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
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
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
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
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.
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.
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.
