A model recognition method for the on-line optimal control of the parameters ofthree-cone blast drills is developed. It takes a few of on-line measurements and has a rapidoptimization speed. The mathematic model for o...A model recognition method for the on-line optimal control of the parameters ofthree-cone blast drills is developed. It takes a few of on-line measurements and has a rapidoptimization speed. The mathematic model for on-line optimal control of the parameters and thedetermination of the parameters in the model are also presented.展开更多
Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways.With the advent of digital electronic detonators and the need for increased production ...Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways.With the advent of digital electronic detonators and the need for increased production efciency,the traditional blasting design is no longer suitable for deep hole blasting.In this paper,a disperse charge cut blasting method was proposed to address the issues of low excavation depth and high block rate in deep hole undercut blasting.First,a blasting model was used to illustrate the mechanism of the deep hole dispersive charge cut blasting process.Then,continuous charge and dispersed charge blasting models were developed using the smooth particle hydrodynamics-fnite element method(SPHFEM).The cutting parameters were determined theoretically,and the cutting efciency was introduced to evaluate the cutting efect.The blasting efects of the two charging models were analyzed utilizing the evolution law of rock damage,the number of rock particles thrown,and the cutting efciency.The results show that using a dispersed charge improves the cutting efciency by about 20%and the rock breakage for the deep hole cut blasting compared to the traditional continuous charge.In addition,important parameters such as cutting hole spacing,cutting hole depth and upper charge proportion also have a signifcant impact on the cutting efect.Finally,the deep hole dispersed charge cut blasting technology is combined with the digital electronic detonator through the feld engineering practice.It provides a reference for the subsequent deep hole cutting blasting and the use of electronic detonators in rock roadways.展开更多
With the development of fracture mechanics,the fracture plane control blasting with notched borcholes hascome into being.This technique is used to create a satisfactory presplit along the contour of an excavation inro...With the development of fracture mechanics,the fracture plane control blasting with notched borcholes hascome into being.This technique is used to create a satisfactory presplit along the contour of an excavation inrock.However,the amount of explosive loaded in each hol usually is determined by trial and error.Because ofthis,two approaches estimating the amount of explosive for the blasting technique are suggested.展开更多
The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of m...The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of monitoring as the major factors for predicting the peak particle velocity(PPV). It is established that the PPV is caused by the maximum charge per delay which varies with the distance of monitoring and site geology. While conducting a production blasting, the waves induced by blasting of different holes interfere destructively with each other, which may result in higher PPV than the predicted value with scaled distance regression analysis. This phenomenon of interference/superimposition of waves is not considered while using scaled distance regression analysis. In this paper, an attempt has been made to compare the predicted values of blast-induced ground vibration using multi-hole trial blasting with single-hole blasting in an opencast coal mine under the same geological condition. Further,the modified prediction equation for the multi-hole trial blasting was obtained using single-hole regression analysis. The error between predicted and actual values of multi-hole blast-induced ground vibration was found to be reduced by 8.5%.展开更多
The cavity formation and propagation process of stress wave from parallel hole cut blasting was simulated with ANSYS/LS-DYNA 3D nonlinear dynamic finite element software. The distribution of element plastic strain, no...The cavity formation and propagation process of stress wave from parallel hole cut blasting was simulated with ANSYS/LS-DYNA 3D nonlinear dynamic finite element software. The distribution of element plastic strain, node velocity, node time-acceleration history and the blasting cartridge volume ratio during the process were analyzed. It was found that the detonation of charged holes would cause the interaction of stress wave with the wall of uncharged holes. Initial rock cracking and displacement to neighboring uncharged holes become the main mechanism of cavity formation in early stage.2008 University of Science and Technology Beijing. All rights reserved.展开更多
According to the neural network theory, combined with the technical characteristicsof the hole-by-hole detonation technology, a BP network model on the forecast forblasting vibration parameters was built.Taking the de...According to the neural network theory, combined with the technical characteristicsof the hole-by-hole detonation technology, a BP network model on the forecast forblasting vibration parameters was built.Taking the deep hole stair demolition in a mine asan experimental object and using the raw information and the blasting vibration monitoringdata collected in the process of the hole-by-hole detonation, carried out some training andapplication work on the established BP network model through the Matlab software, andachieved good effect.Also computed the vibration parameter with the empirical formulaand the BP network model separately.After comparing with the actual value, it is discoveredthat the forecasting result by the BP network model is close to the actual value.展开更多
In the study of the application effectiveness of deep-hole controlled pre-splittingblasting technology,it was found through laboratory micro test and field study on a mine insouth China that under the technology,coal ...In the study of the application effectiveness of deep-hole controlled pre-splittingblasting technology,it was found through laboratory micro test and field study on a mine insouth China that under the technology,coal masses produce many irreversible cracks.Afterblasting,the nearer the distance from blasting hole,the larger the BET surface areaand volume ratio of the infiltration pore are;they increased by 11.47%and 5.73%,respectively.The coefficient of air permeability is increased 4 times.After 3 months,the gasdrainage rate was increased by 66%.In the first 15 days,the cumulative pumped gas was1.93 times of blasting before.The average absolute gas emission decreased by 63.46%.Experimental results show that deep-hole controlled pre-splitting blasting not only preventscoal and gas outburst,but also gives good economic results.展开更多
The scalloped medium-length hole blasting mining method used in Dahongshan Copper Mine accounted for more than 61%of the total amount of mining,but the large boulder yield restricted the intensity of ore supply for mi...The scalloped medium-length hole blasting mining method used in Dahongshan Copper Mine accounted for more than 61%of the total amount of mining,but the large boulder yield restricted the intensity of ore supply for mines,and the average boulder yield was as high as 22.7%.In order to develop the mine production efficiency,the circular medium-length hole blasting technology was proposed and field tests were carried out.The test results showed that circular medium-length hole blasting mining can reduce the average boulder yield to 10.3%.Compared with the traditional scalloped medium-length hole blasting mining,the average boulder yield was decreased by 12.4%.The daily yield of ore for the panel on duty was increased by 152.29 t,and the growth rate was 51.1%.The new technology can reduce the time for the handling of boulder and the consumption of explosives and detonators for recrushing,and increase the efficiency of mining while reduce the mining cost,which has received good blasting effects.展开更多
Time interval of short delay ignition is an important factor to affect theefficiency of blasting cuts. The motion process of rock pieces in the cut cavity is analyzed, amechanical model to calculate the delay time of ...Time interval of short delay ignition is an important factor to affect theefficiency of blasting cuts. The motion process of rock pieces in the cut cavity is analyzed, amechanical model to calculate the delay time of parallel hole cuts is presented for tunnel blasting,and a theoretical method to determine the volume ratio (the clearage rate) of the rock pieceswithin the cut cavity at different moments is proposed for the blasting cut with an empty hole.Numerical analysis results show that the optimal delay interval is proportional to the boreholedepth. The suggested results are of practical value to the optimal design of the delay interval inmillisecond blasting related to the parallel hole cuts with an empty hole.展开更多
文摘A model recognition method for the on-line optimal control of the parameters ofthree-cone blast drills is developed. It takes a few of on-line measurements and has a rapidoptimization speed. The mathematic model for on-line optimal control of the parameters and thedetermination of the parameters in the model are also presented.
基金the State Key Development Program for Basic Research of China(2016YFC0600903)the National Natural Science Foundation of China(51934001).
文摘Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways.With the advent of digital electronic detonators and the need for increased production efciency,the traditional blasting design is no longer suitable for deep hole blasting.In this paper,a disperse charge cut blasting method was proposed to address the issues of low excavation depth and high block rate in deep hole undercut blasting.First,a blasting model was used to illustrate the mechanism of the deep hole dispersive charge cut blasting process.Then,continuous charge and dispersed charge blasting models were developed using the smooth particle hydrodynamics-fnite element method(SPHFEM).The cutting parameters were determined theoretically,and the cutting efciency was introduced to evaluate the cutting efect.The blasting efects of the two charging models were analyzed utilizing the evolution law of rock damage,the number of rock particles thrown,and the cutting efciency.The results show that using a dispersed charge improves the cutting efciency by about 20%and the rock breakage for the deep hole cut blasting compared to the traditional continuous charge.In addition,important parameters such as cutting hole spacing,cutting hole depth and upper charge proportion also have a signifcant impact on the cutting efect.Finally,the deep hole dispersed charge cut blasting technology is combined with the digital electronic detonator through the feld engineering practice.It provides a reference for the subsequent deep hole cutting blasting and the use of electronic detonators in rock roadways.
文摘With the development of fracture mechanics,the fracture plane control blasting with notched borcholes hascome into being.This technique is used to create a satisfactory presplit along the contour of an excavation inrock.However,the amount of explosive loaded in each hol usually is determined by trial and error.Because ofthis,two approaches estimating the amount of explosive for the blasting technique are suggested.
文摘The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of monitoring as the major factors for predicting the peak particle velocity(PPV). It is established that the PPV is caused by the maximum charge per delay which varies with the distance of monitoring and site geology. While conducting a production blasting, the waves induced by blasting of different holes interfere destructively with each other, which may result in higher PPV than the predicted value with scaled distance regression analysis. This phenomenon of interference/superimposition of waves is not considered while using scaled distance regression analysis. In this paper, an attempt has been made to compare the predicted values of blast-induced ground vibration using multi-hole trial blasting with single-hole blasting in an opencast coal mine under the same geological condition. Further,the modified prediction equation for the multi-hole trial blasting was obtained using single-hole regression analysis. The error between predicted and actual values of multi-hole blast-induced ground vibration was found to be reduced by 8.5%.
文摘The cavity formation and propagation process of stress wave from parallel hole cut blasting was simulated with ANSYS/LS-DYNA 3D nonlinear dynamic finite element software. The distribution of element plastic strain, node velocity, node time-acceleration history and the blasting cartridge volume ratio during the process were analyzed. It was found that the detonation of charged holes would cause the interaction of stress wave with the wall of uncharged holes. Initial rock cracking and displacement to neighboring uncharged holes become the main mechanism of cavity formation in early stage.2008 University of Science and Technology Beijing. All rights reserved.
基金Supported by the National Natural Science Foundation of China(50778107)
文摘According to the neural network theory, combined with the technical characteristicsof the hole-by-hole detonation technology, a BP network model on the forecast forblasting vibration parameters was built.Taking the deep hole stair demolition in a mine asan experimental object and using the raw information and the blasting vibration monitoringdata collected in the process of the hole-by-hole detonation, carried out some training andapplication work on the established BP network model through the Matlab software, andachieved good effect.Also computed the vibration parameter with the empirical formulaand the BP network model separately.After comparing with the actual value, it is discoveredthat the forecasting result by the BP network model is close to the actual value.
基金Supported by Project from National Natural Science Foundation of China(50674111)the National key Technology R&D Program in 10th Five Years Plan of China
文摘In the study of the application effectiveness of deep-hole controlled pre-splittingblasting technology,it was found through laboratory micro test and field study on a mine insouth China that under the technology,coal masses produce many irreversible cracks.Afterblasting,the nearer the distance from blasting hole,the larger the BET surface areaand volume ratio of the infiltration pore are;they increased by 11.47%and 5.73%,respectively.The coefficient of air permeability is increased 4 times.After 3 months,the gasdrainage rate was increased by 66%.In the first 15 days,the cumulative pumped gas was1.93 times of blasting before.The average absolute gas emission decreased by 63.46%.Experimental results show that deep-hole controlled pre-splitting blasting not only preventscoal and gas outburst,but also gives good economic results.
基金National Natural Science Foundation of China (No. 51304087) Foundation Projects of Yun- nan Province (No. KKSY201404056, No. KKSA201121083)
文摘The scalloped medium-length hole blasting mining method used in Dahongshan Copper Mine accounted for more than 61%of the total amount of mining,but the large boulder yield restricted the intensity of ore supply for mines,and the average boulder yield was as high as 22.7%.In order to develop the mine production efficiency,the circular medium-length hole blasting technology was proposed and field tests were carried out.The test results showed that circular medium-length hole blasting mining can reduce the average boulder yield to 10.3%.Compared with the traditional scalloped medium-length hole blasting mining,the average boulder yield was decreased by 12.4%.The daily yield of ore for the panel on duty was increased by 152.29 t,and the growth rate was 51.1%.The new technology can reduce the time for the handling of boulder and the consumption of explosives and detonators for recrushing,and increase the efficiency of mining while reduce the mining cost,which has received good blasting effects.
基金This work was financially supported by the National Natural Science Foundation of China (No. 59974019)
文摘Time interval of short delay ignition is an important factor to affect theefficiency of blasting cuts. The motion process of rock pieces in the cut cavity is analyzed, amechanical model to calculate the delay time of parallel hole cuts is presented for tunnel blasting,and a theoretical method to determine the volume ratio (the clearage rate) of the rock pieceswithin the cut cavity at different moments is proposed for the blasting cut with an empty hole.Numerical analysis results show that the optimal delay interval is proportional to the boreholedepth. The suggested results are of practical value to the optimal design of the delay interval inmillisecond blasting related to the parallel hole cuts with an empty hole.