Study On Optimum Design And Numerical Simulation Of Blasting Parameters Of Cutting Platform Of Yunxi 1360 Base Platform

According to the problems of excavation blasting effect was not ideal and was unable to meet the need of production in1360foundation platform engineering of the YunNan Tin Group, this paper had analyzed and researched systematically the entry driving cut blasting technology with the methods of theoretical analysis, field test and numerical simulation.Firstly, the cut blasting mechanism of rock was introduced systematically on the paper, for theoretical preparation of the tunneling blasting design and cutting test.Secondly, full face blasting excavation for the horizontal section roadway of the GaoFeng main ramp of1360foundation platform engineering of the YunNan Tin Group was designed and a total of17times cut blasting experiment was carried out in the trackless haulage roadway, which was used four kinds of hybrid cut of level3v-cut+the drum cutting on center, triple nine holes cut, triple diamond cut with double empty holes and the secondary six prism cut. According to contrast analysis of test data, we came to the conclusion that adopting level3v-cut+the drum cutting on center of3.4m deep hole could acquire the best and most stable blasting effect in the dense layer marble, which the average utilization rate of cutting holes were78.53%, the average cycle penetration was2.526m, contour shape and the blast slag without large rocks were very good. In broken rock or rock layers with thick argillaceous interlayer, the cut blasting effect of switching to use triple diamond cut with double empty holes of2.7m deep holes was best, which the average utilization rate of cutting holes was as high as87.04%, average penetration was2.285m, single entry profile forming was good and moderate rock burst slag was suitable for clearing away slag.Finally, because the center of the drum cutting played an important role in cut blasting effect, adopting the numerical simulation technology studied on the drum cutting specially. It introduced the process of entity modeling building with ANSYS/LS-DYNA program, finite element meshing, analysis of the results of numerical calculation, etc. Through two kinds of the drum cutting numerical simulation and comparison research, the result showed that empty holes were vital for the drum cutting, which were the main free surface for charging holes and had a strong attraction and guiding role for the spread of the rock mass stress wave. So it could effectively constraint the explosive energy. In the drum cutting of2.5m deep holes,1.7m charging and0.8m filling, the influence of explosive shock wave was focused on the charge within the period of the surrounding rock mass and influence on filling period of rock mass was very weak. Filling period rock was damaged mainly because of the power of explosive gas expanding. In the drum cut, concentrating explosive to the center as far as possible and grounding the charging hole with empty holes could achieve the best cavity effect.