insights for blasting design and mining decisions,demonstrating the advantages and potential applications of powder factor prediction based on the heterogeneity of rock mass quality.展开更多
The paper reviews the development of prediction formulas for the fragmentation from bench blasting.Much attention has been paid to the Kuz-Ram model,its development and errors,and the mean vs.median misunderstanding.T...The paper reviews the development of prediction formulas for the fragmentation from bench blasting.Much attention has been paid to the Kuz-Ram model,its development and errors,and the mean vs.median misunderstanding.The work by the US Bureau of Mines(USBM)and Chung and Katsabanis are also reviewed,as well as the two Julius Kruttschnitt Mineral Research Centre(JKMRC)models,i.e.the crush zone model(CZM)and the two-component model(TCM),which were developed to cope with the underestimation of blasting fines.The change brought by the Swebrec distribution and the associated Kuznetsov-Cunningham-Ouchterlony(KCO)model is described.Studying distribution-free fragment sizes xP for an arbitrary mass passing P led to the discovery of the fragmentation-energy fan,and with the help of dimensional analysis,to the new fragmentation prediction model xP-frag,which has much lower errors than those of the Kuz-Ram and CZM models.展开更多
Bench blasting is commonly used in open-pit mining.Some design parameters such as positions of hole packing and caving holes have great influences on the blasting effects.In this work,with a hybrid discrete-finite ele...Bench blasting is commonly used in open-pit mining.Some design parameters such as positions of hole packing and caving holes have great influences on the blasting effects.In this work,with a hybrid discrete-finite element method,numerical simulations of bench blasting are conducted,capturing the whole continuous-discontinuous processes.Considering two engineering cases,the influences of hole packing and caving holes are evaluated.The numerical results not only lead to some improved designs by relocating the packing positions and caving holes but also indicate the reliability of the adopted numerical tools.展开更多
Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in th...Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in these industries, it can also have multiple adverse environmental impacts. One such effect is flyrock, which poses risks to nearby machinery, and residential structures, and can even lead to injuries or fatalities. To optimize blasting efficiency as well as restrict side effects, prediction of the blast aftereffects is vital. Therefore, the present work focuses on using two machine learning methods to predict the velocity of flyrock in the open pit mine. To address this issue, a comprehensive dataset was gathered from the open pit mine. Then, Decision Tree and Random Forest algorithms were employed to predict flyrock velocity. The Random Forest model demonstrated superior performance compared to the Decision Tree model. Nonetheless, the performance of the Decision Tree model was deemed satisfactory, as evidenced by its coefficient of determination value of 0.83, mean squared error (MSE) of 4.2, and mean absolute percentage error (MAPE) of 5.6%. Considering these metrics, it is reasonable to conclude that tree-based algorithms can be effective in predicting flyrock velocity.展开更多
基金financially supported by the Special Fund of Islamic Azad University,Malayer Branch(No.2293)
文摘One of the most important characters of blasting,a basic step of surface mining,is rock fragmentation because it directly effects on the costs of drilling and economics of the subsequent operations of loading,hauling and crushing in mines.Adaptive neuro-fuzzy inference system(ANFIS)and radial basis function(RBF)show potentials for modeling the behavior of complex nonlinear processes such as those involved in fragmentation due to blasting of rocks.We developed ANFIS and RBF methods for modeling of sizing of rock fragmentation due to bench blasting by estimation of 80%passing size(K_(80))of Golgohar iron mine of Sirjan.Iran.Comparing the results of ANFIS and RBF models shows that although the statistical parameters RBF model is acceptable but ANFIS proposed model is superior and also simpler because ANFIS model is constructed using only two input parameters while seven input parameters used for construction of RBF model.
文摘The mechanism and the design parameters of blasting with air-decking are studied. The theory of detonation waves is used to investigate the processes of the one-dimensional plane detonation wave within a borehole. The interac- tion of the rarefaction wave with an interface and reflection on a rigid wall is also analyzed. The same courses of the shock wave are also investigated. This decides the distribution of the pressure of the explosion products changing with time along the borehole. Based on the above theoretical analysis, two conditions should be met for a reasonable range of values of the air-decking ratio in blasting rock. First, the rarefaction wave from the contact interface between detonation products and air reaches the bottom earlier than that of the reflected shock wave from the end of the stemming. Second, the reflected shock wave reaches the contact interface between the detonation products and air earlier than that of the reflected rarefaction wave from the bottom of the borehole. Finally, the reasonable value of the air-decking ratio must be decided theoretically in air-decking blasting. For different explosives, the reasonable range of air-decking ratio varies from 0.15 to 0.4. This result is well consistent with what was obtained by previous researchers.
文摘In recent years, China's overall social and economic system has undergone rapid and effective development under the promotion of personnel in various scientific research aspects. Driven by the economy, many industries in China have encountered many challenges with the advantages of such a large economic environment, but not only many challenges appear, but also challenges have also brought a lot of development opportunities. Enterprises to seize these opportunities can greatly promote their own economic rapid and effective development. Driven by the development of the social and economic system, the coal mining industry continues to develop through many measures. However, at present, the open-pit coal mines in China will produce a great vibration during blasting, which has brought a lot of harmful effects to the coal mining land. If these harmful effects are not effectively controlled, then for the coal mining enterprises will not only cause great damage to the machinery and equipment, in many cases, there will even endanger the life safety and property safety of the personnel on the site.
基金supported by the National Natural Science Foundation of China (No.50574076 and No.50838006)
文摘A precondition for correctly analyzing the stability of a slope and designing its bracing structure is to study and determine the influence of excavation blasting on the properties of weak intercalation in the layered rock slope. On the basis of in-situ stratification-cracking blasting tests, the properties of weak intercalation were investigated using the LS-DYNA3D program. The displacement distribution and compactness of weak intercalation at different positions away from the charge center and their various laws are discussed. The critical displacement of stratification-cracking （0.1 mm） was obtained, and an approximate expression of compactness were deduced. Furthermore, through the simulation of a layered rock blasting under the same geological conditions, the stratification-cracking effect of deep-hole blasting on the properties of weak intercalation was compared with that of short-hole blasting, and the influencing differences, in addition to their causes, were analyzed. The results indicated that the blasting cavity of weak intercalation in short-hole blasting with a radius of 40 mm was nearly a circle, whose radius was about 28.7 cm; whereas in deep-hole blasting with a radius of 150 mm, the shape of the blasting cavity was different from that in short-hole blasting, the radius of the cavity behind the charge （89.1 cm） was further smaller than those of the other three （138.7 cm）, and there were sharp crinkles on the surface of weak intercalation. When the distance from the charge center （DCC） was less than 40 and 150 cm in short-hole and deep-hole blasting, respectively, the displacement of weak intercalation was reduced remarkably with the increase in DCC.
基金National Natural Science Foundation of China （No. 51304087） Foundation Projects of Yun- nan Province （No. KKSY201404056, No. KKSA201121083）
文摘This paper numerically simulates the stress development and generates a three-dimensional model of the medium-length hole blasting in infinite rock mass for continuous charge and divided charge in blasting by using the large-scale nonlinear dynamic analysis software LS-DYNA and the elastic-plastic model ~*MAT_PLASTIC_KINEMATIC and JWO-EOS.The differences of the decreasing rate in Von Mises effective stress of blasting,element effective stress peak of free surface,bore wall stress and acceleration are investigated.It is shown that divided charge could greatly improve the blasting effect by engineering blasting practice.
基金National science and technology signifi cant special(No.2024ZD1003406)Natural Science Research Project of Colleges and Universities in Anhui Province(No.2024AH050374)National Natural Science Foundation of China(Grant No.52274071).
文摘The advancement of intelligent mining in open-pit operations has imposed higher demands on geological transparency,aiming to provide a robust foundation for intelligent drilling and charging.In this study,a linear array of 120 nodal seismometers was deployed along the surfaces of the C8 and C9 platforms at Fenghuang Mountain to investigate cavities within the rock mass and prevent improper intelligent charging.The seismometers were 1 m apart along measurement lines,with a 2-m spacing between lines,and the monitoring time for each line was set at 2 h.This deployment was paired with spatial autocorrelation and station autocorrelation to analyze ambient noise seismic data and image the velocity and structure within the rock mass.The results demonstrate that the locations and sizes of cavities or loose structures can be accurately identified at the prepared excavation site.Compared with traditional geological exploration methods for openpit mines,the approach in this study off ers higher accuracy,greater efficiency,reduced labor intensity,and insensitivity to water conditions.Ambient noise seismic imaging for detecting adverse geological conditions in open-pit mines provides critical insights and references for intelligent mining advancements.
基金supported by the National Key Research and Development Program of China(No.2022YFC2903902)the National Natural Science Foundation of China(Nos.52204080and 52174070)the Fundamental Research Funds for the Central Universities of China(No.2023GFYD17)。
文摘Accurately predicting the powder factor during blasting is essential for sustainable production planning in low-grade mines.This research presents a method for predicting powder factor based on the heterogeneity of rock mass rating(RMR).Considering a low-grade metal mine as an example,this study exploited geostatistical methods to obtain independent RMR for each block unit.A three-dimensional spatial distribution model for the powder factor was developed on the basis of the relationships between the RMR and the powder factor.Subsequently,models for blasting cost and mining value were built and employed to optimize the open-pit limit.The multi-variable model based on the RMR performed well in predicting the powder factor,achieving a correlation coefficient of 0.88(root mean square error of 4.3)and considerably outperforming the uniaxial compressive strength model.After model optimization,the mean size and standard deviation of the fragments in the blast pile decreased by 8.5%and 35.1%,respectively,whereas the boulder yield and its standard deviation decreased by 33.3%and 58.8%,respectively.Additionally,optimizing the open-pit limit using this method reduced the amount of rock,increased the amount of ore,and lowered blasting costs,thereby enhancing the economic efficiency of the mine.This study provides valuable insights for blasting design and mining decisions,demonstrating the advantages and potential applications of powder factor prediction based on the heterogeneity of rock mass quality.
基金provided by MULUniversidad Politecnica de Madrid
文摘The paper reviews the development of prediction formulas for the fragmentation from bench blasting.Much attention has been paid to the Kuz-Ram model,its development and errors,and the mean vs.median misunderstanding.The work by the US Bureau of Mines(USBM)and Chung and Katsabanis are also reviewed,as well as the two Julius Kruttschnitt Mineral Research Centre(JKMRC)models,i.e.the crush zone model(CZM)and the two-component model(TCM),which were developed to cope with the underestimation of blasting fines.The change brought by the Swebrec distribution and the associated Kuznetsov-Cunningham-Ouchterlony(KCO)model is described.Studying distribution-free fragment sizes xP for an arbitrary mass passing P led to the discovery of the fragmentation-energy fan,and with the help of dimensional analysis,to the new fragmentation prediction model xP-frag,which has much lower errors than those of the Kuz-Ram and CZM models.
基金the financial support by the National Natural Science Foundation of China(NSFC)(52178324).
文摘Bench blasting is commonly used in open-pit mining.Some design parameters such as positions of hole packing and caving holes have great influences on the blasting effects.In this work,with a hybrid discrete-finite element method,numerical simulations of bench blasting are conducted,capturing the whole continuous-discontinuous processes.Considering two engineering cases,the influences of hole packing and caving holes are evaluated.The numerical results not only lead to some improved designs by relocating the packing positions and caving holes but also indicate the reliability of the adopted numerical tools.
文摘Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in these industries, it can also have multiple adverse environmental impacts. One such effect is flyrock, which poses risks to nearby machinery, and residential structures, and can even lead to injuries or fatalities. To optimize blasting efficiency as well as restrict side effects, prediction of the blast aftereffects is vital. Therefore, the present work focuses on using two machine learning methods to predict the velocity of flyrock in the open pit mine. To address this issue, a comprehensive dataset was gathered from the open pit mine. Then, Decision Tree and Random Forest algorithms were employed to predict flyrock velocity. The Random Forest model demonstrated superior performance compared to the Decision Tree model. Nonetheless, the performance of the Decision Tree model was deemed satisfactory, as evidenced by its coefficient of determination value of 0.83, mean squared error (MSE) of 4.2, and mean absolute percentage error (MAPE) of 5.6%. Considering these metrics, it is reasonable to conclude that tree-based algorithms can be effective in predicting flyrock velocity.
