| In this paper, we carried on the thorough analysis and research at the feasibility of employ deep hole blasting technology in frozen hard rock of bedrock section, the control mechanism of the safety of frozen pipe. In the reference and the basis of summarizing the research status at home and abroad, discusses the optimal cutting parameters selection of the deep hole cut blasting in the frozen hard rock of bedrock section. For analysis of the security implications of the frozen pipe and frozen wall in deep hole blasting of a great control blasting, optimizing the charge of the surrounding hole and structure of explosive, then we can get the best effect of blasting on the basis of guarantee the safety of the frozen pipe and frozen wall. Using ANSYS/LS-DYNA numerical simulation software set up a cut blasting model by the bedrock section of a vertical shaft in huaibei, that is divided into a hollow hole with no hollow hole. Analysis the stress concentration in large diameter hollow hole and the impact on the blasting efficiency when blasting.By the numerical simulation of cut blasting we can be obtained that compared with no empty hole the cut blast with an empty hole have stress concentration effects and an empty hole is beneficial to the rock fragmentation by reflective stretching wave.Compared the economy and technical effect of two classes of cut blasting can be concluded that when drill ability and under the condition of drilling time allows, the use of large diameter empty hole is a kind of effective method of made good economic and technical effect.Through the field study study for more than a month can be obtained that we can not only acquire good blasting effect (hole utilization rate of90%or so), but also can ensure the safety of frozen pipes and wall by using the deep hole (4.2m) blasting, the smooth blasting at around hole, the differential blasting technology to reduce blasting quantity at a time in the frozen hard rock of bedrock section. |
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