Numerical Simulation Of Reasonable Mini-interval Time In Open-pit Mines Precise Blasting

Milli-second delay blasting is one of the main technologies of modern open-pit mines.It plays a key roll in improving the shatter efficiency of rocks and in the aspect of bringing down the influence of blasting vibration. ,this paper on the basis of modern blasting theories,the mechanism of milli-second delay blasting and choice of reasonable mini-interval time are deeply studied. Milli-second blasting was deep studied from two aspects,which was theoretical studying and numerical simulation.In theory, first the study histories and the state of research development of milli-second blasting over the world were introduced briefly, through rock constitutive model, the means to get the rock strength rule was deeply studied. then study the destroyed rock causation in blasting load. discuss on destroyed behavior of rock under the explosion of rock stress wave. meanwhile analyzes various facts influencing explosion effects.In numerical simulation, dynamical finite element analysis sotfware ANSYS/LS-DYNA was applied,in single free face ,dynamic stress distribution and its change rule of rock around two holes milli-second delay blasting were computed.the main research parameter changing and time interval to blasting effect. established a series of computations model, After the comparative analysis of the result, the combination of different parameters of stress distribution character had been confirmed, throught unfavorable smash point and the rock against the strength of the comparative analysis, looking for a different kind of the rocks reasonable time interval, hole-distance.The paper have important significance to development of precise blasting in open-pit mines.It provides the instructions of theory and technology for applying the Blasting Technology of"milli-second blasting", Thus with the applicability innovation and priority,it can be spread and used.